Flow bindings have been deprecated for a while.
The reason behind this change is that `declare var foo`
doesn't introduce a new local binding, but it represents
a global one.
* Install sourceMapSupport only when sourceMaps are requested
* Add tests for sourceMapSupport
* Fix sourceMap position for tests
* Fix gen_error file
* fix the test descriptions
* Refactor install sourceMap support
* Run sourceMapSupport only once
* Handle cases where sourceMaps is undefined
* No unneeded empty arrays in transform spread
Since Array.prototype.concat creates a new array from inputs, there's
no need to call it from a new empty array ([].concat()).
* [fixup] simplify detection of new array
* Fix transform-arrow-functions in { spec: true } shadowing
The function name matching the variable declaration name could
shadow the actual function object inside the generated function,
leading to invalid behavior due to holding a reference to the
original unbound function.
* Combine it with transform-function-name just to be sure in spec: false
* Revert "Fix transform-arrow-functions in { spec: true } shadowing"
This reverts commit 1cafe2561d0b0ddd181b956a85eb074621da12e8.
* Much simpler version of the above fix
* Missing fixture updates
* Avoid using rest/spread to make the tests pass on node 4
* ...actually update _all_ the fixtures
* Unify eslint/prettier config
Use a prettier config file and correctly configure trailing commas
Enable curly in babylon as in all other packages.
* Add experimental and codemods
* Properly guard for..in loops with Object#hasOwnProperty.
I noticed that babylon spends a lot of time in what we call *slow mode*
`for..in` when running in Node (on V8), and the reason for that is that
the version distributed on npm is build with *loose mode*, which turns
methods on the prototype into enumerable properties. Let's look at a
simplified example of the `State` class from `src/tokenizer/state.js`:
```js
class State {
constructor() { this.x = 1; }
clone() {
var state = new State();
for (var key in this) {
var val = this[key];
state[key] = val;
}
return state;
}
}
```
According to the specification the `State.prototype.clone` method is
non-enumerable. However when transpiling this with loose mode, we get
the following output:
```js
var State = (function() {
function State() { this.x = 1; }
State.prototype.clone = function clone() {
var state = new State();
for (var key in this) {
var val = this[key];
state[key] = val;
}
return state;
}
return State;
})();
```
So all of a sudden the `State.prototype.clone` method is enumerable.
This means that the `for..in` loop inside of that method enumerates
`x` and `clone` for `key`, whereas originally it was supposed to only
enumerate `x`. This in turn means that the shape of the result of a
call to `clone` will be different than the shape of a state that is
created via the `State` constructor. You can check this in `d8` using
the `--allow-natives-syntax` flag and this simple test driver:
```js
const s = new State;
%DebugPrint(s);
%DebugPrint(s.clone());
```
Using either the class version or the transpiled version we see:
```
$ out/Release/d8 --allow-natives-syntax state-original.js
0x2a9d7970d329 <State map = 0x2a9d40b0c751>
0x2a9d7970d3c1 <State map = 0x2a9d40b0c751>
$ out/Release/d8 --allow-natives-syntax state-loose.js
0x3729ee30d1b9 <State map = 0x3729af90c701>
0x3729ee30d251 <State map = 0x3729af90c7a1>
```
So as you can see, the transpiled version (using *loose mode*) produces
a different shape for the result of `clone`, whereas the original
version is fine. This pollutes all sites which use either a state
created from the `State` constructor or returned from the `clone`
method. The original one has only the `x` property in either case,
whereas in the transpiled version the result of `clone` has properties
`x` and `clone` on the instance.
To mitigate this effect, it's best to guard the `for..in` loops with
`Object.prototype.hasOwnProperty` calls, such that the actual body of
the loop only deals with own properties and not with properties from the
prototype chain. This change does exactly that for the two affected
`clone` functions.
In addition to the performance hit because of the unnecessary
polymorphism, there's also the performance hit because of the *slow
mode* `for..in` itself, which has to collect the properties from the
instance plus the prototype. Ideally the prototype properties shouldn't
be enumerable to avoid this whole set of problems. I see a couple of
possible solutions:
1. Distribute the original ES2015 version via npm.
2. Don't use loose mode, so that `Object.defineProperty` is used
instead, correctly passing `enumerable:false`.
3. Globally change loose mode in Babel to generate the correct and
fast `Object.defineProperty` instead.
I'd personally prefer a combination of 1. and 3. here, but I'm aware
that distributing the ES2015 code might not be an option yet. So the
mitigation of properly guarding the `for..in` here should already help.
But it'd be nice to have a discussion on using `Object.defineProperty`
in general, as I imagine that this could easily bite other applications
as well and this performance cliff is completely unobvious to
developers.
* Switch to Object.keys and Array.prototype.forEach.
- This is because with scoped packages the `latest` package was the first publish we did
- This happens to be beta.4..
- So in this case we should publish whatever version as latest anyway
* Consider instance type for polyfills.
* Add test cases for evaluated objects.
* preset-env fixtures: babel-polyfill -> @babel/polyfill
* Split up fixtures with evaluated variables.
* Add JSX Fragments to babel-types
* Support JSX fragments in the transform-react-jsx plugin
* Add tests JSX fragments
* Update helper-builder and transform plugin documentations for jsx fragment
* Add generator for jsx fragments
* Add test for jsx fragment generator
* Split jsx transform example into normal and fragment examples
* Remove unnecessary fields from ElementState in babel-helper-builder-react-jsx
* inline [skip ci]
* Use parseFunctionParams to parse method parameters
* [funct] Set this.state.inGenerator before parsing the function name/params
This allows "yield" inside generator parameters to be actually
parsed as a yield expression
* [funct] Disallow yield in function parameters
* [arrow] "yield" can start an arrow function (e.g. "yield => {}")
* [arrow] Disallow YieldExpressions inside arrow parameters.
* [err msg] Disallow yield as fn name in strict mode using checkReservedWord.
So Babylon throws "yield is a reserved word" instead of
a custom "Binding yield in strict mode"
* [err msg] "X is reserved in strict mode" should have precedence over "X is reserved", since it is more specific.
This was observable if "checkKeywords" is true and the word is both a keyword and a reserved
word in strict mode
* Disallow "yield" as an identifier inside generators
* [tests] Add tests, update wrong esprima tests and enable disabled esprima tests
* [tests] Move uncategorized tests to es2015/yield
* [tests] Update test262 whitelist
* Fix regression introduced by 8c77073
* [tests] Update flow whitelist
* Fix flow errors
- adds `get` and `set` kind in addition to `method` to the list of allowed class members for having a decorator,
- adds tests for this two cases (decorator + set and decorator + get)
* Fix OOB string character access in Printer#_maybeAddParen.
The `_maybeAddParen` method of the `Printer` class does
```js
const chaPost = str[i + 1]
```
without checking that `i + 1` is still within the bounds of `str`. It
seems like this triggers fairly often that the `str[i + 1]` access is
out of bounds. The first out of bounds access will turn the KeyedLoadIC
(in case of V8) into *MEGAMORPHIC* state, which is significantly slower
for strings (there's a fix in flight for V8 to mitigate the cost a bit
in that case). Even worse than that, the out of bounds access also
pollutes the later comparisons, namely
```js
chaPost === "/"
```
and
```js
chaPost === "*"
```
which are now no longer monomorphic on strings, since `chaPost` was
sometimes `undefined`.
This is a non-breaking performance fix, which improves babel execution
on the [web-tooling-benchmark](github.com/v8/web-tooling-benchmark)
workload by around 6-9%.
* Restructure and optimize the code a bit.
* Added tests for ifThrowNamespace flag
* JSX transformator could work with XMLNamespaces (ifThrowNamespace flag)
* Use template literal instead
* Attempt to reword the message
* Added docs
* Reworded docs
* Reworded docs
* Fixed missing space in error message
The code
```js
linesInfo && linesInfo[type]
```
performs a lot of dynamic lookups on the `Boolean.prototype`, as the
*ToBoolean* operation let's `true` pass for `linesInfo` (which might
itself be concerning that this can be a boolean). Instead of the
coercion, the code should properly check for valid objects via `typeof`
and strict equality with `null` comparison.
This is a non-breaking performance fix.
Similar to the fixes in https://github.com/babel/babel/pull/6580 and
https://github.com/babel/babel/pull/6581, accesses of the form
```js
nodesOut[nodesOut.length - 1]
```
where `nodesOut` can be an empty array, are bad for performance in Node.
In this particular case it's easy to restructure the code a bit to not
require the array access at all, but just track the current `tail` as we
go.
This is a non-breaking performance fix.
* Fix path.popContext() to not try to load "-1" from contexts array.
The current implement of popContext does
```js
this.setContext(this.contexts[this.contexts.length - 1]);
```
even if `this.contexts` can be empty, which causes it to lookup the
property `"-1"`, which is not found on the array itself and obviously
also not in the `Object.prototype` and the `Array.prototype`. However
since `"-1"` is not a valid array index, but has a valid integer
representation, this is a very expensive lookup in V8 (and probably
other engines too, but that is probably less relevant, since Babel
most often runs on Node nowadays).
* Make zero check explicit (for readability).
Similar in spirit to https://github.com/babel/babel/pull/6580, the
current implementation did
```js
node.params[node.params.length - 1]
```
where `node.params` can also be empty, which causes it to lookup the
property `"-1"`, which is not found on the array itself and obviously
also not in the `Object.prototype` and the `Array.prototype`. However
since `"-1"` is not a valid array index, but has a valid integer
representation, this is a very expensive lookup in V8 (and probably
other engines too, but that is probably less relevant, since Babel
most often runs on Node nowadays). In V8 this causes a call to
the `%SetProperty` runtime function for each of these `"-1"`
property lookups, and in addition sends the whole `KeyedLoadIC`
to `MEGAMORPHIC` state, which also penalizes other accesses
on this line.
This is a small non-breaking performance fix.
Similar to the fixes in https://github.com/babel/babel/pull/6580 and
https://github.com/babel/babel/pull/6581, accesses of the form
```js
stack[stack.length - 1];
```
when `stack` can be an empty array are pretty bad for performance.
In this case it also breaks the type safety, since the function
`last<T>` is declared to only return values of type `T`, but
occasionally also returns `undefined` now, since the `stack` parameters
passed to it never contain a property `"-1"` and neither do the
`Object.prototype` or the `Array.prototype`.
This is a non-breaking performance fix, which adds proper checking
to ensure that `last` is only invoked on non-empty arrays.
* Initial version
* Replace .includes with .indexOf and better node set to visit
* Alphabetically sort es3 reserved words and make difference helper for readability
* Fix second Array.include error that was not polyfilled
* Move es3 keywords into separate babel-types helper and use in all es3 transforms
* Reference local plugin build directly for tests
* Try relative import for babel-types
* Update to scoped package name and beta 3
* Fix unscoped package import
* Replace local plugin reference with proper plugin name
* Removed index.js stub from packages/babel-core
Added "main":"./lib/index.js" entry to package.json to replace index.js in packages/babel-core
* Fix indentation of new main.
Previously, computed class properties would be evaluated every time a
new instance of the class was created. This means the property name
may have changed between different instances, as well as potential side
effects.
This commit fixes this by storing the computed value in a separate
variable.
* centralize plugin options
* Centralize plugins options
- move more options to the top
- move validations that depend on options to the top
* use isLoose option
* Move more validations to the top
* Move ref parameter for rewriteModuleStatementsAndPrepareHeader() to the top
* fix eslint errors
* remove unused parameter
* set default systemGlobal value
* Revert "Move ref parameter for rewriteModuleStatementsAndPrepareHeader() to the top"
This reverts commit b3855302d17fa19d8acb4c8accab3680c8d2710e.
* Revert "Move more validations to the top"
This reverts commit e5861d8a034ff8f553391f55654f753bcf428a5d.
* fix allowMutablePropsOnTags option usage
* improve naming
* change Contructor definition for sake of consistency
* move allowMutablePropsOnTags validation to the top
* add missing !
