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Use for..of Object.keys instead of for..in (#9518)

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In https://github.com/babel/babel/issues/9511 (and #9495 is another symptom), @PavelKastornyy reported a node crash becaue the JavaScript heap run out of memory. The problem was that their code was adding enumerable properties to `Object.prototype`: it is something that shouldn't be done, but Babel shouldn't make node crash if someone adds them.
I reduced down the problem to `for...in` loops in `@babel/traverse` that grew the memory consumption exponentially because of that unexpected properties.
This commit is contained in:
Nicolò Ribaudo 2019-02-26 20:09:02 +01:00 committed by GitHub
parent f1ab6120d2
commit 0345c1bc1d
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
24 changed files with 60 additions and 55 deletions
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3
.eslintrc.json
View File

@ -14,7 +14,8 @@
"rules": {
"@babel/development/no-undefined-identifier": "error",
"@babel/development/no-deprecated-clone": "error",
"import/no-extraneous-dependencies": "error"
"import/no-extraneous-dependencies": "error",
"guard-for-in": "error"
}
},
{

2
packages/babel-helper-define-map/src/index.js
View File

@ -98,7 +98,7 @@ export function push(
}
export function hasComputed(mutatorMap: Object): boolean {
for (const key in mutatorMap) {
for (const key of Object.keys(mutatorMap)) {
if (mutatorMap[key]._computed) {
return true;
}

2
packages/babel-helper-hoist-variables/src/index.js
View File

@ -28,7 +28,7 @@ const visitor = {
);
}
for (const name in declar.getBindingIdentifiers()) {
for (const name of Object.keys(declar.getBindingIdentifiers())) {
state.emit(t.identifier(name), name, declar.node.init !== null);
}
}

2
packages/babel-parser/src/options.js
View File

@ -61,7 +61,7 @@ export const defaultOptions: Options = {
export function getOptions(opts: ?Options): Options {
const options: any = {};
for (const key in defaultOptions) {
for (const key of Object.keys(defaultOptions)) {
options[key] = opts && opts[key] != null ? opts[key] : defaultOptions[key];
}
return options;

4
packages/babel-parser/test/helpers/runFixtureTests.js
View File

@ -195,12 +195,12 @@ function misMatch(exp, act) {
return ppJSON(exp) + " !== " + ppJSON(act);
}
} else {
for (const prop in exp) {
for (const prop of Object.keys(exp)) {
const mis = misMatch(exp[prop], act[prop]);
if (mis) return addPath(mis, prop);
}
for (const prop in act) {
for (const prop of Object.keys(act)) {
if (typeof act[prop] === "function") {
continue;
}

2
packages/babel-plugin-proposal-object-rest-spread/src/index.js
View File

@ -302,7 +302,7 @@ export default declare((api, opts) => {
const specifiers = [];
for (const name in path.getOuterBindingIdentifiers(path)) {
for (const name of Object.keys(path.getOuterBindingIdentifiers(path))) {
specifiers.push(
t.exportSpecifier(t.identifier(name), t.identifier(name)),
);

