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Convert proposal-object-rest-spread to TS (#13948)
* chore: add typings to object-rest-spread * chore: bundle object-rest-spread package * improve type inference * address review comments
1 parent ad1798e commit 55f020e

6 files changed

Lines changed: 105 additions & 56 deletions

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‎Gulpfile.mjs‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -461,6 +461,7 @@ function copyDts(packages) {
461461

462462
const libBundles = [
463463
"packages/babel-parser",
464+
"packages/babel-plugin-proposal-object-rest-spread",
464465
"packages/babel-plugin-proposal-optional-chaining",
465466
"packages/babel-preset-react",
466467
"packages/babel-preset-typescript",

packages/babel-plugin-proposal-object-rest-spread/src/index.js renamed to packages/babel-plugin-proposal-object-rest-spread/src/index.ts

Lines changed: 84 additions & 49 deletions
Original file line numberDiff line numberDiff line change
@@ -1,21 +1,24 @@
11
import { declare } from "@babel/helper-plugin-utils";
22
import syntaxObjectRestSpread from "@babel/plugin-syntax-object-rest-spread";
33
import { types as t } from "@babel/core";
4+
import type { PluginPass } from "@babel/core";
5+
import type { NodePath, Visitor, Scope } from "@babel/traverse";
46
import { convertFunctionParams } from "@babel/plugin-transform-parameters";
57
import { isRequired } from "@babel/helper-compilation-targets";
68
import compatData from "@babel/compat-data/corejs2-built-ins";
79
import shouldStoreRHSInTemporaryVariable from "./shouldStoreRHSInTemporaryVariable";
810

9-
// TODO: Remove in Babel 8
11+
const { isAssignmentPattern, isObjectProperty } = t;
1012
// @babel/types <=7.3.3 counts FOO as referenced in var { x: FOO }.
1113
// We need to detect this bug to know if "unused" means 0 or 1 references.
12-
const ZERO_REFS = (() => {
14+
if (!process.env.BABEL_8_BREAKING) {
1315
const node = t.identifier("a");
1416
const property = t.objectProperty(t.identifier("key"), node);
1517
const pattern = t.objectPattern([property]);
1618

17-
return t.isReferenced(node, property, pattern) ? 1 : 0;
18-
})();
19+
// eslint-disable-next-line no-var
20+
var ZERO_REFS = t.isReferenced(node, property, pattern) ? 1 : 0;
21+
}
1922

2023
export default declare((api, opts) => {
2124
api.assertVersion(7);
@@ -36,7 +39,9 @@ export default declare((api, opts) => {
3639
const pureGetters = api.assumption("pureGetters") ?? loose;
3740
const setSpreadProperties = api.assumption("setSpreadProperties") ?? loose;
3841

39-
function getExtendsHelper(file) {
42+
function getExtendsHelper(
43+
file: PluginPass,
44+
): t.MemberExpression | t.Identifier {
4045
return useBuiltIns
4146
? t.memberExpression(t.identifier("Object"), t.identifier("assign"))
4247
: file.addHelper("extends");
@@ -51,7 +56,7 @@ export default declare((api, opts) => {
5156
return foundRestElement;
5257
}
5358

54-
function hasObjectPatternRestElement(path) {
59+
function hasObjectPatternRestElement(path: NodePath): boolean {
5560
let foundRestElement = false;
5661
visitRestElements(path, restElement => {
5762
if (restElement.parentPath.isObjectPattern()) {
@@ -62,15 +67,16 @@ export default declare((api, opts) => {
6267
return foundRestElement;
6368
}
6469

65-
function visitRestElements(path, visitor) {
70+
function visitRestElements(
71+
path: NodePath,
72+
visitor: (path: NodePath<t.RestElement>) => any,
73+
) {
6674
path.traverse({
6775
Expression(path) {
68-
const parentType = path.parent.type;
76+
const { parent, key } = path;
6977
if (
70-
(parentType === "AssignmentPattern" && path.key === "right") ||
71-
(parentType === "ObjectProperty" &&
72-
path.parent.computed &&
73-
path.key === "key")
78+
(isAssignmentPattern(parent) && key === "right") ||
79+
(isObjectProperty(parent) && parent.computed && key === "key")
7480
) {
7581
path.skip();
7682
}
@@ -79,7 +85,7 @@ export default declare((api, opts) => {
7985
});
8086
}
8187

