Parenthesize export assignments if needed #19590
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src/compiler/factory.ts
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| @@ -1982,7 +1982,7 @@ namespace ts { | |||
| node.decorators = asNodeArray(decorators); | |||
| node.modifiers = asNodeArray(modifiers); | |||
| node.isExportEquals = isExportEquals; | |||
| node.expression = expression; | |||
| node.expression = parenthesizeBinaryOperand(SyntaxKind.EqualsToken, expression, /*isLeftSideOfBinary*/ false, /*leftOperand*/ undefined); | |||
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As far as I can tell, export default <expr> binds as tightly as export = <expr>, so this seems appropriate.
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Actually, I think export default may need its own parenthesization logic. Per the spec, export default accepts AssigmentExpression but has a lookahead restriction for function, async function, and class.
Basically, that means you need to parenthesize in the following cases:
- BinaryExpression of CommaToken
- CommaList (synthetic list of multiple comma expressions)
- FunctionExpression
- ClassExpression
src/compiler/factory.ts
Outdated
| @@ -1982,7 +1982,7 @@ namespace ts { | |||
| node.decorators = asNodeArray(decorators); | |||
| node.modifiers = asNodeArray(modifiers); | |||
| node.isExportEquals = isExportEquals; | |||
| node.expression = expression; | |||
| node.expression = parenthesizeBinaryOperand(SyntaxKind.EqualsToken, expression, /*isLeftSideOfBinary*/ false, /*leftOperand*/ undefined); | |||
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Actually, I think export default may need its own parenthesization logic. Per the spec, export default accepts AssigmentExpression but has a lookahead restriction for function, async function, and class.
Basically, that means you need to parenthesize in the following cases:
- BinaryExpression of CommaToken
- CommaList (synthetic list of multiple comma expressions)
- FunctionExpression
- ClassExpression
| export function parenthesizeDefaultExpression(e: Expression) { | ||
| const check = skipPartiallyEmittedExpressions(e); | ||
| return (check.kind === SyntaxKind.ClassExpression || | ||
| check.kind === SyntaxKind.FunctionExpression || |
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Is parenthesizing FunctionExpression and ClassExpression enough to stop them from being seen as HoistableDeclaration/ClassDeclaration? 🤔
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Yes. Once you add parens, you are no longer in a declaration.
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Should be. Anything that doesn't work that way is parsing incorrectly.
Fixes #19574.