20
packages/babel-plugin-transform-block-scoping/src/index.js
View File

@ -153,8 +153,7 @@ function convertBlockScopedToVar(
// Move bindings from current block scope to function scope.
if (moveBindingsToParent) {
const parentScope = scope.getFunctionParent() || scope.getProgramParent();
const ids = path.getBindingIdentifiers();
for (const name in ids) {
for (const name of Object.keys(path.getBindingIdentifiers())) {
const binding = scope.getOwnBinding(name);
if (binding) binding.kind = "var";
scope.moveBindingTo(name, parentScope);
@ -245,8 +244,7 @@ const loopLabelVisitor = {
const continuationVisitor = {
enter(path, state) {
if (path.isAssignmentExpression() || path.isUpdateExpression()) {
const bindings = path.getBindingIdentifiers();
for (const name in bindings) {
for (const name of Object.keys(path.getBindingIdentifiers())) {
if (
state.outsideReferences[name] !==
path.scope.getBindingIdentifier(name)
@ -410,7 +408,7 @@ class BlockScoping {
const scope = this.scope;
const state = this.state;
for (const name in scope.bindings) {
for (const name of Object.keys(scope.bindings)) {
const binding = scope.bindings[name];
if (binding.kind !== "const") continue;
@ -444,7 +442,7 @@ class BlockScoping {
const parentScope = scope.getFunctionParent() || scope.getProgramParent();
const letRefs = this.letReferences;
for (const key in letRefs) {
for (const key of Object.keys(letRefs)) {
const ref = letRefs[key];
const binding = scope.getBinding(ref.name);
if (!binding) continue;
@ -471,7 +469,7 @@ class BlockScoping {
// those in upper scopes and then if they do, generate a uid
// for them and replace all references with it
for (const key in letRefs) {
for (const key of Object.keys(letRefs)) {
// just an Identifier node we collected in `getLetReferences`
// this is the defining identifier of a declaration
const ref = letRefs[key];
@ -491,7 +489,7 @@ class BlockScoping {
}
}
for (const key in outsideLetRefs) {
for (const key of Object.keys(outsideLetRefs)) {
const ref = letRefs[key];
// check for collisions with a for loop's init variable and the enclosing scope's bindings
// https://github.com/babel/babel/issues/8498
@ -514,7 +512,7 @@ class BlockScoping {
// remap loop heads with colliding variables
if (this.loop) {
for (const name in outsideRefs) {
for (const name of Object.keys(outsideRefs)) {
const id = outsideRefs[name];
if (
@ -814,7 +812,7 @@ class BlockScoping {
pushDeclar(node: { type: "VariableDeclaration" }): Array<Object> {
const declars = [];
const names = t.getBindingIdentifiers(node);
for (const name in names) {
for (const name of Object.keys(names)) {
declars.push(t.variableDeclarator(names[name]));
}
@ -852,7 +850,7 @@ class BlockScoping {
}
if (has.hasBreakContinue) {
for (const key in has.map) {
for (const key of Object.keys(has.map)) {
cases.push(t.switchCase(t.stringLiteral(key), [has.map[key]]));
}

2
packages/babel-plugin-transform-block-scoping/src/tdz.js
View File

@ -83,7 +83,7 @@ export const visitor = {
const nodes = [];
const ids = path.getBindingIdentifiers();
for (const name in ids) {
for (const name of Object.keys(ids)) {
const id = ids[name];
if (isReference(id, path.scope, state)) {

2
packages/babel-plugin-transform-destructuring/src/index.js
View File

@ -421,7 +421,7 @@ export default declare((api, options) => {
const specifiers = [];
for (const name in path.getOuterBindingIdentifiers(path)) {
for (const name of Object.keys(path.getOuterBindingIdentifiers(path))) {
specifiers.push(
t.exportSpecifier(t.identifier(name), t.identifier(name)),
);

8
packages/babel-plugin-transform-modules-systemjs/src/index.js
View File

@ -113,7 +113,7 @@ export default declare((api, options) => {
if (arg.isObjectPattern() || arg.isArrayPattern()) {
const exprs = [path.node];
for (const name in arg.getBindingIdentifiers()) {
for (const name of Object.keys(arg.getBindingIdentifiers())) {
if (this.scope.getBinding(name) !== path.scope.getBinding(name)) {
return;
}
@ -266,7 +266,7 @@ export default declare((api, options) => {
} else if (path.isImportDeclaration()) {
const source = path.node.source.value;
pushModule(source, "imports", path.node.specifiers);
for (const name in path.getBindingIdentifiers()) {
for (const name of Object.keys(path.getBindingIdentifiers())) {
path.scope.removeBinding(name);
variableIds.push(t.identifier(name));
}
@ -320,7 +320,9 @@ export default declare((api, options) => {
addExportName(name, name);
path.insertAfter([buildExportCall(name, t.identifier(name))]);
} else {
for (const name in declar.getBindingIdentifiers()) {
for (const name of Object.keys(
declar.getBindingIdentifiers(),
)) {
addExportName(name, name);
}
}

2
packages/babel-traverse/src/path/context.js
View File

@ -169,7 +169,7 @@ export function _resyncKey() {
}
}
} else {
for (const key in this.container) {
for (const key of Object.keys(this.container)) {
if (this.container[key] === this.node) {
return this.setKey(key);
}

2
packages/babel-traverse/src/path/index.js
View File

@ -183,7 +183,7 @@ for (const type of (t.TYPES: Array<string>)) {
};
}
for (const type in virtualTypes) {
for (const type of Object.keys(virtualTypes)) {
if (type[0] === "_") continue;
if (t.TYPES.indexOf(type) < 0) t.TYPES.push(type);