Supports:
```js
// these all should produce "code;" when generated
template`code;`();
template`${0}`(t.identifier('code'));
template`${'code'}`({ code: t.identifier('code') });
template`${t.identifier('code')}`()
template({})`code`();
```
Amusingly the pipeline OP "breaks" the readme formatting because Markdown likes the `|` character a bit too much. Escaping the `|` fixes this and makes the readme display properly
This prevents a requeued path from inheriting a totally wrong scope later on. I can't find exactly where this is happening, but either way a path should only inherit scope from it's ancestors.
* Add support for helpers dependencies.
They are used like this:
helpers.main = defineHelper(`
import dep from "dependency";
export default function main() { return dependency; }
`);
helpers.dependency = defineHelper(`ì
export default function dep() { return 0; }
`);
* Clone import references
* Don't make test helpers name depend on the order the tests are run
* Path#ensureBlock keeps path context
This ensures that if you're inside an ArrowFunction with an expression body (say, you're on the BooleanLiteral in `() => true`), you don't suddenly lose your path context after inserting a variable.
This is because of 82d8aded8e (diff-9e0668ad44535be897b934e7077ecea5R14). Basically, an innocent `Scope#push` caused my visitor to suddenly stop working. Now, we mutate the Path so it's still in the tree.
* Tests
* Use helper-builder-react-jsx inside plugin-transform-react-inline-elements.
This avoids duplicating the logic for converting jsx elements to plain JavaScript.
* Add a comment which explains the _jsx signature, [skip ci]
so it is a little bit easier to understand what all those .splice() calls do
* Re-name uncatagorised 1 and 2
* Move to es2015
* Add expected.json to parenthesized lhs object
* Orginize into parenthesized-lhs-array and parenthesized-lhs-object
* Remove uncategorised/33 because it was repeditive decorators/class-decorator
* Move uncatagorised/34 to decorators/class-decorator-assignment
* Move uncategorised/35 to decorators/method-decorator
* Move uncategorised/36 to decorators/class-decorator-setter
* Move uncategorised/37 to decorators/class-decorator-getter
* Move uncategorised/38 to decorators/class-decorators-multiple
* Clean up syntax
* Move uncategorised/39 to decorators/object-decorator
* Remove syntax in order to pass tests
* Re-add uncategorisd/33 as decorators/class-decorator-new-line
* Move class-decorator-new-line to class-decorator-same-line
* Remove babel-node from babel-cli
* Use new Array instead of Array for V8 optimization
* Remove extraneous use strict clauses
* Require babel-node in babel-cli
* Remove babel-node from babel-cli
* Require babel-node in babel-cli
* Remove babel-node executable from babel-cli
* Clean up babel-node from package.json
* outline of plugin to remove unused catch binding, test not passing
* plugin to remove unused catch binding
* Edit README.md and package.json
* tests for try catch finally
* Add test to handle case when binding is referenced and given new TypeError (not passing)
* Fix visitor to not remove catch clause param when binding being assigned a new value
* Improve naming of tests and explanations
* add test case for catch param not present and fix test for duplicate variable declaration
* Remove binding.constantViolations filter in visitor as superfluous
* Remove duplicate check that catch clause param present
* Alter visitor so returns out when catch binding is not an Identifier
* Created failing tests for ObjectPattern params and rewrote visitor so now passing
Took out the pass in visitor when param not an Identifier, wrote case to handle when param isObjectPattern, and wrote failing tests for when param isArrayPattern
* Handle case when param isArrayPattern, tests passing
* Update package.json to v7.0.0-alpha.20
* Revert visitor to only consider transform if param is Identifier
This separates `classPrivateMethods`'s dependency on
`classPrivateProperties`. It also starts a `PrivateName` at the hash
symbol, not the `Identifier`.
* Add --keep-module-extension option to babel-cli
* Rename keep-module-extension option to keep-file-extension; Change option to preserve all file extensions
* Return inserted/replaced paths
This gives `Path`’s replacement and insertion methods a consistent
return value: the inserted/replaced paths.
Before, they could return `undefined`, a `node`, or a the current path
inside an array. It was kinda pointless. But now they always return an
array of paths, which is useful for solving
https://github.com/babel/babel/pull/4935#discussion_r96151368.
* Return inserted nodes and not BlockStatement
Addded test for bug #4363
* Cleanups
- `#replaceWith` will now return the current path if it's the same node
- `#insertAfter` and `#insertBefore` use public Path APIs now
- Makes container insertion faster (single splice call)
- Use public APIs in container insertion
- Replacing a statement with an expression returns the expression's path
- Replacing an expression with multiple statements returns the inserted
closure's body's paths.
* Add failing test case for object rest after array rest.
Discovered while upgrading https://github.com/meteor/babel to Babel 7.
The error is:
1) babel-plugin-transform-object-rest-spread/object rest with array rest:
TypeError: /Users/ben/dev/babel/packages/babel-plugin-transform-object-rest-spread/test/fixtures/object-rest/with-array-rest/actual.js: Property id of VariableDeclarator expected node to be of a type ["LVal"] but instead got null
at Object.validate (packages/babel-types/lib/definitions/index.js:73:13)
at validate (packages/babel-types/lib/index.js:460:9)
at Object.builder (packages/babel-types/lib/index.js:428:7)
at Object.RestElement (packages/babel-plugin-transform-object-rest-spread/lib/index.js:157:41)
at NodePath._call (packages/babel-traverse/lib/path/context.js:53:20)
at NodePath.call (packages/babel-traverse/lib/path/context.js:40:17)
at NodePath.visit (packages/babel-traverse/lib/path/context.js:84:12)
...
* Fix object rest following array rest. (#6213)
* Avoid treating array ...rest elements as object ...rest properties.
* Also avoid treating ...rest parameters as object ...rest properties.
Returning early if the parent was an ArrayPattern was not quite enough,
since a RestElement can appear as a parameter in a Function as well.
* Move RestElement parent check earlier in visitor method.
* Fix output directory if filename is given
* Add test for relative output path
* Add option to define output dir relative to input
* Add tests for --copy-files
* Test error handling for wrong arguments
* Redeclaring a variable counts as a modification.
Fixes#6217.
* Remove "existing" logic from Binding.
Was added in #5745, but no longer triggered since 6536e605a.
* Add support for class private methods
This commit adds parser support for the TC39 Stage 2 Private Methods
proposal.
This commit also changes "key" in ClassPrivateProperty from an
Identifier to a PrivateName, as well as disallowing #constructor as a
valid private field name.
* Add tests for string literal get/set/async
These should be treated as regular methods and not special get/set/async
behaviour.
* Add tests for class private methods
This also removes a test from the Test262 whitelist that failed before
the changes for private methods support and now passes.
* Modify class private prop tests for PrivateName
* Add class private prop tests for #constructor
* Fix existing ASI test case failure
* Removed the deprecated jsx pragma detection code and the concerned tests that included jsx-pragma
* Removed extra tests
* Restored packages/babel-plugin-transform-react-jsx/test/fixtures/react/honor-custom-jsx-pragma-option/
* Added JSX_ANNOTATION_REGEX
* Reverted the tests for jsx-pragma-options and removed those which throw deprecated message
* Fix bad Scope#parent caching
Now, we traverse the path until we find a parent scope.
Fixes#6057.
* Fix bad merge
* Remove cached data
* I need to stop using Github editor
* Fix infinite loops due to scopable paths being moved up
This reverts the former fix done in #5743 and always requeues
BlockStatements when they get created.
This also fixes a bug in babel-generator which would indent code
even though no comments are present.
* Allow NodeJS v8.4 experimental HTTP2
Native NodeJS HTTP/2 support experimental though, so might not be worth merging this
* Linter picked up on a line with only spaces
Removed the spaces
* added --delete-dir-on-start option
added --delete-dir-on-start-option to delete dir on start of compilation to remove deleted files from the orignial files from the --out-dir
* added option --delete-dir-on-start
added --delete-dir-on-start that option will delete the --out-dir before the compilation of code to remove the deleted files from the source from the out directory
* added --delete-dir-on-start option
added --delete-dir-on-start-option to delete dir on start of compilation to remove deleted files from the orignial files from the --out-dir
* bug removed deleting the correct dir
in the previous code, the source dir was deleted each time rather than deleting the out dir
* Remove shorthand
* Prevent babel-cli option from reaching babel-core
* Lint
I can never remember the syntax and end up coming here to copy/paste this snippet all the time.
I assume other people want to as well, or at least make it clear for newbs that this can be used with Node without them having to scroll.
* for-of: IteratorClose spec compatibility.
See #3:
https://tc39.github.io/ecma262/#sec-iteratorclose
* Update spec fixtures for for-of.
* Fix IteratorClose case for remap-async-to-generator.
* Fix IteratorClose case for async-generator-function test output.
* Modify few tests according to iteratorClose fix.
* Fix iteratorClose for helpers.slicedToArray also.
* Update iteratorClose fixture for commonjs.
* Don't merge test options.
Particularly, I don't want `lodash/merge` to merge my specific plugins
with the general test plugins. It led to odd behavior where I could
enable a loose transform in my specific test, just to have it overridden
by the test fixture's general options.
* Need options
Given that it refers to an identifier, it's somewhat confusing to have
to use .name.name to get the actual string. The type declared within
types.js is also incorrect, which this commit fixes.
The for-in loop in helpers.defineEnumerableProperties doesn't iterate over Symbols.
If Object.getOwnPropertySymbols exists, include the discovered values when defining properties.
* Changed updateExpression to report itself as violation instead of its argument
* Update getBindingIdentifiers to work with forXStatement and return proper node as violation
* Updated unaryExpression violation to be consistent with changes.
* Removed the deprecated jsx pragma detection code and the concerned tests that included jsx-pragma
* Removed extra tests
* Restored packages/babel-plugin-transform-react-jsx/test/fixtures/react/honor-custom-jsx-pragma-option/
* Allow nightly Yarn builds to be used
Fixes:
```
C:\src\babel (fix-it-fix-it-fix-it-fix-it) (babel)
λ yarn
yarn install v1.0.0-20170811.1240
[1/5] Validating package.json...
error babel@: The engine "yarn" is incompatible with this module. Expected version ">=0.27.5".
error Found incompatible module
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
```
* Use Yarn 0.28.4 to fix build
This change has two reasons:
- The object was actually used as a map
- Using an object leads some problems with the
private_class_fields/constructor.js test, since
`tests[test_name] || {}` returned the Obejct
constructor instead of an empty object.
So, I was reading the new Flow type strictness and noticed
https://flow.org/blog/2017/05/07/Strict-Function-Call-Arity/
Specifically, I wondered whether the `sum_all` example would copy the
arguments into an array, then loop over. Sadly, it does.
```js
function sum_all(...rest) {
let ret = 0;
for (let i = 0; i < rest.length; i++) { ret += rest[i]; }
return ret;
}
// output
function sum_all() {
var ret = 0;
for (var _len = arguments.length, rest = Array(_len), _key = 0; _key < _len; _key++) {
rest[_key] = arguments[_key];
}
for (var i = 0; i < rest.length; i++) { ret += rest[i]; }
return ret;
}
```
But then I noticed if I changed `let i = 0` to `let i: number = 0`, it
worked directly on `arguments`. That lead me down a rabbit hole to
`Path#_guessExecutionStatusRelativeTo`. When tracing through, the last
comparison made no sense to me. It was trying to find the index of
`"init"` in a list of `["declarations"]` and `"body"` in `["directives",
"body"]`. Red flags and such.
But it makes sense when you're trying to compare the visitor order of
the common ancestor path. Then we're trying to find `"init"` in a list
of `["init", "test", "update", "body"]`. Oh, and there's `"body"` in
there too! And now we know the `ForStatement`'s `init` is executed
before the `body`.
Arrow functions can't be entrly skipped while traversing because this
references inside of them needs to be transformed, so I added a check
which prevents return statements inside arrow functions from being
saved for the transformation.
