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Reland "Fix: check if param is assignable when parsing arrow return type annotation" (#12183)

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* Reland "Fix: check if param is assignable when parsing arrow return type annotation"

This reverts commit 91a7a64b4b0c30ab1fdfbb12f77522afa2285ec4.

* Mark `RestElement` as assignable
This commit is contained in:
Nicolò Ribaudo 2020-10-15 17:32:37 +02:00 committed by GitHub
parent 6cb0056519
commit 84987a00e6
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
11 changed files with 474 additions and 47 deletions
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7
packages/babel-parser/src/parser/expression.js
View File

@ -1453,7 +1453,7 @@ export default class ExpressionParser extends LValParser {
if (
canBeArrow &&
this.shouldParseArrow() &&
(arrowNode = this.parseArrow(arrowNode))
(arrowNode = this.parseArrow(arrowNode, exprList))
) {
if (!this.isAwaitAllowed() && !this.state.maybeInAsyncArrowHead) {
this.state.awaitPos = oldAwaitPos;
@ -1509,7 +1509,10 @@ export default class ExpressionParser extends LValParser {
return !this.canInsertSemicolon();
}
parseArrow(node: N.ArrowFunctionExpression): ?N.ArrowFunctionExpression {
parseArrow(
node: N.ArrowFunctionExpression,
exprList: N.Node[], // eslint-disable-line no-unused-vars
): ?N.ArrowFunctionExpression {
if (this.eat(tt.arrow)) {
return node;
}

54
packages/babel-parser/src/parser/lval.js
View File

@ -51,10 +51,60 @@ export default class LValParser extends NodeUtils {
+parseDecorator: () => Decorator;
*/
/**
* Check if a node can be converted to a binding identifier or binding pattern.
* https://tc39.es/ecma262/#prod-BindingIdentifier
* https://tc39.es/ecma262/#prod-BindingPattern
* Note that although a mebmer expression can serve as a LHS in the init of for loop,
* i.e. `for (a.b of []);`, it is not a binding pattern
*
* @param {Node} node
* @returns {boolean}
* @memberof LValParser
*/
isAssignable(node: Node): boolean {
switch (node.type) {
case "Identifier":
case "ObjectPattern":
case "ArrayPattern":
case "AssignmentPattern":
case "RestElement":
return true;
case "ObjectExpression": {
const last = node.properties.length - 1;
return node.properties.every((prop, i) => {
return (
prop.type !== "ObjectMethod" &&
(i === last || prop.type === "SpreadElement") &&
this.isAssignable(prop)
);
});
}
case "ObjectProperty":
return this.isAssignable(node.value);
case "SpreadElement":
return this.isAssignable(node.argument);
case "ArrayExpression":
return node.elements.every(element => this.isAssignable(element));
case "AssignmentExpression":
return node.operator === "=";
case "ParenthesizedExpression":
return this.isAssignable(node.expression);
default:
return false;
}
}
// Convert existing expression atom to assignable pattern
// if possible.
// NOTE: There is a corresponding "isAssignable" method in flow.js.
// When this one is updated, please check if also that one needs to be updated.
// When this one is updated, please check if `isAssignable` also needs to be updated.
toAssignable(node: Node): Node {
let parenthesized = undefined;

51
packages/babel-parser/src/plugins/flow.js
View File

@ -1943,7 +1943,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
}
return partition(arrows, node =>
node.params.every(param => this.isAssignable(param, true)),
node.params.every(param => this.isAssignable(param)),
);
}
@ -2146,47 +2146,12 @@ export default (superClass: Class<Parser>): Class<Parser> =>
}
}
isAssignable(node: N.Node, isBinding?: boolean): boolean {
isAssignable(node: N.Node): boolean {
switch (node.type) {
case "Identifier":
case "ObjectPattern":
case "ArrayPattern":
case "AssignmentPattern":
return true;
case "ObjectExpression": {
const last = node.properties.length - 1;
return node.properties.every((prop, i) => {
return (
prop.type !== "ObjectMethod" &&
(i === last || prop.type === "SpreadElement") &&
this.isAssignable(prop)
);
});
}
case "ObjectProperty":
return this.isAssignable(node.value);
case "SpreadElement":
return this.isAssignable(node.argument);
case "ArrayExpression":
return node.elements.every(element => this.isAssignable(element));
case "AssignmentExpression":
return node.operator === "=";
case "ParenthesizedExpression":
case "TypeCastExpression":
return this.isAssignable(node.expression);
case "MemberExpression":
case "OptionalMemberExpression":
return !isBinding;
default:
return false;
return super.isAssignable(node);
}
}
@ -2772,7 +2737,10 @@ export default (superClass: Class<Parser>): Class<Parser> =>
}
// handle return types for arrow functions
parseArrow(node: N.ArrowFunctionExpression): ?N.ArrowFunctionExpression {
parseArrow(
node: N.ArrowFunctionExpression,
exprList: N.Node[],
): ?N.ArrowFunctionExpression {
if (this.match(tt.colon)) {
const result = this.tryParse(() => {
const oldNoAnonFunctionType = this.state.noAnonFunctionType;
@ -2806,7 +2774,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
: null;
}
return super.parseArrow(node);
return super.parseArrow(node, exprList);
}
shouldParseArrow(): boolean {
@ -2977,7 +2945,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
): ?N.ArrowFunctionExpression {
const node = this.startNodeAt(startPos, startLoc);
this.parseFunctionParams(node);
if (!this.parseArrow(node)) return;
// set exprList to `[]` as the parameters has been validated in `parseFunctionParams`
if (!this.parseArrow(node, [])) return;
return this.parseArrowExpression(
node,
/* params */ undefined,