6
packages/babel-traverse/src/path/lib/hoister.js
View File

@ -58,7 +58,7 @@ export default class PathHoister {
// A scope is compatible if all required bindings are reachable.
isCompatibleScope(scope) {
for (const key in this.bindings) {
for (const key of Object.keys(this.bindings)) {
const binding = this.bindings[key];
if (!scope.bindingIdentifierEquals(key, binding.identifier)) {
return false;
@ -98,7 +98,7 @@ export default class PathHoister {
// avoid hoisting to a scope that contains bindings that are executed after our attachment path
if (targetScope.path.isProgram() || targetScope.path.isFunction()) {
for (const name in this.bindings) {
for (const name of Object.keys(this.bindings)) {
// check binding is a direct child of this paths scope
if (!targetScope.hasOwnBinding(name)) continue;
@ -182,7 +182,7 @@ export default class PathHoister {
// Returns true if a scope has param bindings.
hasOwnParamBindings(scope) {
for (const name in this.bindings) {
for (const name of Object.keys(this.bindings)) {
if (!scope.hasOwnBinding(name)) continue;
const binding = this.bindings[name];

2
packages/babel-traverse/src/path/replacement.js
View File

@ -15,7 +15,7 @@ const hoistVariablesVisitor = {
if (path.node.kind !== "var") return;
const bindings = path.getBindingIdentifiers();
for (const key in bindings) {
for (const key of Object.keys(bindings)) {
path.scope.push({ id: bindings[key] });
}

13
packages/babel-traverse/src/scope/index.js
View File

@ -97,8 +97,7 @@ const collectorVisitor = {
if (binding) binding.reference(path);
} else if (t.isVariableDeclaration(declar)) {
for (const decl of (declar.declarations: Array<Object>)) {
const ids = t.getBindingIdentifiers(decl);
for (const name in ids) {
for (const name of Object.keys(t.getBindingIdentifiers(decl))) {
const binding = scope.getBinding(name);
if (binding) binding.reference(path);
}
@ -388,7 +387,7 @@ export default class Scope {
let scope = this;
do {
console.log("#", scope.block.type);
for (const name in scope.bindings) {
for (const name of Object.keys(scope.bindings)) {
const binding = scope.bindings[name];
console.log(" -", name, {
constant: binding.constant,
@ -501,7 +500,7 @@ export default class Scope {
registerConstantViolation(path: NodePath) {
const ids = path.getBindingIdentifiers();
for (const name in ids) {
for (const name of Object.keys(ids)) {
const binding = this.getBinding(name);
if (binding) binding.reassign(path);
}
@ -521,7 +520,7 @@ export default class Scope {
const parent = this.getProgramParent();
const ids = path.getBindingIdentifiers(true);
for (const name in ids) {
for (const name of Object.keys(ids)) {
for (const id of (ids[name]: Array<Object>)) {
const local = this.getOwnBinding(name);
@ -746,7 +745,7 @@ export default class Scope {
// register undeclared bindings as globals
const ids = path.getBindingIdentifiers();
let programParent;
for (const name in ids) {
for (const name of Object.keys(ids)) {
if (path.scope.getBinding(name)) continue;
programParent = programParent || path.scope.getProgramParent();
@ -886,7 +885,7 @@ export default class Scope {
for (const kind of (arguments: Array)) {
let scope = this;
do {
for (const name in scope.bindings) {
for (const name of Object.keys(scope.bindings)) {
const binding = scope.bindings[name];
if (binding.kind === kind) ids[name] = binding;
}