Fixes#5817 (regression)
* Move babel-standalone into main Babel repo
* Don't try to gather coverage data for babel-standalone test
* Fix JSX test
* Always use npm v4 on Travis
* Include pull request number as part of version number
* Cherry-picking 5721b2e43e
Remove deprecated packages to prevent Babel v6 files from being pulled in
* Use RootMostResolvePlugin to dedupe packages
* Avoid destructuring so the build works on archaic Node.js versions
* - Fix version number
- Remove Babili packages (they should be in separate babili-standalone)
- Remove deprecated syntax-class-constructor-call
* - Remove more Babili packages
- Remove `babel-plugin-inline-replace-variables` for now as it pulls in Babel 6 stuff
* Actually remove reference to babel-plugin-undeclared-variables-check
* Add Babylon to root package.json so we hoist the right version. This fixes the tests.
* add transform-class-properties to stage 3, set spec mode to default
* update readme with examples; use `buildUndefinedNode()`; change behavior to always define both static and nonstatic class properties regardless of spec/loose mode; update tests
* Add babel-plugin-syntax-typescript and babel-plugin-transform-typescript
* Add babel-preset-typescript
* Remove unnecessary handler for JSXOpeningElement
* Use `t.isFoo(node)` instead of `node.type === "Foo"`
* Clean up parameter property assignment generation
* Don't use function for `isSuperCall`
* slice -> shift
* Calculate sourceFileHasJsx only if necessary
* Remove `export =` support
* remove some syntax readme newlines [skip ci]
* Integrate Test262
Introduce a GNU Make target for retrieving TC-39's Test262 suite and
validating parsing of the files it contains. Interpret each file as a
parser test in accordance with that project's `INTERPRETING.md`
document. Allow for the specification of allowed failures via a
"whitelist" file so that the test suite may help prevent regressions in
this project in situations where this project has known bugs. Initialize
the "whitelist" file with a listing of all tests that are currently
failing. Extend the continuous integration environment's configuration
to automatically run these tests.
* use graceful-fs and latest yarn on travis
* update lerna and lerna-changelog
* Lerna: enable yarn, yarn workspaces [skip ci]
* use older version of Babel since it matches on semver (cannot be the same version)
* install yarn version
* revert node engine change
* update flow
* circle ci on 8
* update lock
* Arrow fns can't be used as the left side of a binary or ternary expression
Fixes#536
* Add test for logical expression with arrow function
* Fix eslint
* babel-generator: Add TypeScript support
* Remove type declarations; not published from babylon
* Remove TODOs
* Consistently use `this.word` for tokens that are words
* allow PluginPass.file.addImport to create empty import statements; fixes#6021
omitting addImport's second argument creates an import statement with an
empty `specifiers` array i.e. an empty import statement:
plugin:
Program (path, { file }) {
file.addImport('foo-bar/register')
}
output:
import "foo-bar/register";
* babel-types: Add TypeScript definitions
* Add missing builders
* Allow arrow function to have "generator"
* Replace link to resolved issue with comment
* Re-add 'generator' to functionCommon
* Create "babel-helper-wrap-function"
It contains the logic to wrap a function inside a call expression.
It was part of the "babel-helper-remap-async-to-generator" package, but
it is needed to transpile "function.sent"
* Create "babel-transform-function-sent"
It transforms the "function.sent" meta property by replacing it with
"yield" and making the generator ignore the first ".next()" call.
* "function.sent" is the last value passed to .next(), not the first one
* Disable exec tests on old node
* Fix flow error
* Add "transform-function-sent" to "stage-2" preset
* Do every trasformation in one traversal
* Test for "yield function.sent"
* [skip ci]
* Fix some typos [skip ci]
* Use first binding for multiple var declarations
Since var declarations after initial binding have no effect, use the
first declaration. Fixes#2378
* Include hoisted function bindings
* Missing newline in expected.js
* Simplify constantViolations in new Binding on existing
* clarify comment language
* Add optionality to catch bindings (plus tests)
* Update ast/spec, README, set param to null if no param with plugin optionalCatchBinding
* Fix: wrap param = null in else case
* Fix tests for optional catch binding; add tests which include finally clause
* Figuring out where to place throw statement
* Restored path argument destructuring
* New approach using comma expressions for assignments
* Moved throwNode into body of forXstatements
* Refactored with helper function and ensureBlock, additional tests for update exprs
* Added exec tests for all violations
* Hoisted helper function for comma expression outside of visitor
* Remove parens around break and continue
Fixes#5742
* Fix space in doc comment
* Add some tests
* Remove newlines within CommentBlock
* Prevent newline before/after label
* Remove reference to node
* Check for label within startTerminatorless
* Print block instead of single line comment
* Clean up
* Add new.target transform
* Catch new.target under only an arrow function
* More unsupported reflect.construct cases
* Fix node 4 test
* Do not transform Methods
* More tests
* Properly setup function inheritance test
* Tests tests tests
* Fix ES6 class's new.target
* Remove expected output thats supposed to throw.
* Remove whitespace generation and rely on default printing
Changes to printing:
* Add newline after last empty SwitchCase
* Add newlines around block comments if they are non-flow comments or contain newlines
* Fix a few more fixtures
* Fix destructured exports
- adds a failing test based on description in #5768
- handles ObjectPattern and ArrayPattern
* use export assignment template
* Distinguish between ternary's : and arrow fn's return type
* Correctly parse nested arrow functions inside conditional expressions
Defer the conversion of arrow function parameters to assignable nodes so that
it is possible to use the (invalid) ast to get the exact position of the (wrong)
arrow functions.
* Check params of arrow fns w/ type params or w/o return type
* Fix also async functions
* Add test from prettier
https://github.com/prettier/prettier/issues/2194
* Don't check arrow params if they are valid at the first attemp
* Use state instead of relying on the "noArrowParamsConversion" parameter
* Remove noArrowParamsConversion
The parsing of private fields checks whether or not it is within a
class to determine if it is valid or not. However, the state.inClass
property is incorrect as it marks it as outside a class when the inner
class is closed.
This commit fixes this problem by replacing the state.inClass property
with a class nesting counter.
Given that private fields can only be used within classes, any code
using them must be in a strict mode context. As private fields cannot
be deleted, throw an early SyntaxError.
* Remove node 7 and introduce node 8 in travis config
Progress on #5804
* Run yarn install with node 8
Progress on #5804
* Remove expose_debug_as from tests; replace with expose_gc_as
Fixes#5804
* Remove dashed options since they aren't listed
* Revert "Remove dashed options since they aren't listed"
This reverts commit f826167e320ee85331e09ac63b5674401cac6236.
This way, it quickly returns from the conditions. The first nil will
now exit, instead of checking every nil.
This also allows conditionalChaining inside a container to still
operate the container.
* Wrap an arrow function in parentheses if it the test of a conditional expression
Fixes#5819
* Use ConditionalExpresion to check if () => {} should be wrapped
* Move `t.isTaggedTemplateExpression()` from ArrowFunctionExpression to
ConditionalExpresion
* [test] `await (() => {})` needs the parentheses
* [test] (a ? b : c)`` needs the parentheses
* Spec compatibility for template literals.
* Update preset-es2015 `spec` expected case.
* Prevent array mutability by replacing `shift`.
* Fix condition for single item.
* Group concats to ensure toPrimitive sequence.
* Update function test case.
* Add semi for function test case.
* Simplify concat call expressions creating.
* Fix some cases with multiple idengifiers.
* Add test case with different literals.
* Add test case for `Symbol()` and toPrimitive order
* Add actual literal case.
* Add minNodeVersion to template literals order.
* Flip the logical expression.
* Update README for template literals spec option.
* docs [skip ci]
* Add plugin for import.meta proposal
Fixes https://github.com/babel/babylon/issues/539
* Tests for assignment/mutation of import.meta
* Use correct identifier in failure message
* Simpler & more consistent script errors for import.meta
The arguments of a function would be unnecessarily copied if there was
a nested function that had a parameter with the same identifier as the
rest parameter for the outer function. This checks the scope of the
parameter is correct before deoptimising.
Fixes: https://github.com/babel/babel/issues/5656
Refs: https://github.com/babel/babel/issues/2091
* Add support for declare export
* Do not allow declare module inside declare module
* Reallow module exports outside module
* Add handling of `declare export default`
Add check for multiple module.export declarations
* Disallow export let/const/type
Refactor parsing object properties to share more code and add support
for getters and setters
* Rename tests
* Update test fixtures
* Optimize for performance
* disallow declare export interface outside of module
* Refactor code to be more readable and less lookahead
* Add comments
* Add test for export star as
* Test for number literal getter/setter
* Add more tests
* Fix tests
* Allow union types and correctly eat semi after type
* Use non computed keys
* Fix tests
* Add support for flow type spread (#418)
* Add support for flow type spread
* Broaden spreadable types from primary to all, more tests
* Eliminate variance sigil for type spreads, better errors, fix tests
# Conflicts:
# src/plugins/flow.js
* Fix tests
* Add support for flow type spread
* Broaden spreadable types from primary to all, more tests
* Eliminate variance sigil for type spreads, better errors, fix tests
* Test runner: Detect extra property in 'actual' but not in 'expected'.
Also update all expected.json where this would result in errors.
* Include rmExpected.js script in case it is needed again
* master:
Upgrade flow to 0.41
Throw error if new.target is used outside of a function (#402)
Fix watch command (#403)
Update yarn lock
Fix parsing of class properties (#351)
# Conflicts:
# src/parser/statement.js
# test/fixtures/experimental/class-constructor-call/illegal-key/options.json
* Fix negative number literal typeannotations
Also use parseLiteral() to parser string and number literal typeannotations
so that future changes (estree) to literals are also reflected to flow.
* Instead of invalid fallthrough throw immediately
* Increase coverage and better error mesage
* Initial estree support for ClassMethod
* Handle literals for estree
* Fix regex
* correct output of regexp and regenerate test
* Add tests for validation stuff with estree plugin
* Parse Properties correctly
This also refactors how babylon parses obj properties in general
so that this logic can be more easily extended.
* Run all throws-tests a second time with estree plugin
* Fix all throw tests
* Remove rebase conflict
* Correctly set kind
This ensures state.inMethod gets propagated correctly
* Add computed: false to methods with ident async
* Implement directive field on Directives
* Test invalid directives
* more tests
* [Flow] Function predicate declaration
The accepted syntax for function declarations is extended to allow
the following predicate declaration:
FunctionReturnType :=
Type
Predicate
Type Predicate
Predicate :=
%checks
%checks ( ConditionalExpression )
* [Flow] Minor tweaks and more examples to function predicates
* [Flow] Clean-up and better message for function predicates
* [Flow] Adding abstract function predicate example
* [Flow] Rearranging the `predicate` field to ease babel generator.
* Replace manual electron-to-chromium list and function with external library
* test fixtures for electron: Switch to electron 1.4, with known chrome version and update expected output
* update tests: electron 1.0 used chrome 49, not 50
* import only the relevant function from electron-to-chromium
* electron fixtures: Use number instead of string
* If both chrome and electron are defined, choose the lower version to preserve
* Add to test cases to verify correct handling of chrome number
* refactor(tokenizer): use class for keywork tokens
* refactor(tokenizer): re-use constacts in types
* refactor(tokenizer): binop token type
* feat(tokenizer): use beforeAndStartExpr for shortcut
* fix(tokenizer): typo in keywordTokenType
* refactor(tokenizer): don't use spread operator
* refactor(tokenizer): constant for isLoop, isAssign, prefix, postfix
* fix(tokenizer): remove constant beforeAndStartExpr
* style(tokenizer): space after comma
Adding the line `this.state = this.state.clone();` in a parser plugin
(specifically, in my case `parseExprAtom`)
would break decorators.
This change fixes that.
* Use fromCodePoint to convert high value unicode entities
* Include polyfill for String.fromCodePoint
* copy and adapt fromCodePoint into String.fromcodepoint
In order to avoid modifying String as the polyfill does, I've copied
the source from the polyfill and adapted it return the polyfill
function if the native version does not exist. Once support for node
versions that lack fromCodePoint is dropped, this polyfill can be
removed.