23
packages/babel-parser/src/plugins/typescript/index.js
View File

@ -2540,7 +2540,10 @@ export default (superClass: Class<Parser>): Class<Parser> =>
}
}
parseArrow(node: N.ArrowFunctionExpression): ?N.ArrowFunctionExpression {
parseArrow(
node: N.ArrowFunctionExpression,
exprList,
): ?N.ArrowFunctionExpression {
if (this.match(tt.colon)) {
// This is different from how the TS parser does it.
// TS uses lookahead. The Babel Parser parses it as a parenthesized expression and converts.
@ -2550,6 +2553,10 @@ export default (superClass: Class<Parser>): Class<Parser> =>
tt.colon,
);
if (this.canInsertSemicolon() || !this.match(tt.arrow)) abort();
// check if the exprList is assignable because `: TSType` can be part of conditional expression
// i.e. we can only know `: v` is not a return type by checking that `sum(v)` can not be a pattern.
// 0 ? v => (sum(v)) : v => 0
if (exprList.some(param => !this.isAssignable(param))) abort();
return returnType;
});
@ -2561,7 +2568,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
}
}
return super.parseArrow(node);
return super.parseArrow(node, exprList);
}
// Allow type annotations inside of a parameter list.
@ -2580,6 +2587,18 @@ export default (superClass: Class<Parser>): Class<Parser> =>
return param;
}
isAssignable(node: N.Node): boolean {
switch (node.type) {
case "TSAsExpression":
case "TSNonNullExpression":
case "TSTypeAssertion":
case "TSTypeCastExpression":
return this.isAssignable(node.expression);
default:
return super.isAssignable(node);
}
}
toAssignable(node: N.Node): N.Node {
switch (node.type) {
case "TSTypeCastExpression":

1
packages/babel-parser/test/fixtures/typescript/arrow-function/ambiguous-ternary-arrow-return-type-typescript-issue-16241/input.ts vendored Normal file
View File

@ -0,0 +1 @@
0 ? v => (v) : v => 0;

7
packages/babel-parser/test/fixtures/typescript/arrow-function/ambiguous-ternary-arrow-return-type-typescript-issue-16241/options.json vendored Normal file
View File

@ -0,0 +1,7 @@
{
"sourceType": "module",
"plugins": [
"typescript"
],
"throws": "Unexpected token, expected \":\" (1:21)"
}

4
packages/babel-parser/test/fixtures/typescript/arrow-function/return-type-like-conditional/input.ts vendored Normal file
View File

@ -0,0 +1,4 @@
0 ? v => (sum += v) : v => 0;
0 ? v => (sum(v)) : v => 0;
0 ? v => (v.w) : v => 0;
0 ? v => ([ v.w ]) : v => {};

3
packages/babel-parser/test/fixtures/typescript/arrow-function/return-type-like-conditional/options.json vendored Normal file
View File

@ -0,0 +1,3 @@
{
"plugins": ["typescript"]
}

309
packages/babel-parser/test/fixtures/typescript/arrow-function/return-type-like-conditional/output.json vendored Normal file
View File

