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https://github.com/danbulant/oxc
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ec88c68c28
Compress `a || (a = b)` to `a ||= b` and for other logical operators that are possible to. I didn't find other minifiers doing this, but this is safe for identifiers. [Quoting MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment#description): > Logical OR assignment short-circuits, meaning that `x ||= y` is equivalent to `x || (x = y)`, except that the expression x is only evaluated once. I actually checked the spec and the only difference was that `Let lRef be ? Evaluation of LeftHandSideExpression` was done twice. Evaluating an IdentifierReference is idempotent so it should be safe to do this compression. References: - [Spec of `&&=`](https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-assignment-operators:~:text=Return%20r.-,AssignmentExpression,7.%20Return%20rVal.,-AssignmentExpression) - [Spec of `=`](https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#prod-AssignmentExpression:~:text=Runtime%20Semantics%3A%20Evaluation-,AssignmentExpression,6.%20Return%20rVal.,-AssignmentExpression) - [Spec of `&&`](https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-binary-logical-operators:~:text=Runtime%20Semantics%3A%20Evaluation-,LogicalANDExpression,5.%20Return%20%3F%C2%A0GetValue(rRef).,-LogicalORExpression) I think this is safe for `a.b || (a.b = foo)` as well because the number of `GetValue` and `SetValue` does not change, but I didn't include that in this PR. |
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| .. | ||
| oxc | ||
| oxc_allocator | ||
| oxc_ast | ||
| oxc_ast_macros | ||
| oxc_cfg | ||
| oxc_codegen | ||
| oxc_data_structures | ||
| oxc_diagnostics | ||
| oxc_ecmascript | ||
| oxc_estree | ||
| oxc_isolated_declarations | ||
| oxc_language_server | ||
| oxc_linter | ||
| oxc_macros | ||
| oxc_mangler | ||
| oxc_minifier | ||
| oxc_napi | ||
| oxc_parser | ||
| oxc_prettier | ||
| oxc_regular_expression | ||
| oxc_semantic | ||
| oxc_span | ||
| oxc_syntax | ||
| oxc_transformer | ||
| oxc_traverse | ||
| oxc_wasm | ||