* move license notice to top of file
* Rename ios_saf in browserslist data to ios, ignore unknown browsers
browserslist queries, especially ones with percentages, often bring in mobile browsers that _probably_ have the similar support level as desktop ones, but since there's no support for them in the data, including them here would just lead to all plugins being enabled always.
It's also easy to get crazy things like `op_mini` or `and_uc` in the results.
Browserslist also reports iOS Safari as `ios_saf`, while the data uses `ios`, so it needs to be renamed.
* Fix lint
* Run tests of flow with babylon
* Fix travis
* Fix typo
* Again...
* Brtter hint
* proper exit code
* Fix some flase-positives and better reporting
* Enable some plugins, that flow supports by default
* Parse flow nested array type annotations like number[][]
Fixes#217.
* Do not parse a newline separated array statement into a flow type annotation
* Get rid of lineBreak dependency in flow.js in favor of higher level method
browserslist queries, especially ones with percentages, often bring in mobile browsers that _probably_ have the similar support level as desktop ones, but since there's no support for them in the data, including them here would just lead to all plugins being enabled always.
It's also easy to get crazy things like `op_mini` or `and_uc` in the results.
Browserslist also reports iOS Safari as `ios_saf`, while the data uses `ios`, so it needs to be renamed.
* Add code coverage from Babel tests
* Configure nyc correctly for Babel test coverage
* Guard against nyc config conflicts if Babel switches to nyc in the future
* Move .nyc_output from Babel build dir to root
* Use .gitattributes to ignore files with weird newlines
* [Flow] Make parameter names in function types optional
* [Flow] Anonymous function types with single params can omit parens
* [Flow] Optional names for object indexer keys
* Add noAnonFunctionType explicitly to state
* Adjust gitattributes as files have been fixed
* Increase test coverage
* Test for error when binding `this` in destructuring pattern
* Ignore coverage of inAsync check in parseAwait - already checked externally
* Ignore coverage of default case in checkPropClash
* Remove unused parameter isAsync from parseParenAndDistinguishExpression
* Ignore coverage of an `else` branch in flowParseTypeParameterDeclaration
* Flow: remove unused parameters to flowParseTypeAnnotatableIdentifier
* Flow: ignore coverage of pass-through throw statement in parseConditional
* Flow: Add test for error on property with type param
* Flow: ignore coverage of pass-through throw statements in parseMaybeAssign, parseArrow
* Add test for error on XML-style comment in module code
* Update test for error on method in object pattern
* Test for error: "Only '=' operator can be used for specifying default value"
* Property variance type annotations for Flow plugin
Non-method properties and indexers of object types, declare class, and
interfaces can be "positive" or "negative." Class fields, but again not
methods, can also have variance.
This PR generalizes the variance annotations for type parameters into a
new node type, and reuses that node for those properties.
The code for object types is reused for interfaces and declare classes.
The changes there are straightfoward.
The code for class fields is reused for object literals, which do not
support variance annotations (currently). This code is a bit sketchy,
because we always parse variance annotations in the `parsePropertyName`
extension, then error in a the subsequent parse phase for object
literals (`parseObjPropValue`) or class methods (`parseClassMethod`).
* Remove bogus unreachable code, clarify variance parsing conditional
* Don't use a new node type for variance annotations
Adding a new node type, specifically changing the TypeParameter node's
variance property to be node-valued, is a breaking change. We might
choose to make this breaking change in a later version.
* s/start/variancePos
Expanding on #150, this allows `unexpected()` to accept the expected token type instead of a message string.
This overload is then used in a couple more places (that independently implement a logic similar to `expect()`'s) to construct an `Unexpected token, expected FOO` message.
I also noticed that there was missing test coverage for builtin types,
so I added a test for that, which includes the newly added type as well
as the other existing types.
* Use browserslist to parse browsers from query.
* Update README.
* Use int values.
* Allow `isPluginRequired` use browserslist queries.
* Fix conflicts during different versions merging.
* Add tests for browserslist queries.
* Early return for getTargets.
* Update README: Describe `browsers` option.
* fix doc [skip ci]
* Move to dependencies [skip ci]
* Remove unused const.
* Use doublequotes for strings.
* Add Caveat section to Readme.md
The Caveat section details some known issues and workaround when targeting specific environments and using specific plugins.
* fixes [skip ci]
Use the data from https://github.com/kangax/compat-table to build the
browser data.
Each Babel plugin is mapped to a list of features in the compatibility
table (in `data/pluginFeatures.js`), and the minimum supporting
version looked up from the compatibility test data. The script builds
the final browser data file in `data/plugins.json`.
* Fix parsing object rest
This makes object-rest-spread behave according to spec and only
allow one rest operator and enforces it to be the last
param in the object.
Also move all object-rest-spread tests to a own folder.
* Show nicer error messages
* Rephrase "assigning/binding to rvalue" error messages with context (#119)
* Fix code style in parser/lval.js
* istanbul ignore some unused branches in parser/lval.js
* Fix code style again in parser/lval.js
* Slightly simplify logic
* Implement ES2016 check for simple parameter list in strict mode
See e.g. ECMA-262 7.0 14.1.2:
> It is a Syntax Error if ContainsUseStrict of FunctionBody is true and
> IsSimpleParameterList of FormalParameters is false.
Similar clauses cover arrow functions, generator functions, methods, and
generator methods, as well as async functions and async arrow functions.
* exact object type annotations for Flow plugin
* Couple tweaks per suggestions
* s/==/===/
* add test for unexpected token in flowObjectType Semicolon
This makes declare class extends behave the same way as in flow
The ast-token after the extends keyword, might be either Identifier or
QualifiedTypeIdentifier
To do that this commits splits the parseGenericType into two functions,
one for parsing genericType and on for qualifiedTypeIdentifier
Flow's "toAssignable" override wasn't calling the inner function,
resulting in the destructuring in an AssignmentPattern not having the
node type changed from ObjectExpression to ObjectPattern, resulting in
"Binding rvalue" thrown from "checkLVal()"
* This removes the exponentiationOperator as it is now in es2016
* Remove from tests
* Remove asyncFunctions and restructure test dirs
* Remove trailingFunctionCommas
We do not clone arrays in lookahead() but comments were added
to leading/trailing arrays during lookahead, leading to leak to the next next() call.
Also extracted parsing of JSXSpreadChild to own parse function.
This commit e6c11a0 (#19) made a big performance regression.
The reason was that parseConditional was always cloning the current state
even if no question mark (potential conditional or flow-optional
token) was at the current position.
Simply checking if questionmark matches the current token solves the problem.
Fixes#62
The cloning caused comments that where added to the original node to be persisted into
the cloned node.
Espree/Acorn does not have any cloning, that's why it is working there.
This change omits comments when cloning, as removing the cloning
causes tests in babel to fail.
The primary goal of this commit is to add the ability to parse type parameter
declarations with defaults, like `type Foo<T = string> = T`. While I was in the
code, I fixed a few small things, like
* Type parameter declarations need 1 or more type parameters.
* The existential type `*` is not a valid type parameter.
* The existential type `*` is a primary type
* The param list for type parameter declarations now consists of
`TypeParameter` nodes
This fixes an issue that comments were added as leading comments
to expressions, which are not immediately folowing the comment.
This was also reported and fixed in espree, and is basically a port to
babylon. eslint/espree#256
this also fixes an issue in babel-eslint with certain rules babel/babel-eslint#289
The fix includes creating a new method on the parser called `parseArrow`.
This new function by default only checks if current position matches an
arrow. If it does returns the `node` otherwise `undefined`.
The flow plugin can then extend this function and correctly parse the typeAnnotation
and add it to the node.
With this change, in the flow plugin there is no need anymore to extend
`parseParenAndDistinguishExpression` and the arrow handling in `parseParenItem`
could also be removed, because it is all handled now in `parseArrow`.
Some existing tests were failing, because `extra->parentesized` is now missing,
but this is correct as it is now inline with parsing without flow annotation. No extra
is added for arrow function without type annotations.
In the expression-parser `this.next()` was replaced by a more specific
`this.expect(tt.parenL)`.
This syntax allows you to specify whether a type variable can appear in
a covariant or contravariant position, and is super useful for, say,
Promise.
Right now this is hacked in jankily, but in the next major release we
should stop using Identifier nodes for type parameters.
An interface export is just like a type export. In fact, it's a syntax affordance which makes the following equivalent:
```javascript
interface I_ { ... }
export type I = I_;
```
```javascript
export interface I { ... }
```
See facebook/flow#1145
This has been a feature in Flow for a long time (couldn't easily find a
specific commit adding this). Interfaces are basically undocumented, though, so
it's easy to see how this was missed.
For example:
var foo = function () {
"use strict";
"use strict";
// there is inside of strict mode,
// so `0123` (octal number) occurs a syntax error.
};
// there is outside of strict mode,
0123; // so left is valid syntax.
// however:
// SyntaxError: Invalid number (8:0)
I fixed it and add the test case.
Removed `@flow` annotation from files that don't actually pass Flow check at the moment. These will be added back file by file once the files are properly converted to use Flow.
Closes#3064
I'm extremely stupid and didn't commit as I go. To anyone reading this
I'm extremely sorry. A lot of these changes are very broad and I plan on
releasing Babel 6.0.0 today live on stage at Ember Camp London so I'm
afraid I couldn't wait. If you're ever in London I'll buy you a beer
(or assorted beverage!) to make up for it, also I'll kiss your feet and
give you a back massage, maybe.
- The visitor keys for `ObjectTypeAnnotation`s were incorrect so those nodes weren't being traversed so comments weren't attached for them.
- The type parser wasn't eating the semicolons for the nodes so the `end` location of each of the type properties wasn't accurate which threw off the code generation newline algorithm.
- Type properties hadn't been given the `UserWhitespacable` alias.
This completely changes the interface, and removes most of the complexity
in the old tokenizer interface (jump-to-position was removed, since it is
all kinds of unreliable given the new tokenizer context system).
Makes almost everything in acorn.js a method of this object.
Performance is not significantly affected on a modern V8. Makes the
code reentrant and allows us to more easily expose more methods
externally in the future.
On the other hand, the proliferation of `this.` is unfortunate.
Now identifiers and strings even with escaped chars are read
in optimized way by reading entire chunks delimited by escape
chars (and not bailing to deopt mode on first one).
Avoid need for:
* extra `templates` array in favor of new `tokContext`;
* special location handling for first & last template elements;
* separate `_templateContinued` token in favor of same `_template`.
Adds:
* token types for backQuote and dollarBraceL instead of skipping them
so they can be handled (i.e. highlighted differently).
* Parsing assignables without extra transform step when possible (speed-up).
* Added support for shorthand defaults in such certain contexts (issue #181).
Conflicts:
acorn.js
acorn_loose.js
* Parsing assignables without extra transform step when possible (speed-up).
* Added support for shorthand defaults in such certain contexts (issue #181).
Define Program node extent to be the whole program, make
both parser and the tests conform to this.
Fix a bunch of bugs in the loose parser's handling of corner
cases.
Issue #151
* Added support for acorn_loose and grouped log to web-driver.
* Removed unused copy-pasted `parseTemplate` from loose parser.
* Throw non-SyntaxError errors immediately (as those are generic).
* Tokens are now instances of single exported constructor Token.
* Token objects are compatible with Esprima (only `type` format is different).
* Added token.loc in format of node.loc (Mozilla).
* Deprecated token.startLoc & token.endLoc.
* Updated comment generation example.
Also added ability to pass arrays in `onToken`/`onComment` where
tokens/comments will be collected in Esprima's format so you can
simply pass those arrays to `escodegen.attachComments`.
Updated docs and comment attachment example.
* Fixed `onToken` & `tokenize` to return `startLoc` & `endLoc`
in token object only when `options.locations` is `true`.
* Fixed `onToken` tests.
* Added example for generating comments with escodegen.
