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fix: do not record errors on ancestry arrow head
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@JLHwung
JLHwung committed Nov 9, 2020
1 parent e9c2070 commit cc6569c
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Showing 5 changed files with 177 additions and 3 deletions.
22 changes: 19 additions & 3 deletions packages/babel-parser/src/util/expression-scope.js
View file
Expand Up @@ -140,15 +140,31 @@ export default class ExpressionScopeHandler {
* For example, in `([(a) = []] = []) => {}`, we think `(a) = []` is an LHS in `[(a) = []]`,
* an LHS within `[(a) = []] = []`. However the LHS chain is then transformed by toAssignable,
* and we should throw assignment `(a)`, which is only valid in LHS. Hence we record the
* location of parenthesized `(a)` to any ancestry MaybeArrowParameterDeclaration
* and MaybeAsyncArrowParameterDeclaration scope until an Expression scope is seen
* location of parenthesized `(a)` to current scope if it is one of MaybeArrowParameterDeclaration
* and MaybeAsyncArrowParameterDeclaration
*
* Unlike `recordParameterInitializerError`, we don't have to record on ancestry scope because we
* will validate arrow head parsing scope before exit. When it is validated, it is unambiguous and
* the LHS can no longer be transformed to pattern in upper arrow head scope.
* For example, in `( x = ( [(a) = []] = [] ) ) => {}`, we should not record `(a)` in `( x = ... ) =>`
* arrow scope because when we finish parsing `( [(a) = []] = [] )`, it is an umbiguous assignment
* expression and can not be cast to pattern
* @param {number} pos
* @param {string} message
* @returns {void}
* @memberof ExpressionScopeHandler
*/
recordParenthesizedIdentifierError(pos: number, message: string): void {
return this.recordParameterInitializerError(pos, message);
const { stack } = this;
const scope: ExpressionScope = stack[stack.length - 1];
if (scope.isCertainlyParameterDeclaration()) {
this.raise(pos, message);
} else if (scope.canBeArrowParameterDeclaration()) {
/*:: invariant(scope instanceof ArrowHeadParsingScope) */
scope.recordDeclarationError(pos, message);
} else {
return;
}
}

/**
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1 change: 1 addition & 0 deletions ...er/test/fixtures/es2015/arrow-functions/parenthesized-lhs-in-parethesis-in-param/input.js
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@@ -0,0 +1 @@
(x = ([(f) = []] = [])) => {};
79 changes: 79 additions & 0 deletions ...test/fixtures/es2015/arrow-functions/parenthesized-lhs-in-parethesis-in-param/output.json
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@@ -0,0 +1,79 @@
{
"type": "File",
"start":0,"end":30,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":30}},
"program": {
"type": "Program",
"start":0,"end":30,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":30}},
"sourceType": "script",
"interpreter": null,
"body": [
{
"type": "ExpressionStatement",
"start":0,"end":30,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":30}},
"expression": {
"type": "ArrowFunctionExpression",
"start":0,"end":29,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":29}},
"id": null,
"generator": false,
"async": false,
"params": [
{
"type": "AssignmentPattern",
"start":1,"end":22,"loc":{"start":{"line":1,"column":1},"end":{"line":1,"column":22}},
"left": {
"type": "Identifier",
"start":1,"end":2,"loc":{"start":{"line":1,"column":1},"end":{"line":1,"column":2},"identifierName":"x"},
"name": "x"
},
"right": {
"type": "AssignmentExpression",
"start":6,"end":21,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":21}},
"extra": {
"parenthesized": true,
"parenStart": 5
},
"operator": "=",
"left": {
"type": "ArrayPattern",
"start":6,"end":16,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":16}},
"elements": [
{
"type": "AssignmentPattern",
"start":7,"end":15,"loc":{"start":{"line":1,"column":7},"end":{"line":1,"column":15}},
"left": {
"type": "Identifier",
"start":8,"end":9,"loc":{"start":{"line":1,"column":8},"end":{"line":1,"column":9},"identifierName":"f"},
"extra": {
"parenthesized": true,
"parenStart": 7
},
"name": "f"
},
"right": {
"type": "ArrayExpression",
"start":13,"end":15,"loc":{"start":{"line":1,"column":13},"end":{"line":1,"column":15}},
"elements": []
}
}
]
},
"right": {
"type": "ArrayExpression",
"start":19,"end":21,"loc":{"start":{"line":1,"column":19},"end":{"line":1,"column":21}},
"elements": []
}
}
}
],
"body": {
"type": "BlockStatement",
"start":27,"end":29,"loc":{"start":{"line":1,"column":27},"end":{"line":1,"column":29}},
"body": [],
"directives": []
}
}
}
],
"directives": []
}
}
1 change: 1 addition & 0 deletions ...parser/test/fixtures/es2017/async-arrow/parenthesized-lhs-in-async-call-in-param/input.js
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@@ -0,0 +1 @@
async (x = async([(f) = []])) => {};
77 changes: 77 additions & 0 deletions ...ser/test/fixtures/es2017/async-arrow/parenthesized-lhs-in-async-call-in-param/output.json
View file
@@ -0,0 +1,77 @@
{
"type": "File",
"start":0,"end":36,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":36}},
"program": {
"type": "Program",
"start":0,"end":36,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":36}},
"sourceType": "script",
"interpreter": null,
"body": [
{
"type": "ExpressionStatement",
"start":0,"end":36,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":36}},
"expression": {
"type": "ArrowFunctionExpression",
"start":0,"end":35,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":35}},
"id": null,
"generator": false,
"async": true,
"params": [
{
"type": "AssignmentPattern",
"start":7,"end":28,"loc":{"start":{"line":1,"column":7},"end":{"line":1,"column":28}},
"left": {
"type": "Identifier",
"start":7,"end":8,"loc":{"start":{"line":1,"column":7},"end":{"line":1,"column":8},"identifierName":"x"},
"name": "x"
},
"right": {
"type": "CallExpression",
"start":11,"end":28,"loc":{"start":{"line":1,"column":11},"end":{"line":1,"column":28}},
"callee": {
"type": "Identifier",
"start":11,"end":16,"loc":{"start":{"line":1,"column":11},"end":{"line":1,"column":16},"identifierName":"async"},
"name": "async"
},
"arguments": [
{
"type": "ArrayExpression",
"start":17,"end":27,"loc":{"start":{"line":1,"column":17},"end":{"line":1,"column":27}},
"elements": [
{
"type": "AssignmentExpression",
"start":18,"end":26,"loc":{"start":{"line":1,"column":18},"end":{"line":1,"column":26}},
"operator": "=",
"left": {
"type": "Identifier",
"start":19,"end":20,"loc":{"start":{"line":1,"column":19},"end":{"line":1,"column":20},"identifierName":"f"},
"extra": {
"parenthesized": true,
"parenStart": 18
},
"name": "f"
},
"right": {
"type": "ArrayExpression",
"start":24,"end":26,"loc":{"start":{"line":1,"column":24},"end":{"line":1,"column":26}},
"elements": []
}
}
]
}
]
}
}
],
"body": {
"type": "BlockStatement",
"start":33,"end":35,"loc":{"start":{"line":1,"column":33},"end":{"line":1,"column":35}},
"body": [],
"directives": []
}
}
}
],
"directives": []
}
}

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