82-
function hasSpread(node) {
88+
function hasSpread(node: t.ObjectExpression): boolean {
8389
for (const prop of node.properties) {
8490
if (t.isSpreadElement(prop)) {
8591
return true;
@@ -92,9 +98,10 @@ export default declare((api, opts) => {
9298
// were converted to stringLiterals or not
9399
// e.g. extracts {keys: ["a", "b", "3", ++x], allLiteral: false }
94100
// from ast of {a: "foo", b, 3: "bar", [++x]: "baz"}
95-
function extractNormalizedKeys(path) {
96-
const props = path.node.properties;
97-
const keys = [];
101+
function extractNormalizedKeys(node: t.ObjectPattern) {
102+
// RestElement has been removed in createObjectRest
103+
const props = node.properties as t.ObjectProperty[];
104+
const keys: t.Expression[] = [];
98105
let allLiteral = true;
99106
let hasTemplateLiteral = false;
100107

@@ -106,7 +113,14 @@ export default declare((api, opts) => {
106113
keys.push(t.cloneNode(prop.key));
107114
hasTemplateLiteral = true;
108115
} else if (t.isLiteral(prop.key)) {
109-
keys.push(t.stringLiteral(String(prop.key.value)));
116+
keys.push(
117+
t.stringLiteral(
118+
String(
119+
//@ts-ignore prop.key can not be a NullLiteral
120+
prop.key.value,
121+
),
122+
),
123+
);
110124
} else {
111125
keys.push(t.cloneNode(prop.key));
112126
allLiteral = false;
@@ -118,8 +132,11 @@ export default declare((api, opts) => {
118132

119133
// replaces impure computed keys with new identifiers
120134
// and returns variable declarators of these new identifiers
121-
function replaceImpureComputedKeys(properties, scope) {
122-
const impureComputedPropertyDeclarators = [];
135+
function replaceImpureComputedKeys(
136+
properties: NodePath<t.ObjectProperty>[],
137+
scope: Scope,
138+
) {
139+
const impureComputedPropertyDeclarators: t.VariableDeclarator[] = [];
123140
for (const propPath of properties) {
124141
const key = propPath.get("key");
125142
if (propPath.node.computed && !key.isPure()) {
@@ -132,13 +149,14 @@ export default declare((api, opts) => {
132149
return impureComputedPropertyDeclarators;
133150
}
134151

135-
function removeUnusedExcludedKeys(path) {
152+
function removeUnusedExcludedKeys(path: NodePath<t.ObjectPattern>): void {
136153
const bindings = path.getOuterBindingIdentifierPaths();
137154

138155
Object.keys(bindings).forEach(bindingName => {
139156
const bindingParentPath = bindings[bindingName].parentPath;
140157
if (
141-
path.scope.getBinding(bindingName).references > ZERO_REFS ||
158+
path.scope.getBinding(bindingName).references >
159+
(process.env.BABEL_8_BREAKING ? 0 : ZERO_REFS) ||
142160
!bindingParentPath.isObjectProperty()
143161
) {
144162
return;
@@ -148,19 +166,24 @@ export default declare((api, opts) => {
148166
}
149167

150168
//expects path to an object pattern
151-
function createObjectRest(path, file, objRef) {
169+
function createObjectRest(
170+
path: NodePath<t.ObjectPattern>,
171+
file: PluginPass,
172+
objRef: t.Identifier | t.MemberExpression,
173+
): [t.VariableDeclarator[], t.LVal, t.CallExpression] {
152174
const props = path.get("properties");
153175
const last = props[props.length - 1];
154176
t.assertRestElement(last.node);
155177
const restElement = t.cloneNode(last.node);
156178
last.remove();
157179

158180
const impureComputedPropertyDeclarators = replaceImpureComputedKeys(
159-
path.get("properties"),
181+
path.get("properties") as NodePath<t.ObjectProperty>[],
160182
path.scope,
161183
);
162-
const { keys, allLiteral, hasTemplateLiteral } =
163-
extractNormalizedKeys(path);
184+
const { keys, allLiteral, hasTemplateLiteral } = extractNormalizedKeys(
185+
path.node,
186+
);
164187

165188
if (keys.length === 0) {
166189
return [
@@ -210,7 +233,11 @@ export default declare((api, opts) => {
210233
];
211234
}
212235