Possible dev relic.
readToken_slash currently does not have any arguments and does not appear to look at arguments. All existing tests pass after removal of extraneous argument while calling readToken_slash.
http://wiki.ecmascript.org/doku.php?id=harmony:rest_parameters
The final parameter to a function is a rest parameter if it is
prefixed by "...". FunctionExpression and FunctionDeclaration
nodes have a new "rest" property that is null if there is no
rest parameter, or contains an Identifer for the parameter.
https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API#Functions
Implemented by adding a new token, `_ellipsis`, which consists of
three dots. Modified the body of parseFunction to allow a single
rest parameter at the end of an argument list. Both the token and
the rest parameter require `options.ecmaVersion` >= 6, otherwise
three dots are tokenized as three dots.
Before this the ast produced by parse_dammit crashed in the following
code, as Uglify correctly noticed that f."" is invalid.
sample = 'f."';
loose = require('acorn/acorn_loose');
uglify = require('uglify-js');
out = new uglify.OutputStream();
ast = loose.parse_dammit(sample);
ast = uglify.AST_Node.from_mozilla_ast(ast);
ast.print(out);
// TypeError: Cannot call method 'toString' of undefined
// member_exp.computed = false && member_exp.property == ""
console.log(out.toString());
After this the round-tripped AST looks like: `t.✖;"";`, which is
consistent with how `foo.{` is parsed.
I also considered making it parse as t[""], but as this only turns up in
the wild when people try to use multiline strings, I felt it was better
to be obviously wrong.
Both readString and skipLineComment considered 8232/8233 as eol, but skipSpace itself would not increment the line counters if they were found.
Previously 8232/8233 were listed in nonASCIIwhitespace, but since that is only used within skipSpace and those values are checked separately, they could be removed from nonASCIIwhitespace.
Just being consistent.
In every other place where a between comparison is done, the lower limit is on the left. It's a whole lot easier to see it's a between comparison when the limits are in order.
When the continued expression sat on column 1 after a non-whitespace char,
the heuristic would consider it the start of the line, even though it wasn't.
Issue marijnh/tern#141
Dedented tokens should only end an expression if they are actually the first
token on the line.
This to prevent code like this from going wrong:
x = (function(..) {
blah();
})(); // <-- indented same as start of expression
My initial idea, that client code would constantly need to access the individual
walker functions directly, isn't actually the case. This prevents unnecessary copying
of other interface functions into walkers.
When setting the .prototype.source the sourceFile variable is undefined, and
setting the sourceFile option doesn't change the .source property on the
prototype anymore.
By setting the .source property inside the node_loc_t constructor, the correct
sourceFile is set in the loc object.
In the generated ast, "null"/"true"/"false" are "Literal" nodes.
As every "Literal" node has a 'raw' property,
When i am doing something with the ast using python,
the 3 "Literal"s caused some problem.
make the 3 "Literal"s have 'raw' property.
This way, composite expressions that they are part of won't get bogus
unsyntactic substrings as their range (i.e. in '(1)+1', the binop expression
would span '1)+1').
Closes#14
- if `program` is given, it'll be used as the toplevel node, instead of
creating a new node, and statements will be added to its body
- if `sourceFile` is given and `locations` is ON, it'll set the `source`
property in every node's `loc`.
Checking for `\r\n?` is redundant with the `|[\n\r\u2028\u2029]`, better straighten the regexp and check for `\r\n|[\n\r\u2028\u2029]`. This might even be a itsy bitsty bit faster.
For any issue references: Add a comma-separated list of a [closing word](https://help.github.com/articles/closing-issues-via-commit-messages/) followed by the ticket number fixed by the PR
For issue references: Add a comma-separated list of a [closing word](https://help.github.com/articles/closing-issues-via-commit-messages/) followed by the ticket number fixed by the PR. It should be underlined in the preview if done correctly.
-->
| Q | A <!--(yes/no) -->
| Q | A <!--(Can use an emoji 👍) -->
| ------------------------ | ---
| Patch: Bug Fix? |
| Major: Breaking Change? |
| Minor: New Feature? |
| Deprecations? |
| Spec Compliancy? |
| Tests Added/Pass? |
| Fixed Tickets | `Fixes #1, Fixes #2` <!-- rm the quotes to link the issues -->
| Fixed Issues? | `Fixes #1, Fixes #2` <!-- remove the (`) quotes to link the issues -->
| Patch: Bug Fix? |
| Major: Breaking Change? |
| Minor: New Feature? |
| Tests Added + Pass? | Yes
| Documentation PR | <!-- If so, add `[skip ci]` to your commit message to skip CI -->
| Any Dependency Changes? |
| License | MIT
| Doc PR | <!-- if yes, add `[skip ci]` to your commit message to skip CI builds -->
| Dependency Changes |
<!-- Describe your changes below in as much detail as possible -->
* [#6081](https://github.com/babel/babel/pull/6081) Flow opaque type 6.x backport. ([@jbrown215](https://github.com/jbrown215))
#### :rocket: New Feature
*`babel-cli`
* [#5796](https://github.com/babel/babel/pull/5796) Allow --inspect-brk option to be used with babel-node [6.x backport]. ([@noinkling](https://github.com/noinkling))
* [#5780](https://github.com/babel/babel/pull/5780) Backport support for createReactClass with transform-react-display-name. ([@kentor](https://github.com/kentor))
* [#5554](https://github.com/babel/babel/pull/5554) Updated transform-react-display-name for createReactClass addon. ([@bvaughn](https://github.com/bvaughn))
* [#5093](https://github.com/babel/babel/pull/5093) Ensure array is always copied during destructure. ([@existentialism](https://github.com/existentialism))
@@ -293,7 +381,7 @@ const arr = [1, 2, 3]
assign(arr,1,42)
console.log(arr)// [1, 2, 3]
```
*`babel-plugin-transform-es2015-function-name`
* [#5008](https://github.com/babel/babel/pull/5008) Don't try to visit ArrowFunctionExpression, they cannot be named. ([@Kovensky](https://github.com/Kovensky))
@@ -308,9 +396,9 @@ Output
```js
exportconstx=({x})=>x;
exportconsty=functiony(){};
exportconsty=functiony(){};
```
*`babel-types`
* [#5068](https://github.com/babel/babel/pull/5068) Fix getBindingIdentifiers in babel-types. ([@rtsao](https://github.com/rtsao))
*`babel-cli`
@@ -460,7 +548,7 @@ Will still error with `Spread children are not supported.`
@@ -480,12 +568,12 @@ When block scoped variables caused the block to be wrapped in a closure, the var
functionrender(flag){
if(flag){
letbar="bar";
[].map(()=>bar);
return<foobar={bar}/>;
}
returnnull;
}
```
@@ -526,7 +614,7 @@ for (let a of b) {
* [#4999](https://github.com/babel/babel/pull/4999) babel-helper-transform-fixture-test-runner: pass require as a global. ([@hzoo](https://github.com/hzoo))
Allows running `require()` in exec.js tests like for [babel/babel-preset-env#95](https://github.com/babel/babel-preset-env/pull/95)
* Other
* [#5005](https://github.com/babel/babel/pull/5005) internal: don't run watch with the test env (skip building with code …. ([@hzoo](https://github.com/hzoo))
* [#4901](https://github.com/babel/babel/pull/4901) Only base async fn arity on non-default/non-rest params - Closes [#4891](https://github.com/babel/babel/issues/4891). ([@loganfsmyth](https://github.com/loganfsmyth))
@@ -660,7 +748,7 @@ console.log(foo.length) // 0
constasyncFoo=async(...args)=>{}
console.log(asyncFoo.length)// 0
```
*`babel-generator`, `babel-types`
* [#4945](https://github.com/babel/babel/pull/4945) Add `babel-generator` support for `Import`. ([@TheLarkInn](https://github.com/TheLarkInn))
* [#3456](https://github.com/babel/babel/pull/3456) Use the real sourcemap API and handle input sourcemaps - Fixes [#7259](https://github.com/babel/babel/issues/7259). ([@loganfsmyth](https://github.com/loganfsmyth))
* [#4507](https://github.com/babel/babel/pull/4507) Only set options in cli if different from default. ([@danez](https://github.com/danez))
Fix an issue with defaults not being overidden. This was causing options like `comments: false` not to work correctly.
* [#4508](https://github.com/babel/babel/pull/4508) Support custom ports for V8 --inspect. ([@andykant](https://github.com/andykant))
@@ -1730,7 +1818,7 @@ We noticed that we can not make this optimizations if there are function calls o
// was tranforming to
x = a();
y = obj.x;
// now transforms to
// now transforms to
var _ref = [a(), obj.x];
x = _ref[0];
y = _ref[1];
@@ -1796,7 +1884,7 @@ Cleanup tests, remove various unused dependencies, do not run CI with only readm
#### Commiters: 20
First PRs!
- Alberto Piai ([brainlock](https://github.com/brainlock))
- Alberto Piai ([brainlock](https://github.com/brainlock))
- Andy Kant ([andykant](https://github.com/andykant))
@@ -2117,7 +2205,7 @@ Can be `false` to not transform modules, or one of `["amd", "umd", "systemjs", "
## v6.11.5 (2016-07-23)
Thanks to Rob Eisenberg ([EisenbergEffect](https://github.com/EisenbergEffect)), Keyan Zhang ([keyanzhang](https://github.com/keyanzhang)), Rolf Timmermans ([rolftimmermans](https://github.com/rolftimmermans)), Thomas Grainger ([graingert](https://github.com/graingert)),
Thanks to Rob Eisenberg ([EisenbergEffect](https://github.com/EisenbergEffect)), Keyan Zhang ([keyanzhang](https://github.com/keyanzhang)), Rolf Timmermans ([rolftimmermans](https://github.com/rolftimmermans)), Thomas Grainger ([graingert](https://github.com/graingert)),
we have few fixes: fix `babel-register` file paths on error, infer class name for classes with class properties, fix `export *` to account for previously compiled modules.
@@ -2165,7 +2253,7 @@ In this release among other things are some more optimizations for babel-generat
## v6.11.3 (2016-07-13)
The main fix is @loganfsmyth's changes of some parts in babel-generator in [#3565](https://github.com/babel/babel/pull/3565) to fix issues with exponential code generation times in certain cases.
The main fix is @loganfsmyth's changes of some parts in babel-generator in [#3565](https://github.com/babel/babel/pull/3565) to fix issues with exponential code generation times in certain cases.
# NOTE: DO NOT OPEN ISSUES FOR QUESTIONS AND SUPPORT. SEE THE README FOR MORE INFO.
----
<p align="center" class="toc">
@@ -19,18 +17,20 @@
# Contributing
> Before contributing, please read our [code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
Contributions are always welcome, no matter how large or small.
Contributions are always welcome, no matter how large or small. Before
contributing, please read the
[code of conduct](https://github.com/babel/babel/blob/master/CODE_OF_CONDUCT.md).
## Not sure where to start?
- If you aren't just making a documentation change, you'll probably want to learn a bit about a few topics.
- [ASTs](https://en.wikipedia.org/wiki/Abstract_syntax_tree) (Abstract Syntax Tree): The Babel AST [spec](https://github.com/babel/babylon/blob/master/ast/spec.md) is a bit different from [ESTree](https://github.com/estree/estree). The differences are listed [here](https://github.com/babel/babylon#output).
- [ASTs](https://en.wikipedia.org/wiki/Abstract_syntax_tree) (Abstract Syntax Tree): The Babel AST [spec](https://github.com/babel/babel/tree/master/packages/babylon/blob/master/ast/spec.md) is a bit different from [ESTree](https://github.com/estree/estree). The differences are listed [here](https://github.com/babel/babel/tree/master/packages/babylon#output).
- Check out [`/doc`](https://github.com/babel/babel/tree/master/doc) for information about Babel's internals
- Check out [the Babel Plugin Handbook](https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#babel-plugin-handbook) - core plugins are written the same way as any other plugin!