@ -0,0 +1,309 @@
{
"type": "File",
"start":0,"end":112,"loc":{"start":{"line":1,"column":0},"end":{"line":4,"column":29}},
"program": {
"type": "Program",
"start":0,"end":112,"loc":{"start":{"line":1,"column":0},"end":{"line":4,"column":29}},
"sourceType": "module",
"interpreter": null,
"body": [
{
"type": "ExpressionStatement",
"start":0,"end":29,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":29}},
"expression": {
"type": "ConditionalExpression",
"start":0,"end":28,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":28}},
"test": {
"type": "NumericLiteral",
"start":0,"end":1,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":1}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
},
"consequent": {
"type": "ArrowFunctionExpression",
"start":4,"end":19,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":19}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":4,"end":5,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":5},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "AssignmentExpression",
"start":10,"end":18,"loc":{"start":{"line":1,"column":10},"end":{"line":1,"column":18}},
"operator": "+=",
"left": {
"type": "Identifier",
"start":10,"end":13,"loc":{"start":{"line":1,"column":10},"end":{"line":1,"column":13},"identifierName":"sum"},
"name": "sum"
},
"right": {
"type": "Identifier",
"start":17,"end":18,"loc":{"start":{"line":1,"column":17},"end":{"line":1,"column":18},"identifierName":"v"},
"name": "v"
},
"extra": {
"parenthesized": true,
"parenStart": 9
}
}
},
"alternate": {
"type": "ArrowFunctionExpression",
"start":22,"end":28,"loc":{"start":{"line":1,"column":22},"end":{"line":1,"column":28}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":22,"end":23,"loc":{"start":{"line":1,"column":22},"end":{"line":1,"column":23},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "NumericLiteral",
"start":27,"end":28,"loc":{"start":{"line":1,"column":27},"end":{"line":1,"column":28}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
}
}
}
},
{
"type": "ExpressionStatement",
"start":30,"end":57,"loc":{"start":{"line":2,"column":0},"end":{"line":2,"column":27}},
"expression": {
"type": "ConditionalExpression",
"start":30,"end":56,"loc":{"start":{"line":2,"column":0},"end":{"line":2,"column":26}},
"test": {
"type": "NumericLiteral",
"start":30,"end":31,"loc":{"start":{"line":2,"column":0},"end":{"line":2,"column":1}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
},
"consequent": {
"type": "ArrowFunctionExpression",
"start":34,"end":47,"loc":{"start":{"line":2,"column":4},"end":{"line":2,"column":17}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":34,"end":35,"loc":{"start":{"line":2,"column":4},"end":{"line":2,"column":5},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "CallExpression",
"start":40,"end":46,"loc":{"start":{"line":2,"column":10},"end":{"line":2,"column":16}},
"callee": {
"type": "Identifier",
"start":40,"end":43,"loc":{"start":{"line":2,"column":10},"end":{"line":2,"column":13},"identifierName":"sum"},
"name": "sum"
},
"arguments": [
{
"type": "Identifier",
"start":44,"end":45,"loc":{"start":{"line":2,"column":14},"end":{"line":2,"column":15},"identifierName":"v"},
"name": "v"
}
],
"extra": {
"parenthesized": true,
"parenStart": 39
}
}
},
"alternate": {
"type": "ArrowFunctionExpression",
"start":50,"end":56,"loc":{"start":{"line":2,"column":20},"end":{"line":2,"column":26}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":50,"end":51,"loc":{"start":{"line":2,"column":20},"end":{"line":2,"column":21},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "NumericLiteral",
"start":55,"end":56,"loc":{"start":{"line":2,"column":25},"end":{"line":2,"column":26}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
}
}
}
},
{
"type": "ExpressionStatement",
"start":58,"end":82,"loc":{"start":{"line":3,"column":0},"end":{"line":3,"column":24}},
"expression": {
"type": "ConditionalExpression",
"start":58,"end":81,"loc":{"start":{"line":3,"column":0},"end":{"line":3,"column":23}},
"test": {
"type": "NumericLiteral",
"start":58,"end":59,"loc":{"start":{"line":3,"column":0},"end":{"line":3,"column":1}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
},
"consequent": {
"type": "ArrowFunctionExpression",
"start":62,"end":72,"loc":{"start":{"line":3,"column":4},"end":{"line":3,"column":14}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":62,"end":63,"loc":{"start":{"line":3,"column":4},"end":{"line":3,"column":5},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "MemberExpression",
"start":68,"end":71,"loc":{"start":{"line":3,"column":10},"end":{"line":3,"column":13}},
"object": {
"type": "Identifier",
"start":68,"end":69,"loc":{"start":{"line":3,"column":10},"end":{"line":3,"column":11},"identifierName":"v"},
"name": "v"
},
"computed": false,
"property": {
"type": "Identifier",
"start":70,"end":71,"loc":{"start":{"line":3,"column":12},"end":{"line":3,"column":13},"identifierName":"w"},
"name": "w"
},
"extra": {
"parenthesized": true,
"parenStart": 67
}
}
},
"alternate": {
"type": "ArrowFunctionExpression",
"start":75,"end":81,"loc":{"start":{"line":3,"column":17},"end":{"line":3,"column":23}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":75,"end":76,"loc":{"start":{"line":3,"column":17},"end":{"line":3,"column":18},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "NumericLiteral",
"start":80,"end":81,"loc":{"start":{"line":3,"column":22},"end":{"line":3,"column":23}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
}
}
}
},
{
"type": "ExpressionStatement",
"start":83,"end":112,"loc":{"start":{"line":4,"column":0},"end":{"line":4,"column":29}},
"expression": {
"type": "ConditionalExpression",
"start":83,"end":111,"loc":{"start":{"line":4,"column":0},"end":{"line":4,"column":28}},
"test": {
"type": "NumericLiteral",
"start":83,"end":84,"loc":{"start":{"line":4,"column":0},"end":{"line":4,"column":1}},
"extra": {
"rawValue": 0,
"raw": "0"
},
"value": 0
},
"consequent": {
"type": "ArrowFunctionExpression",
"start":87,"end":101,"loc":{"start":{"line":4,"column":4},"end":{"line":4,"column":18}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":87,"end":88,"loc":{"start":{"line":4,"column":4},"end":{"line":4,"column":5},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "ArrayExpression",
"start":93,"end":100,"loc":{"start":{"line":4,"column":10},"end":{"line":4,"column":17}},
"elements": [
{
"type": "MemberExpression",
"start":95,"end":98,"loc":{"start":{"line":4,"column":12},"end":{"line":4,"column":15}},
"object": {
"type": "Identifier",
"start":95,"end":96,"loc":{"start":{"line":4,"column":12},"end":{"line":4,"column":13},"identifierName":"v"},
"name": "v"
},
"computed": false,
"property": {
"type": "Identifier",
"start":97,"end":98,"loc":{"start":{"line":4,"column":14},"end":{"line":4,"column":15},"identifierName":"w"},
"name": "w"
}
}
],
"extra": {
"parenthesized": true,
"parenStart": 92
}
}
},
"alternate": {
"type": "ArrowFunctionExpression",
"start":104,"end":111,"loc":{"start":{"line":4,"column":21},"end":{"line":4,"column":28}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "Identifier",
"start":104,"end":105,"loc":{"start":{"line":4,"column":21},"end":{"line":4,"column":22},"identifierName":"v"},
"name": "v"
}
],
"body": {
"type": "BlockStatement",
"start":109,"end":111,"loc":{"start":{"line":4,"column":26},"end":{"line":4,"column":28}},
"body": [],
"directives": []
}
}
}
}
],
"directives": []
}
}