213-
function replaceRestElement(parentPath, paramPath, container) {
236+
function replaceRestElement(
237+
parentPath: NodePath<t.Function | t.CatchClause>,
238+
paramPath: NodePath,
239+
container?: t.VariableDeclaration[],
240+
): void {
214241
if (paramPath.isAssignmentPattern()) {
215242
replaceRestElement(parentPath, paramPath.get("left"), container);
216243
return;
@@ -299,7 +326,7 @@ export default declare((api, opts) => {
299326
for (let i = 0; i < params.length; ++i) {
300327
const param = params[i];
301328
if (paramsWithRestElement.has(i)) {
302-
replaceRestElement(param.parentPath, param);
329+
replaceRestElement(path, param);
303330
}
304331
}
305332
} else {
@@ -360,14 +387,15 @@ export default declare((api, opts) => {
360387
}
361388

362389
let ref = originalPath.node.init;
363-
const refPropertyPath = [];
390+
const refPropertyPath: NodePath<t.ObjectProperty>[] = [];
364391
let kind;
365392

366-
path.findParent(path => {
393+
path.findParent((path: NodePath): boolean => {
367394
if (path.isObjectProperty()) {
368395
refPropertyPath.unshift(path);
369396
} else if (path.isVariableDeclarator()) {
370-
kind = path.parentPath.node.kind;
397+
kind = (path.parentPath as NodePath<t.VariableDeclaration>).node
398+
.kind;
371399
return true;
372400
}
373401
});
@@ -385,12 +413,17 @@ export default declare((api, opts) => {
385413
);
386414
});
387415

388-
const objectPatternPath = path.findParent(path =>
389-
path.isObjectPattern(),
416+
//@ts-expect-error: findParent can not apply assertions on result shape
417+
const objectPatternPath: NodePath<t.ObjectPattern> = path.findParent(
418+
path => path.isObjectPattern(),
390419
);
391420

392421
const [impureComputedPropertyDeclarators, argument, callExpression] =
393-
createObjectRest(objectPatternPath, file, ref);
422+
createObjectRest(
423+
objectPatternPath,
424+
file,
425+
ref as t.MemberExpression,
426+
);
394427

395428
if (pureGetters) {
396429
removeUnusedExcludedKeys(objectPatternPath);
@@ -402,11 +435,9 @@ export default declare((api, opts) => {
402435

403436
insertionPath.insertBefore(impureObjRefComputedDeclarators);
404437

405-
insertionPath.insertAfter(
438+
insertionPath = insertionPath.insertAfter(
406439
t.variableDeclarator(argument, callExpression),
407-
);
408-
409-
insertionPath = insertionPath.getSibling(insertionPath.key + 1);
440+
)[0] as NodePath<t.VariableDeclarator>;
410441

411442
path.scope.registerBinding(kind, insertionPath);
412443

@@ -433,7 +464,7 @@ export default declare((api, opts) => {
433464

434465
const specifiers = [];
435466

436-
for (const name of Object.keys(path.getOuterBindingIdentifiers(path))) {
467+
for (const name of Object.keys(path.getOuterBindingIdentifiers(true))) {
437468
specifiers.push(
438469
t.exportSpecifier(t.identifier(name), t.identifier(name)),
439470
);
@@ -449,7 +480,7 @@ export default declare((api, opts) => {
449480
// try {} catch ({a, ...b}) {}
450481
CatchClause(path) {
451482
const paramPath = path.get("param");
452-
replaceRestElement(paramPath.parentPath, paramPath);
483+
replaceRestElement(path, paramPath);
453484
},
454485

455486
// ({a, ...b} = c);
@@ -511,14 +542,15 @@ export default declare((api, opts) => {
511542
]);
512543

513544
path.ensureBlock();
545+
const body = node.body as t.BlockStatement;
514546

515-
if (node.body.body.length === 0 && path.isCompletionRecord()) {
516-
node.body.body.unshift(
547+
if (body.body.length === 0 && path.isCompletionRecord()) {
548+
body.body.unshift(
517549
t.expressionStatement(scope.buildUndefinedNode()),
518550
);
519551
}
520552

521-
node.body.body.unshift(
553+
body.body.unshift(
522554
t.expressionStatement(
523555
t.assignmentExpression("=", left, t.cloneNode(temp)),
524556
),
@@ -533,8 +565,9 @@ export default declare((api, opts) => {
533565
]);
534566