- Check out [AST Explorer](http://astexplorer.net/#/scUfOmVOG5) to learn more about ASTs or make your own plugin in the browser
- When you feel ready to jump into the Babel source code, a good place to start is to look for issues tagged with [help-wanted](https://github.com/babel/babel/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22) and/or [beginner-friendly](https://github.com/babel/babel/issues?q=is%3Aissue+is%3Aopen+label%3A%22beginner-friendly%22).
- When you feel ready to jump into the Babel source code, a good place to start is to look for issues tagged with [helpwanted](https://github.com/babel/babel/labels/help%20wanted) and/or [good first issue](https://github.com/babel/babel/labels/good%20first%20issue).
- Follow along with what we are working on by joining our Slack, following our announcements on [Twitter](https://twitter.com/babeljs), and reading (or participating!) in our [meeting notes](https://github.com/babel/notes).
- Check out our [website](http://babeljs.io/) and the [repo](https://github.com/babel/website)
## Chat
@@ -40,11 +40,9 @@ Feel free to check out the `#discussion`/`#development` channels on our [Slack](
**Note:** Versions `< 5.1.10` can't be built.
Babel is built for Node.js 4 and up but we develop using Node.js 6. Make sure you are on npm 3.
Babel is built for Node 4 and up but we develop using Node 8 and yarn. You can check this with `node -v`.
You can check this with `node -v` and `npm -v`.
In addition, make sure that Yarn is installed.
Make sure that Yarn is installed with version >= `0.28.0`.
Installation instructions can be found here: https://yarnpkg.com/en/docs/install.
### Setup
@@ -114,12 +112,25 @@ To run tests for a specific package in [packages](https://github.com/babel/babel
$ TEST_ONLY=babel-cli make test
```
`TEST_ONLY` will also match substrings of the package name:
```sh
# Run tests for the babel-plugin-transform-classes package.
$ TEST_ONLY=es2015-class make test
```
Use the `TEST_GREP` variable to run a subset of tests by name:
```sh
$ TEST_GREP=transformation make test
```
Substitute spaces for hyphens and forward slashes when targeting specific test names:
```sh
$ TEST_GREP="arrow functions destructuring parameters" make test
```
To enable the Node.js debugger added in v6.3.0, set the `TEST_DEBUG` environment variable:
```sh
@@ -135,18 +146,17 @@ $ BABEL_ENV=cov make build
$ ./scripts/test-cov.sh
```
#### Troubleshooting Tests
In case you're not able to reproduce an error on CI locally, it may be due to
In case you're not able to reproduce an error on CI locally, it may be due to
- Node Version: Travis CI runs the tests against all major node versions. If your tests use JavaScript features unsupported by lower versions of node, then use [minNodeVersion option](#writing-tests) in options.json.
- Timeout: Check the CI log and if the only errors are timeout errors and you are sure that it's not related to the changes you made, ask someone in the slack channel to trigger rebuild on the CI build and it might be resolved
In case you're locally getting errors which are not on the CI, it may be due to
- Updates in Dependencies: Make sure you run `make bootstrap` before you run `make build` or `make watch` before you run the tests.
### Writing tests
Most packages in [`/packages`](https://github.com/babel/babel/tree/master/packages) have a `test` folder, however some tests might be in other packages or in [`/packages/babel-core`](https://github.com/babel/babel/tree/master/packages/babel-core/test/fixtures).
@@ -160,7 +170,7 @@ For example, in [`babel-plugin-transform-exponentiation-operator/test`](https://
- There is an `index.js` file. It imports our [test helper](https://github.com/babel/babel/tree/master/packages/babel-helper-plugin-test-runner). (You don't have to worry about this).
- There can be multiple folders under [`/fixtures`](https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures)
- There is an [`options.json`](https://github.com/babel/babel/blob/master/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/exponentian-operator/options.json) file whose function is similar to a `.babelrc` file, allowing you to pass in the plugins and settings you need for your tests.
- For this test, we only need the relevant plugin, so it's just `{ "plugins": ["transform-exponentiation-operator"] }`.
- For this test, we only need the relevant plugin, so it's just `{ "plugins": ["@babel/transform-exponentiation-operator"] }`.
- If necessary, you can have an `options.json` with different options in each subfolder.
- In each subfolder, you can organize your directory structure by categories of tests. (Example: these folders can be named after the feature you are testing or can reference the issue number they fix)
@@ -195,8 +205,8 @@ If you need to check for an error that is thrown you can add to the `options.jso
"throws":"@babel/proposal-object-rest-spread currently only accepts a boolean option for useBuiltIns (defaults to false)"
}
```
@@ -209,20 +219,33 @@ If the test requires a minimum Node version, you can add `minNodeVersion` (must
}
```
#### `babylon`
Writing tests for Babylon is very
similar to the other packages.
Inside the `packages/babylon/tests/fixtures` folder are categories/groupings of test fixtures (es2015, flow,
etc.). To add a test, create a folder under one of these groupings (or create a new one) with a
descriptive name, and add the following:
* Create an `actual.js` file that contains the code you want Babylon to parse.
* Add an `expected.json` file with the expected parser output. For added convenience, if there is no `expected.json` present, the test runner will generate one for you.
#### Bootstrapping expected output
For both `babel-plugin-x` and `babylon`, you can easily generate an `expected.js`/`expected.json` automatically by just providing `actual.js` and running the tests as you usually would.
```
// Example
- babylon
- test
- fixtures
- comments
- basic
- block-trailing-comment
- actual.js
- expected.json (will be generated if not created)
- packages
- babylon
- test
- fixtures
- comments
- basic
- block-trailing-comment
- actual.js
- expected.json (will be generated if not created)
```
### Debugging code
@@ -261,9 +284,21 @@ To start the debugging in Chrome DevTools, open the given URL.
The debugger starts at the first executed line of code, which is Mocha's first line by default.
Click _Resume script execution_ <img src="https://i.imgur.com/TmYBn9d.png" alt="Resume script execution button." width="16"> to jump to the set breakpoint.
Note that the code shown in Chrome DevTools is compiled code and therefore differs.
- Create a new issue that describes the proposal (ex: [#538](https://github.com/babel/babylon/issues/538)). Include any relevant information like proposal repo/author, examples, parsing approaches, meeting notes, presentation slides, and more.
- The pull request should include:
- [ ] An update to the [plugins](https://github.com/babel/babel/tree/master/packages/babylon#plugins) part of the readme. Add a new entry to that list for the new plugin flag (and link to the proposal)
- [ ] If any new nodes or modifications need to be added to the AST, update [ast/spec.md](https://github.com/babel/babel/bloc/master/packages/babylon/ast/spec.md)
- [ ] Make sure you use the `this.hasPlugin("plugin-name-here")` check in Babylon so that your new plugin code only runs when that flag is turned on (not default behavior)
- [ ] Add failing/passing tests according to spec behavior
- Compiler environment support ([doc/design/compiler-environment-support.md](https://github.com/babel/babel/blob/master/doc/design/compiler-environment-support.md))
Babel is a community-driven tool that helps you write code in the latest version of JavaScript.
Babel is community-driven and thus mostly maintained by a group of [volunteers](https://babeljs.io/team). It has a lot of [companies and projects](http://babeljs.io/users) using it but almost no sponsors/people funded to work on it. If you'd like to help maintain the future of the project, please consider:
When your supported environments don't support certain features natively, Babel will help you compile those features down to a supported version.
- Giving developer time on the project. (Message us on [Twitter](https://twitter.com/babeljs) or [Slack](slack.babeljs.io))
- [Giving funds by becoming a backer/sponsor on OpenCollective](https://opencollective.com/babel)
## Intro
Babel is a tool that helps you write code in the latest version of JavaScript. When your supported environments don't support certain features natively, Babel will help you compile those features down to a supported version.
**In**
@@ -41,173 +48,45 @@ When your supported environments don't support certain features natively, Babel
});
```
Try it out at our [REPL](https://babeljs.io/repl/#?babili=false&evaluate=true&lineWrap=false&presets=latest&code=%5B1%2C2%2C3%5D.map(n%20%3D%3E%20n%20%2B%201)%3B&experimental=true&loose=true&spec=false&playground=false&stage=0) and follow us at [@babeljs](https://twitter.com/babeljs).
Try it out at our [REPL](https://babeljs.io/repl/build/master#?code_lz=NoRgNATGDMC6B0BbAhgBwBQDsAEBeAfNjgNTYgCUA3EA&lineWrap=true&presets=es2015%2Ces2016%2Ces2017&version=7.0.0-beta.2).
- [FAQ](#faq)
- [Packages](#packages)
- [Core Packages](#core-packages)
- [Other](#other)
- [Presets](#presets)
- [Plugins](#plugins)
- [Transform Plugins](#transform-plugins)
- [Syntax Plugins](#syntax-plugins)
- [Misc Packages](#misc-packages)
- [Team](#team)
- [Backers](#backers)
- [Sponsors](#sponsors)
- [License](#license)
# FAQ
## FAQ
## Docs?
### Who maintains Babel?
Check out our website: [babeljs.io](http://babeljs.io/)
Mostly a handful of volunteers! Please check out our [team page](https://babeljs.io/team)!
## Looking for support?
### Looking for support?
For questions and support please visit our [discussion forum](https://discuss.babeljs.io/), sign up for our [Slack community](https://slack.babeljs.io/), or [StackOverflow](http://stackoverflow.com/questions/tagged/babeljs).
For questions and support please visit join our [Slack Community](https://slack.babeljs.io/), ask a question on [StackOverflow](http://stackoverflow.com/questions/tagged/babeljs), or ping us on [Twitter](https://twitter.com/babeljs/).
## Want to report a bug or request a feature?
### Where are the docs?
Bugs and feature requests can be posted at https://github.com/babel/babel/issues.
Check out our website: [babeljs.io](http://babeljs.io/), and report issues/features at [babel/website](https://github.com/babel/website/issues).
> We've moved our issues from phabricator back to github issues!
### Want to report a bug or request a feature?
Former phabricator issue URLs now automatically redirect to their corresponding Github issue:
Please read through our [CONTRIBUTING.md](https://github.com/babel/babel/blob/master/CONTRIBUTING.md) and fill out the issue template at [babel/issues](https://github.com/babel/babel/issues)!
https://phabricator.babeljs.io/T2168 mostly corresponds to https://github.com/babel/babel/issues/2168.
### Want to contribute to Babel?
## Want to report an issue with [babeljs.io](https://babeljs.io) (the website)?
Check out our [CONTRIBUTING.md](https://github.com/babel/babel/blob/master/CONTRIBUTING.md) to get started with setting up the repo.
For documentation and website issues please visit the [babel/babel.github.io](https://github.com/babel/babel.github.io) repo.
- If you have already joined Slack, join our [#development](https://babeljs.slack.com/messages/development) channel and say hi!
- Check out the issues with the [good first issue](https://github.com/babel/babel/labels/good%20first%20issue) and [help wanted](https://github.com/babel/babel/labels/help%20wanted) label. We suggest also looking at the closed ones to get a sense of the kinds of issues you can tackle.
- Our progress on TC39 proposals: [babel/proposals](https://github.com/babel/proposals)
## Want to contribute to Babel?
### How is the repo structured?
Check out our [CONTRIBUTING.md](https://github.com/babel/babel/blob/master/CONTRIBUTING.md). If you have already joined Slack, join our [#development](https://babeljs.slack.com/messages/development) channel!
The Babel repo is managed as a [monorepo](https://github.com/babel/babel/blob/master/doc/design/monorepo.md) that is composed of many [npm packages](/packages#readme).
You can also start by checking out the issues with the [help-wanted](https://github.com/babel/babel/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22) label.
[`babel-core`](/packages/babel-core) is the Babel compiler itself; it exposes the `babel.transform` method, where `transformedCode = transform(src).code`.
The compiler can be broken down into 3 parts:
- The parser: [`babylon`](https://github.com/babel/babylon) (moved to a separate repo and versioned independently)
- The transformer[s]: All the plugins/presets
- These all use [`babel-traverse`](/packages/babel-traverse) to traverse through the AST
- The generator: [`babel-generator`](/packages/babel-generator)
Check out the [`babel-handbook`](https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#introduction) for more information on this.