1
packages/babel-parser/test/fixtures/typescript/regression/rest-in-arrow/input.ts vendored Normal file
View File

@ -0,0 +1 @@
const f = (...args): void => {};

61
packages/babel-parser/test/fixtures/typescript/regression/rest-in-arrow/output.json vendored Normal file
View File

@ -0,0 +1,61 @@
{
"type": "File",
"start":0,"end":32,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":32}},
"program": {
"type": "Program",
"start":0,"end":32,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":32}},
"sourceType": "module",
"interpreter": null,
"body": [
{
"type": "VariableDeclaration",
"start":0,"end":32,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":32}},
"declarations": [
{
"type": "VariableDeclarator",
"start":6,"end":31,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":31}},
"id": {
"type": "Identifier",
"start":6,"end":7,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":7},"identifierName":"f"},
"name": "f"
},
"init": {
"type": "ArrowFunctionExpression",
"start":10,"end":31,"loc":{"start":{"line":1,"column":10},"end":{"line":1,"column":31}},
"returnType": {
"type": "TSTypeAnnotation",
"start":19,"end":25,"loc":{"start":{"line":1,"column":19},"end":{"line":1,"column":25}},
"typeAnnotation": {
"type": "TSVoidKeyword",
"start":21,"end":25,"loc":{"start":{"line":1,"column":21},"end":{"line":1,"column":25}}
}
},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "RestElement",
"start":11,"end":18,"loc":{"start":{"line":1,"column":11},"end":{"line":1,"column":18}},
"argument": {
"type": "Identifier",
"start":14,"end":18,"loc":{"start":{"line":1,"column":14},"end":{"line":1,"column":18},"identifierName":"args"},
"name": "args"
}
}
],
"body": {
"type": "BlockStatement",
"start":29,"end":31,"loc":{"start":{"line":1,"column":29},"end":{"line":1,"column":31}},
"body": [],
"directives": []
}
}
}
],
"kind": "const"
}
],
"directives": []
}
}