From 8c8b5fa9bec24138fec13a75239bd949a2bc4700 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E7=BF=A0=20/=20green?= Date: Mon, 20 Jan 2025 14:34:46 +0900 Subject: [PATCH] fix(minifier): avoid minifing `String(a)` into `"" + a` for symbols (#8612) We shouldn't change `String(a)` into `"" + a` if `a` can be a Symbol. `String(Symbol())` does not throw an error, but `"" + Symbol()` does. **References** - [Spec of `ToString` (called for `"" + variable`)](https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tostring) - [Spec of `String(a)`](https://tc39.es/ecma262/multipage/text-processing.html#sec-string-constructor-string-value) --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com> --- .../ast_passes/peephole_substitute_alternate_syntax.rs | 6 +++--- tasks/minsize/minsize.snap | 10 +++++----- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs b/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs index 68ee28ca4..aec49e14c 100644 --- a/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs +++ b/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs @@ -866,9 +866,7 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax { None => Some(ctx.ast.expression_string_literal(span, "", None)), // `String(a)` -> `'' + (a)` Some(arg) => { - if !matches!(arg, Expression::Identifier(_) | Expression::CallExpression(_)) - && !arg.is_literal() - { + if !arg.is_literal() { return None; } Some(ctx.ast.expression_binary( @@ -1973,6 +1971,8 @@ mod test { // Don't fold the existence check to preserve behavior test_same("var a = String?.('hello')"); + test_same("var s = Symbol();var a = String(s);"); + test_same("var a = String('hello', bar());"); test_same("var a = String({valueOf: function() { return 1; }});"); } diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap index 33dbadc62..6a8d41aaf 100644 --- a/tasks/minsize/minsize.snap +++ b/tasks/minsize/minsize.snap @@ -7,21 +7,21 @@ Original | minified | minified | gzip | gzip | Fixture 287.63 kB | 90.08 kB | 90.07 kB | 32.03 kB | 31.95 kB | jquery.js -342.15 kB | 118.14 kB | 118.14 kB | 44.45 kB | 44.37 kB | vue.js +342.15 kB | 118.19 kB | 118.14 kB | 44.45 kB | 44.37 kB | vue.js 544.10 kB | 71.76 kB | 72.48 kB | 26.15 kB | 26.20 kB | lodash.js 555.77 kB | 272.90 kB | 270.13 kB | 90.90 kB | 90.80 kB | d3.js -1.01 MB | 460.15 kB | 458.89 kB | 126.77 kB | 126.71 kB | bundle.min.js +1.01 MB | 460.18 kB | 458.89 kB | 126.78 kB | 126.71 kB | bundle.min.js -1.25 MB | 652.88 kB | 646.76 kB | 163.54 kB | 163.73 kB | three.js +1.25 MB | 652.90 kB | 646.76 kB | 163.54 kB | 163.73 kB | three.js -2.14 MB | 724.05 kB | 724.14 kB | 179.94 kB | 181.07 kB | victory.js +2.14 MB | 724.06 kB | 724.14 kB | 179.94 kB | 181.07 kB | victory.js 3.20 MB | 1.01 MB | 1.01 MB | 332.01 kB | 331.56 kB | echarts.js -6.69 MB | 2.31 MB | 2.31 MB | 492.51 kB | 488.28 kB | antd.js +6.69 MB | 2.31 MB | 2.31 MB | 492.53 kB | 488.28 kB | antd.js 10.95 MB | 3.49 MB | 3.49 MB | 907.24 kB | 915.50 kB | typescript.js