fcdfc61bdb
* 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 !
babel-plugin-transform-optional-chaining
The Optional Chaining Operator allows you to handle properties of deeply nested objects without worrying about undefined intermediate objects.
Example
Accessing deeply nested properties
const obj = {
foo: {
bar: {
baz: 42,
},
},
};
const baz = obj?.foo?.bar?.baz; // 42
const safe = obj?.qux?.baz; // undefined
// Optional chaining and normal chaining can be intermixed
obj?.foo.bar?.baz; // Only access `foo` if `obj` exists, and `baz` if
// `bar` exists
Calling deeply nested functions
const obj = {
foo: {
bar: {
baz() {
return 42;
},
},
},
};
const baz = obj?.foo?.bar?.baz(); // 42
const safe = obj?.qux?.baz(); // undefined
const safe2 = obj?.foo.bar.qux?.(); // undefined
const willThrow = obj?.foo.bar.qux(); // Error: not a function
// Top function can be called directly, too.
function test() {
return 42;
}
test?.(); // 42
exists?.(); // undefined
Constructing deeply nested classes
const obj = {
foo: {
bar: {
baz: class {
},
},
},
};
const baz = new obj?.foo?.bar?.baz(); // baz instance
const safe = new obj?.qux?.baz(); // undefined
const safe2 = new obj?.foo.bar.qux?.(); // undefined
const willThrow = new obj?.foo.bar.qux(); // Error: not a constructor
// Top classes can be called directly, too.
class Test {
}
new Test?.(); // test instance
new exists?.(); // undefined
Installation
npm install --save-dev babel-plugin-transform-optional-chaining
Usage
Via .babelrc (Recommended)
.babelrc
{
"plugins": ["transform-optional-chaining"]
}
Via CLI
babel --plugins transform-optional-chaining script.js
Via Node API
require("babel-core").transform("code", {
plugins: ["transform-optional-chaining"]
});