- [`babel-cli`](/packages/babel-cli) is the CLI tool that runs `babel-core` and helps with outputting to a directory, a file, stdout and more (also includes `babel-node`). Check out the [docs](https://babeljs.io/docs/usage/cli/).
- [`babel-types`](/packages/babel-types) is used to validate, build and change AST nodes.
- [`babel-polyfill`](/packages/babel-polyfill) is [literally a wrapper](https://github.com/babel/babel/blob/master/packages/babel-polyfill/src/index.js) around [`core-js`](https://github.com/zloirock/core-js) and [regenerator-runtime](https://github.com/facebook/regenerator/tree/master/packages/regenerator-runtime). Check out the [docs](https://babeljs.io/docs/usage/polyfill/).
- [`babel-runtime`](/packages/babel-runtime) is similar to the polyfill except that it doesn't modify the global scope and is to be used with [`babel-plugin-transform-runtime`](/packages/babel-plugin-transform-runtime) (usually in library/plugin code). Check out the [docs](https://babeljs.io/docs/plugins/transform-runtime/).
- [`babel-register`](/packages/babel-register) is a way to automatically compile files with Babel on the fly by binding to Node.js `require`. Check out the [docs](http://babeljs.io/docs/usage/require/).
- [`babel-template`](/packages/babel-template) is a helper function that allows constructing AST nodes from a string presentation of the code; this eliminates the tedium of using `babel-types` for building AST nodes.
- [`babel-helpers`](/packages/babel-helpers) is a set of pre-made `babel-template` functions that are used in some Babel plugins.
- [`babel-code-frame`](/packages/babel-code-frame) is a standalone package used to generate errors that print the source code and point to error locations.
After Babel 6, the default transforms were removed; if you don't specify any plugins/presets, Babel will just return the original source code.
The transformer[s] used in Babel are the independent pieces of code that transform specific things. For example: the [`es2015-arrow-functions`](/packages/babel-plugin-transform-es2015-arrow-functions) transform specifically changes arrow functions into regular functions. A preset is simply an array of plugins that make it easier to run a whole a set of transforms without specifying each one manually.
| Package | Version | Dependencies | Description |
|--------|-------|------------|---|
| [`babel-preset-env`](https://github.com/babel/babel-preset-env) | [](https://www.npmjs.com/package/babel-preset-env) | [](https://david-dm.org/babel/babel-preset-env) | automatically determines plugins and polyfills you need based on your supported environments |
> You can find community maintained presets on [npm](https://www.npmjs.com/search?q=babel-preset)
### [Plugins](http://babeljs.io/docs/plugins)
Plugins are the heart of Babel and what make it work.
> You can find community plugins on [npm](https://www.npmjs.com/search?q=babel-plugin).
#### Transform Plugins
There are many kinds of plugins: ones that convert ES6/ES2015 to ES5, transform to ES3, minification, JSX, flow, experimental features, and more. Check out our [website for more](http://babeljs.io/docs/plugins/#transform-plugins).
#### Syntax Plugins
These just enable the transform plugins to be able to parse certain features (the transform plugins already include the syntax plugins so you don't need both): `babel-plugin-syntax-x`. Check out our [website for more](http://babeljs.io/docs/plugins/#syntax-plugins).
### Helpers
These are mostly for internal use in various plugins: `babel-helper-x`.
The [AST specification](https://github.com/babel/babylon/blob/master/ast/spec.md) has been moved to the Babylon repo, `babel/babylon`.
The [AST specification](https://github.com/babel/babel/blob/master/packages/babylon/ast/spec.md) has been moved to the Babylon package, `packages/babylon`.
@@ -21,7 +21,7 @@ This is quite taboo but let's look at the pros and cons:
* Codebase looks more intimidating.
* Repo is bigger in size.
*Lower ranking in [npms](https://npms.io/) results. At least until [npms-io/npms-analyzer#83](https://github.com/npms-io/npms-analyzer/issues/83) is fixed.
*[Can't `npm install` modules directly from GitHub](https://github.com/npm/npm/issues/2974)
- Update compat table to fix two small issues ([#445](https://github.com/babel/babel-preset-env/pull/445)) (@danez)
ES2015 destructuring is not fully supported in Edge 15 and the polyfill required again. `es6.math.imul` is supported on Android as of version 4.4
- Add polyfills for ES6 static Object methods ([#441](https://github.com/babel/babel-preset-env/pull/441)) (@danez)
Functions such as `Object.keys`, `Object.freeze`, ... do already exist in ES5, but their behaviour changed in ES2015. `babel-preset-env` with `builtIns: true` now adds the core-js polyfills for this methods if the browser only supports the ES5 variant of the method (like IE11 for example)
- Normalize module format of plugins/built-ins data ([#376](https://github.com/babel/babel-preset-env/pull/376)) (@rtsao)
## v1.6.0 (2017-07-04)
### :rocket: New Feature
- Bump compat-table for node8 support ([#363](https://github.com/babel/babel-preset-env/pull/363)) (@existentialism)
We updated our mappings to support native trailing function commas and string paddings in Node.js 8+.
### :bug: Bug Fix
- Handle `chromeandroid` browserslist value ([#367](https://github.com/babel/babel-preset-env/pull/367)) (@yavorsky)
We added support for using browserslist's `chromeandroid` in `targets`.
Our plugin data was missing a mapping for the `transform-duplicate-keys` plugin which caused it to never be included. (s/o to @Timer for the report!)
### :memo: Documentation
- Clarify reasons for the uglify option in README.md ([#188](https://github.com/babel/babel-preset-env/pull/188)) (@mikegreiling)
## v1.2.0 (2017-03-03)
### :rocket: New Feature
- Add uglify as a target ([#178](https://github.com/babel/babel-preset-env/pull/178)) (@yavorsky)
Support for `uglify` as a target is now available! This will enable all plugins and, as a result, fully compiles your code to ES5. Note, that useBuiltIns will work as before, and only the polyfills that your other target(s) need will be included.
```json
{
"presets":[
["env",{
"targets":{
"chrome":55,
"uglify":true
},
"useBuiltIns":true,
"modules":false
}]
]
}
```
### :bug: Bug Fix
- Respect older versions in invert equals map ([#180](https://github.com/babel/babel-preset-env/pull/180)) (@danez)
Fixes a number of bugs that caused some incorrect and/or missing environment data when parsing `compat-table`.
## v1.1.11 (2017-03-01)
This release primarily upgrades `compat-table`, which adds support for async on Node 7.6!
- Add electron version exception test ([#176](https://github.com/babel/babel-preset-env/pull/176)) (@existentialism)
## v1.1.10 (2017-02-24)
### :bug: Bug Fix
- Drop use of lodash/intersection from checkDuplicateIncludeExcludes ([#173](https://github.com/babel/babel-preset-env/pull/173)) (@existentialism)
## v1.1.9 (2017-02-24)
### :bug: Bug Fix
- Add tests for debug output ([#156](https://github.com/babel/babel-preset-env/pull/156)) (@existentialism)
Since we've (mostly @yavorsky) have fixed a number of bugs recently with the `debug` option output, we added the ability to assert stdout matches what we expect. Read the updated [CONTRIBUTING.md](https://github.com/babel/babel-preset-env/blob/master/CONTRIBUTING.md#testing-the-debug-option) for more info.
- Update compat-table, build data ([#135](https://github.com/babel/babel-preset-env/pull/135)) (@hzoo)
## v1.1.8 (2017-01-10)
### :bug: Bug Fix
- Debug: Transformations before logs. ([#128](https://github.com/babel/babel-preset-env/pull/128)) (@yavorsky)
Makes sure that all transformations on `targets` (such as `exclude`/`include`) are run before logging out with the `debug` option. Fixes ([#127](https://github.com/babel/babel-preset-env/issues/127)).
The new `exclude`/`include` options weren't working correctly for built-ins. ([#102](https://github.com/babel/babel-preset-env/pull/102)).
Also fixes an issue with debug option.
## v1.1.1 (2016-12-13)
### :bug: Bug Fix
Regression with the previous release due to using `Object.values` (ES2017). This wasn't caught because we are using babel-register to run tests and includes polyfills so it didn't fail on CI even though we have Node 0.10 as an env. Looking into fixing this to prevent future issues.
## v1.1.0 (2016-12-13)
### :rocket: New Feature
- Add `exclude` option, rename `whitelist` to `include` ([#89](https://github.com/babel/babel-preset-env/pull/89)) (@hzoo)
Example:
```js
{
"presets":[
["env",{
"targets":{
"browsers":["last 2 versions","safari >= 7"]
},
"include":["transform-es2015-arrow-functions"],
"exclude":[
"transform-regenerator",
"transform-async-to-generator",
"map"
],
"useBuiltIns":true
}]
]
}
```
`"exclude": ["transform-regenerator"]` doesn't transform generators and removes `regeneratorRuntime` from being imported.
`"exclude": ["transform-async-to-generator"]` doesn't use the built-in async-to-gen transform so you can use something like [fast-async](https://github.com/MatAtBread/fast-async).
`"exclude": ["map"]` doesn't include the `Map` polyfill if you know you aren't using it in your code (w/ `useBuiltIns`). (We will figure out a way to automatically do this [#84](https://github.com/babel/babel-preset-env/issues/84)).
If you pass a wrong plugin it will error: valid options for `include/exclude` are in [/data/plugin-features.js](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js) and [/data/built-in-features.js](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js) (without the `es6.`)
### :house: Internal
- Optimize result filtration. ([#77](https://github.com/babel/babel-preset-env/pull/77)) (@yavorsky)
- Update eslint config to align with other babel projects ([#79](https://github.com/babel/babel-preset-env/pull/79)) (@baer)
- Update pathnames to avoid uppercase ([#80](https://github.com/babel/babel-preset-env/pull/80)) (@baer)
- Refactor build data for clarity/consistency ([#81](https://github.com/babel/babel-preset-env/pull/81)) (@baer)
- Update linting rules to cover all js ([#82](https://github.com/babel/babel-preset-env/pull/82)) (@baer)
- Cleanup lib before rebuilding ([#87](https://github.com/babel/babel-preset-env/pull/87)) (@baer)
- Move linting dependency to be dev only ([#88](https://github.com/babel/babel-preset-env/pull/88)) (@baer)
A way to apply `babel-preset-env` for polyfills (via `"babel-polyfill"``).
> This option will apply a new Babel plugin that replaces `require("babel-polyfill")` with the individual requires for `babel-polyfill` based on the target environments.
Install
```
npm install babel-polyfill --save
```
In
```js
import "babel-polyfill"; // create an entry js file that contains this
> Also looking to make an easier integration point via Webpack with this method. Please reach out if you have ideas!
---
* Support [Electron](http://electron.atom.io/) ([#55](https://github.com/babel/babel-preset-env/pull/55)) ([@paulcbetts](https://github.com/paulcbetts))
Electron is also an environment, so [Paul went ahead](https://twitter.com/paulcbetts/status/804507070103851008) and added support for this!
> Currently we are manually updating the data in [/data/electron-to-chromium.js](https://github.com/babel/babel-preset-env/blob/master/data/electron-to-chromium.js), but [@kevinsawicki](https://github.com/kevinsawicki) says we could generate the data from [atom-shell/dist/index.json](https://gh-contractor-zcbenz.s3.amazonaws.com/atom-shell/dist/index.json) as well! (Someone should make a PR :smile:)
## v0.0.9 (2016-11-24)
### :rocket: New Feature
* Support Opera ([#48](https://github.com/babel/babel-preset-env/pull/48)) (Henry Zhu)
Was as simple as modifying the chrome version and subtracting 13! (so chrome 54 = opera 41)
```js
{
"presets": [
["env", {
"targets": {
"opera": 41
}
}]
]
}
```
## v0.0.8 (2016-11-16)
### :nail_care: Polish
* Only print the debug info once ([#46](https://github.com/babel/babel-preset-env/pull/46) (Henry Zhu)
When using the `debug` option it was printing the data for each file processed rather than once.
