sapphi-red 814da55f81 feat(minifier): compress x = x || 1 to x ||= 1 (#8368) ... The simplified version of the evaluation of `a = a || b` is: > AssignmentExpression : LeftHandSideExpression = LogicalORExpression || LogicalANDExpression > 1. Let lRef be ? Evaluation of LeftHandSideExpression. > 2. Let llRef be ? Evaluation of LogicalORExpression. > 3. Let llVal be ? GetValue(llRef). > 4. If ToBoolean(llVal) is true > a. Perform ? PutValue(lRef, llVal). > b. return llVal. > 5. Let lrRef be ? Evaluation of LogicalANDExpression. > 6. Let rRef be ? GetValue(lrRef). > 7. Let rVal be ? GetValue(rRef). [Note GetValue(rRef) returns rRef itself] > 8. Perform ? PutValue(lRef, rVal). > 9. Return rVal. The simplified version of the evaluation of `a ||= b` is: > AssignmentExpression : LeftHandSideExpression ||= AssignmentExpression > 1. Let lRef be ? Evaluation of LeftHandSideExpression. > 2. Let lVal be ? GetValue(lRef). > 3. If ToBoolean(lVal) is true, return lVal. > 4. Let rRef be ? Evaluation of AssignmentExpression. > 5. Let rVal be ? GetValue(rRef). > 6. Perform ? PutValue(lRef, rVal). > 7. Return rVal. The difference of these is that - the evaluation of `a` is done twice for `a = a || b`, one with `1. Let lRef be ? Evaluation of LeftHandSideExpression` and one with `2. Let llRef be ? Evaluation of LogicalORExpression.`. This is same with #8366, #8367. - `PutValue(lRef, llVal)` is performed when `ToBoolean(lVal)` is `true`. So `x = x || 1` can be compressed to `x ||= 1` when the conditions written in #8366 are met and `PutValue(lRef, llVal)` does not have a side effect. When `a` is a non-global identifier (and not a reference created by a `with` statement), these conditions are met. **References** - [Spec of `||`](https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-binary-logical-operators-runtime-semantics-evaluation) - [Spec of `=` / `||=`](https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-binary-logical-operators-runtime-semantics-evaluation)		2025-01-09 03:47:12 +00:00
..
ast_tools	refactor(ast)!: no unneccesary trailing underscores on AstBuilder method names (#8283)	2025-01-06 15:09:05 +00:00
benchmark	refactor(linter): refactor LintBuilder to prep for nested configs (#8034)	2025-01-05 04:08:26 +00:00
common	chore(doc): replace main/master to tag/commit to make the url always accessible (#7298)	2024-11-16 21:00:30 +08:00
compat_data	refactor(global): sort imports (#7883)	2024-12-14 15:07:21 +00:00
coverage	fix(transformer/private-methods): create brand binding var in hoist scope (#8361)	2025-01-09 03:17:38 +00:00
javascript_globals	feat(linter)!: sync sindresorhus/globals; removed Object.prototype properties from builtin and es* globals (#6991)	2024-10-29 04:13:20 +00:00
lint_rules	fix(tasks/lint_rules): sync unicorn rules with eslint rules (#8224)	2025-01-03 11:39:51 +08:00
minsize	feat(minifier): compress x = x || 1 to x ||= 1 (#8368)	2025-01-09 03:47:12 +00:00
prettier_conformance	refactor(prettier): Update tasks/prettier to correctly handle snapshots (#8337)	2025-01-08 17:10:30 +08:00
rulegen	test(linter): use plugin name instead of category for finding rule (#8353)	2025-01-09 10:48:11 +08:00
transform_checker	perf(semantic): allocate UnresolvedReferences in allocator (#8046)	2024-12-20 15:18:16 +00:00
transform_conformance	fix(transformer/private-methods): no temp var for class when unused private methods (#8360)	2025-01-09 03:17:37 +00:00
website	docs(tasks/website): add legend for fixable column (#7945)	2024-12-17 10:25:11 +08:00