535567
path.ensureBlock();
568+
const body = node.body as t.BlockStatement;
536569

537-
node.body.body.unshift(
570+
body.body.unshift(
538571
t.variableDeclaration(node.left.kind, [
539572
t.variableDeclarator(pattern, t.cloneNode(key)),
540573
]),
@@ -565,11 +598,13 @@ export default declare((api, opts) => {
565598

566599
if (objectPatterns.length > 0) {
567600
const statementPath = path.getStatementParent();
601+
const statementNode = statementPath.node;
602+
const kind =
603+
statementNode.type === "VariableDeclaration"
604+
? statementNode.kind
605+
: "var";
568606
statementPath.insertAfter(
569-
t.variableDeclaration(
570-
statementPath.node.kind || "var",
571-
objectPatterns,
572-
),
607+
t.variableDeclaration(kind, objectPatterns),
573608
);
574609
}
575610
},
@@ -627,7 +662,7 @@ export default declare((api, opts) => {
627662
]);
628663
}
629664

630-
for (const prop of (path.node.properties: Array)) {
665+
for (const prop of path.node.properties) {
631666
if (t.isSpreadElement(prop)) {
632667
make();
633668
exp.arguments.push(prop.argument);
@@ -640,6 +675,6 @@ export default declare((api, opts) => {
640675

641676
path.replaceWith(exp);
642677
},
643-
},
678+
} as Visitor<PluginPass>,
644679
};
645680
});

packages/babel-plugin-proposal-object-rest-spread/src/shouldStoreRHSInTemporaryVariable.js renamed to packages/babel-plugin-proposal-object-rest-spread/src/shouldStoreRHSInTemporaryVariable.ts

Lines changed: 14 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -1,23 +1,31 @@
11
import { types as t } from "@babel/core";
22

3+
const { isObjectProperty } = t;
34
/**
45
* This is a helper function to determine if we should create an intermediate variable
56
* such that the RHS of an assignment is not duplicated.
67
*
78
* See https://github.com/babel/babel/pull/13711#issuecomment-914388382 for discussion
89
* on further optimizations.
910
*/
10-
export default function shouldStoreRHSInTemporaryVariable(node) {
11+
export default function shouldStoreRHSInTemporaryVariable(node: t.LVal) {
1112
if (t.isArrayPattern(node)) {
1213
const nonNullElements = node.elements.filter(element => element !== null);
1314
if (nonNullElements.length > 1) return true;
1415
else return shouldStoreRHSInTemporaryVariable(nonNullElements[0]);
1516
} else if (t.isObjectPattern(node)) {
16-
if (node.properties.length > 1) return true;
17-
else if (node.properties.length === 0) return false;
18-
else return shouldStoreRHSInTemporaryVariable(node.properties[0]);
19-
} else if (t.isObjectProperty(node)) {
20-
return shouldStoreRHSInTemporaryVariable(node.value);
17+
const { properties } = node;
18+
if (properties.length > 1) return true;
19+
else if (properties.length === 0) return false;
20+
else {
21+
const firstProperty = properties[0];
22+
if (isObjectProperty(firstProperty)) {
23+
// the value of the property must be an LVal
24+
return shouldStoreRHSInTemporaryVariable(firstProperty.value as t.LVal);
25+
} else {
26+
return shouldStoreRHSInTemporaryVariable(firstProperty);
27+
}
28+
}
2129
} else if (t.isAssignmentPattern(node)) {
2230
return shouldStoreRHSInTemporaryVariable(node.left);
2331
} else if (t.isRestElement(node)) {

‎packages/babel-traverse/src/path/ancestry.ts‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -12,6 +12,7 @@ import NodePath from "./index";
1212
*/
1313

1414
export function findParent(
15+
this: NodePath,
1516
callback: (path: NodePath) => boolean,
1617
): NodePath | null {
1718
let path = this;

‎packages/babel-traverse/src/scope/index.ts‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -983,7 +983,7 @@ export default class Scope {
983983
init?: t.Expression;
984984
unique?: boolean;
985985
_blockHoist?: number | undefined;
986-
kind?: "var" | "let";
986+
kind?: "var" | "let" | "const";
987987
}) {
988988
let path = this.path;
989989

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