```js
{
"presets": [
["env", {
"debug": true
}]
]
}
```
## v0.0.7 (2016-11-02)
### :rocket: New Feature
* hardcode a current node version option ([#35](https://github.com/babel/babel-preset-env/pull/35)) (Henry Zhu)
In case you want to add `Object.values` which is in ES2017:
Find the relevant feature and subfeature on [compat-table](https://kangax.github.io/compat-table/es2016plus/#test-Object_static_methods_Object.values)
and split it with `/`:
`Object static methods / Object.values`
Find the corresponding module on [core-js](https://github.com/zloirock/core-js/tree/master/modules):
`es7.object.values.js`
Find required ES version in [`built-in-features.js`](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js) and add the new feature:
> A Babel preset that compiles [ES2015+](https://github.com/tc39/proposals/blob/master/finished-proposals.md) down to ES5 by automatically determining the Babel plugins and polyfills you need based on your targeted browser or runtime environments.
```sh
npm install @babel/preset-env --save-dev
```
Without any configuration options, @babel/preset-env behaves exactly the same as @babel/preset-latest (or @babel/preset-es2015, @babel/preset-es2016, and @babel/preset-es2017 together).
```json
{
"presets":["@babel/env"]
}
```
You can also configure it to only include the polyfills and transforms needed for the browsers you support. Compiling only what's needed can make your bundles smaller and your life easier.
This example only includes the polyfills and code transforms needed for the last two versions of each browser, and versions of Safari greater than or equal to 7. We use [browserslist](https://github.com/ai/browserslist) to parse this information, so you can use [any valid query format supported by browserslist](https://github.com/ai/browserslist#queries).
```json
{
"presets":[
["@babel/env",{
"targets":{
"browsers":["last 2 versions","safari >= 7"]
}
}]
]
}
```
Similarly, if you're targeting Node.js instead of the browser, you can configure babel-preset-env to only include the polyfills and transforms necessary for a particular version:
```json
{
"presets":[
["@babel/env",{
"targets":{
"node":"6.10"
}
}]
]
}
```
For convenience, you can use `"node": "current"` to only include the necessary polyfills and transforms for the Node.js version that you use to run Babel:
```json
{
"presets":[
["@babel/env",{
"targets":{
"node":"current"
}
}]
]
}
```
- [How it Works](#how-it-works)
- [Install](#install)
- [Usage](#usage)
- [Options](#options)
- [Examples](#examples)
- [Issues](#issues)
## How it Works
### Determine environment support for ECMAScript features
Use external data such as [`compat-table`](https://github.com/kangax/compat-table) to determine browser support. (We should create PRs there when necessary)
We can periodically run [build-data.js](https://github.com/babel/babel-preset-env/blob/master/scripts/build-data.js) which generates [plugins.json](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json).
### Maintain a mapping between JavaScript features and Babel plugins
> Currently located at [plugin-features.js](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js).
This should be straightforward to do in most cases. There might be cases where plugins should be split up more or certain plugins aren't standalone enough (or impossible to do).
### Support all plugins in Babel that are considered `latest`
> Default behavior without options is the same as `@babel/preset-latest`.
It won't include `stage-x` plugins. env will support all plugins in what we consider the latest version of JavaScript (by matching what we do in [`@babel/preset-latest`](http://babeljs.io/docs/plugins/preset-latest/)).
[Browserslist](https://github.com/ai/browserslist) is a library used to share a supported list of browsers between different front-end tools like [autoprefixer](https://github.com/postcss/autoprefixer), [stylelint](https://stylelint.io/), [eslint-plugin-compat](https://github.com/amilajack/eslint-plugin-compat) and many others.
By default, @babel/preset-env will use [browserslist config sources](https://github.com/ai/browserslist#queries).
For example, to enable only the polyfills and plugins needed for a project targeting *last 2 versions* and *IE10*:
**.babelrc**
```json
{
"presets":[
["@babel/env",{
"useBuiltIns":"entry"
}]
]
}
```
**browserslist**
```
Last 2 versions
IE 10
```
or
**package.json**
```
"browserslist": "last 2 versions, ie 10"
```
Browserslist config will be ignored if: 1) `targets.browsers` was specified 2) or with `ignoreBrowserslistConfig: true` option ([see more](#ignoreBrowserslistConfig)):
#### Targets merging.
1. If [targets.browsers](#targetsbrowsers) is defined - the browserslist config will be ignored. The browsers specified in `targets` will be merged with [any other explicitly defined targets](#targets). If merged, targets defined explicitly will override the same targets received from `targets.browsers`.
2. If [targets.browsers](#targetsbrowsers) is _not_ defined - the program will search browserslist file or `package.json` with `browserslist` field. The search will start from the working directory of the process or from the path specified by the `configPath` option, and go up to the system root. If both a browserslist file and configuration inside a `package.json` are found, an exception will be thrown.
3. If a browserslist config was found and other targets are defined (but not [targets.browsers](#targetsbrowsers)), the targets will be merged in the same way as `targets` defined explicitly with `targets.browsers`.
## Install
With [npm](https://www.npmjs.com):
```sh
npm install --save-dev @babel/preset-env
```
Or [yarn](https://yarnpkg.com):
```sh
yarn add @babel/preset-env --dev
```
## Usage
The default behavior without options runs all transforms (behaves the same as [@babel/preset-latest](https://babeljs.io/docs/plugins/preset-latest/)).
```json
{
"presets":["@babel/env"]
}
```
## Options
For more information on setting options for a preset, refer to the [plugin/preset options](http://babeljs.io/docs/plugins/#plugin-preset-options) documentation.
### `targets`
`{ [string]: number | string }`, defaults to `{}`.
Takes an object of environment versions to support.
Each target environment takes a number or a string (we recommend using a string when specifying minor versions like `node: "6.10"`).
The [data](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json) for this is generated by running the [build-data script](https://github.com/babel/babel-preset-env/blob/master/scripts/build-data.js) which pulls in data from [compat-table](https://kangax.github.io/compat-table).
### `targets.node`
`number | string | "current" | true`
If you want to compile against the current node version, you can specify `"node": true` or `"node": "current"`, which would be the same as `"node": process.versions.node`.
### `targets.browsers`
`Array<string> | string`
A query to select browsers (ex: last 2 versions, > 5%) using [browserslist](https://github.com/ai/browserslist).
Note, browsers' results are overridden by explicit items from `targets`.
### `spec`
`boolean`, defaults to `false`.
Enable more spec compliant, but potentially slower, transformations for any plugins in this preset that support them.
### `loose`
`boolean`, defaults to `false`.
Enable "loose" transformations for any plugins in this preset that allow them.
Enable transformation of ES6 module syntax to another module type.
Setting this to `false` will not transform modules.
### `debug`
`boolean`, defaults to `false`.
Outputs the targets/plugins used and the version specified in [plugin data version](https://github.com/babel/babel-preset-env/blob/master/data/plugins.json) to `console.log`.
### `include`
`Array<string>`, defaults to `[]`.
An array of plugins to always include.
Valid options include any:
- [Babel plugins](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js) - both with (`@babel/plugin-transform-spread`) and without prefix (`transform-spread`) are supported.
- [Built-ins](https://github.com/babel/babel-preset-env/blob/master/data/built-in-features.js), such as `map`, `set`, or `object.assign`.
This option is useful if there is a bug in a native implementation, or a combination of a non-supported feature + a supported one doesn't work.
For example, Node 4 supports native classes but not spread. If `super` is used with a spread argument, then the `transform-classes` transform needs to be `include`d, as it is not possible to transpile a spread with `super` otherwise.
> NOTE: The `include` and `exclude` options _only_ work with the [plugins included with this preset](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js); so, for example, including `proposal-do-expressions` or excluding `proposal-function-bind` will throw errors. To use a plugin _not_ included with this preset, add them to your [config](https://babeljs.io/docs/usage/babelrc/) directly.
### `exclude`
`Array<string>`, defaults to `[]`.
An array of plugins to always exclude/remove.
The possible options are the same as the `include` option.
This option is useful for "blacklisting" a transform like `transform-regenerator` if you don't use generators and don't want to include `regeneratorRuntime` (when using `useBuiltIns`) or for using another plugin like [fast-async](https://github.com/MatAtBread/fast-async) instead of [Babel's async-to-gen](http://babeljs.io/docs/plugins/proposal-async-generator-functions/).
### `useBuiltIns`
`"usage"` | `"entry"` | `false`, defaults to `false`.
A way to apply `@babel/preset-env` for polyfills (via `@babel/polyfill`).
```sh
npm install @babel/polyfill --save
```
#### `useBuiltIns: 'usage'`
Adds specific imports for polyfills when they are used in each file. We take advantage of the fact that a bundler will load the same polyfill only once.
**In**
a.js
```js
vara=newPromise();
```
b.js
```js
varb=newMap();
```
**Out (if environment doesn't support it)**
```js
import"core-js/modules/es6.promise";
vara=newPromise();
```
```js
import"core-js/modules/es6.map";
varb=newMap();
```
**Out (if environment supports it)**
```js
vara=newPromise();
```
```js
varb=newMap();
```
#### `useBuiltIns: 'entry'`
> NOTE: Only use `require("@babel/polyfill");` once in your whole app.
> Multiple imports or requires of `@babel/polyfill` will throw an error since it can cause global collisions and other issues that are hard to trace.
> We recommend creating a single entry file that only contains the `require` statement.
This option enables a new plugin that replaces the statement `import "@babel/polyfill"` or `require("@babel/polyfill")` with individual requires for `@babel/polyfill` based on environment.
**In**
```js
import"@babel/polyfill";
```
**Out (different based on environment)**
```js
import"core-js/modules/es7.string.pad-start";
import"core-js/modules/es7.string.pad-end";
```
#### `useBuiltIns: false`
Don't add polyfills automatically per file, or transform `import "@babel/polyfill"` to individual polyfills.
### `forceAllTransforms`
`boolean`, defaults to `false`.
<p><details>
<summary><b>Example</b></summary>
With Babel 7's .babelrc.js support, you can force all transforms to be run if env is set to `production`.
```js
module.exports = {
presets: [
["@babel/env", {
targets: {
chrome: 59,
edge: 13,
firefox: 50,
},
// for uglifyjs...
forceAllTransforms: process.env === "production"
}],
],
};
```
</details></p>
> NOTE: `targets.uglify` is deprecated and will be removed in the next major in
favor of this.
By default, this preset will run all the transforms needed for the targeted
environment(s). Enable this option if you want to force running _all_
transforms, which is useful if the output will be run through UglifyJS or an
environment that only supports ES5.
> NOTE: Uglify has a work-in-progress "Harmony" branch to address the lack of
ES6 support, but it is not yet stable. You can follow its progress in
[UglifyJS2 issue #448](https://github.com/mishoo/UglifyJS2/issues/448). If you
require an alternative minifier which _does_ support ES6 syntax, we recommend
using [babel-minify](https://github.com/babel/minify).
### `configPath`
`string`, defaults to `process.cwd()`
The starting point where the config search for browserslist will start, and ascend to the system root until found.
### `ignoreBrowserslistConfig`
`boolean`, defaults to `false`
Toggles whether or not [browserslist config sources](https://github.com/ai/browserslist#queries) are used, which includes searching for any browserslist files or referencing the browserslist key inside package.json. This is useful for projects that use a browserslist config for files that won't be compiled with Babel.
### `shippedProposals`
`boolean`, defaults to `false`
Toggles enabling support for builtin/feature proposals that have shipped in browsers. If your target environments have native support for a feature proposal, its matching parser syntax plugin is enabled instead of performing any transform. Note that this _does not_ enable the same transformations as [`@babel/preset-stage3`](https://babeljs.io/docs/plugins/preset-stage-3/), since proposals can continue to change before landing in browsers.
If you get a `SyntaxError: Unexpected token ...` error when using the [object-rest-spread](https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-object-rest-spread) transform then make sure the plugin has been updated to, at least, `v6.19.0`.
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