20
packages/babel-traverse/src/visitors.js
View File

@ -23,7 +23,7 @@ export function explode(visitor) {
visitor._exploded = true;
// normalise pipes
for (const nodeType in visitor) {
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
const parts: Array<string> = nodeType.split("|");
@ -59,7 +59,7 @@ export function explode(visitor) {
// wrap all the functions
const fns = visitor[nodeType];
for (const type in fns) {
for (const type of Object.keys(fns)) {
fns[type] = wrapCheck(wrapper, fns[type]);
}
@ -81,7 +81,7 @@ export function explode(visitor) {
}
// add aliases
for (const nodeType in visitor) {
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
const fns = visitor[nodeType];
@ -111,7 +111,7 @@ export function explode(visitor) {
}
}
for (const nodeType in visitor) {
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
ensureCallbackArrays(visitor[nodeType]);
@ -130,7 +130,7 @@ export function verify(visitor) {
);
}
for (const nodeType in visitor) {
for (const nodeType of Object.keys(visitor)) {
if (nodeType === "enter" || nodeType === "exit") {
validateVisitorMethods(nodeType, visitor[nodeType]);
}
@ -145,7 +145,7 @@ export function verify(visitor) {
const visitors = visitor[nodeType];
if (typeof visitors === "object") {
for (const visitorKey in visitors) {
for (const visitorKey of Object.keys(visitors)) {
if (visitorKey === "enter" || visitorKey === "exit") {
// verify that it just contains functions
validateVisitorMethods(
@ -189,7 +189,7 @@ export function merge(
explode(visitor);
for (const type in visitor) {
for (const type of Object.keys(visitor)) {
let visitorType = visitor[type];
// if we have state or wrapper then overload the callbacks to take it
@ -208,7 +208,7 @@ export function merge(
function wrapWithStateOrWrapper(oldVisitor, state, wrapper: ?Function) {
const newVisitor = {};
for (const key in oldVisitor) {
for (const key of Object.keys(oldVisitor)) {
let fns = oldVisitor[key];
// not an enter/exit array of callbacks
@ -237,7 +237,7 @@ function wrapWithStateOrWrapper(oldVisitor, state, wrapper: ?Function) {
}
function ensureEntranceObjects(obj) {
for (const key in obj) {
for (const key of Object.keys(obj)) {
if (shouldIgnoreKey(key)) continue;
const fns = obj[key];
@ -278,7 +278,7 @@ function shouldIgnoreKey(key) {
}
function mergePair(dest, src) {
for (const key in src) {
for (const key of Object.keys(src)) {
dest[key] = [].concat(dest[key] || [], src[key]);
}
}

2
packages/babel-types/src/builders/builder.js
View File

@ -28,7 +28,7 @@ export default function builder(type: string, ...args: Array<any>): Object {
i++;
});
for (const key in node) {
for (const key of Object.keys(node)) {
validate(node, key, node[key]);
}

2
packages/babel-types/src/converters/gatherSequenceExpressions.js
View File

@ -36,7 +36,7 @@ export default function gatherSequenceExpressions(
for (const declar of (node.declarations: Array<any>)) {
const bindings = getBindingIdentifiers(declar);
for (const key in bindings) {
for (const key of Object.keys(bindings)) {
declars.push({
kind: node.kind,
id: cloneNode(bindings[key]),

2
packages/babel-types/src/converters/valueToNode.js
View File

@ -77,7 +77,7 @@ export default function valueToNode(value: any): Object {
// object
if (isPlainObject(value)) {
const props = [];
for (const key in value) {
for (const key of Object.keys(value)) {
let nodeKey;
if (isValidIdentifier(key)) {
nodeKey = identifier(key);

2
packages/babel-types/src/definitions/utils.js
View File

@ -201,7 +201,7 @@ export default function defineType(
fields[key] = fields[key] || {};
}
for (const key in fields) {
for (const key of Object.keys(fields)) {
const field = fields[key];
if (builder.indexOf(key) === -1) {

4
packages/babel-types/src/modifications/flow/removeTypeDuplicates.js
View File

@ -73,12 +73,12 @@ export default function removeTypeDuplicates(
}
// add back in bases
for (const type in bases) {
for (const type of Object.keys(bases)) {
types.push(bases[type]);
}
// add back in generics
for (const name in generics) {
for (const name of Object.keys(generics)) {
types.push(generics[name]);
}

2
packages/babel-types/src/modifications/inherits.js
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@ -16,7 +16,7 @@ export default function inherits<T: Object>(child: T, parent: Object): T {
}
// force inherit "private" properties
for (const key in parent) {
for (const key of Object.keys(parent)) {
if (key[0] === "_" && key !== "__clone") child[key] = parent[key];
}

2
packages/babel-types/src/modifications/removeProperties.js
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@ -20,7 +20,7 @@ export default function removeProperties(
if (node[key] != null) node[key] = undefined;
}
for (const key in node) {
for (const key of Object.keys(node)) {
if (key[0] === "_" && node[key] != null) node[key] = undefined;
}

7
packages/babel-types/src/validators/isNodesEquivalent.js
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@ -25,6 +25,11 @@ export default function isNodesEquivalent(a: any, b: any): boolean {
if (typeof a[field] !== typeof b[field]) {
return false;
}
if (a[field] == null && b[field] == null) {
continue;
} else if (a[field] == null || b[field] == null) {
return false;
}
if (Array.isArray(a[field])) {
if (!Array.isArray(b[field])) {
@ -46,7 +51,7 @@ export default function isNodesEquivalent(a: any, b: any): boolean {
typeof a[field] === "object" &&
(!visitorKeys || !visitorKeys.includes(field))
) {
for (const key in a[field]) {
for (const key of Object.keys(a[field])) {
if (a[field][key] !== b[field][key]) {
return false;
}