diff --git a/crates/oxc_minifier/src/ast_passes/peephole_fold_constants.rs b/crates/oxc_minifier/src/ast_passes/peephole_fold_constants.rs index 82f7e50cc766e..dbff2b5eb207b 100644 --- a/crates/oxc_minifier/src/ast_passes/peephole_fold_constants.rs +++ b/crates/oxc_minifier/src/ast_passes/peephole_fold_constants.rs @@ -241,7 +241,6 @@ impl<'a, 'b> PeepholeFoldConstants { BinaryOperator::ShiftLeft | BinaryOperator::ShiftRight | BinaryOperator::ShiftRightZeroFill - | BinaryOperator::Addition | BinaryOperator::Subtraction | BinaryOperator::Division | BinaryOperator::Remainder @@ -249,6 +248,7 @@ impl<'a, 'b> PeepholeFoldConstants { | BinaryOperator::Exponential => { ctx.eval_binary_expression(e).map(|v| ctx.value_to_expr(e.span, v)) } + BinaryOperator::Addition => Self::try_fold_add(e, ctx), BinaryOperator::BitwiseAnd | BinaryOperator::BitwiseOR | BinaryOperator::BitwiseXOR => { if let Some(v) = ctx.eval_binary_expression(e) { return Some(ctx.value_to_expr(e.span, v)); @@ -260,6 +260,27 @@ impl<'a, 'b> PeepholeFoldConstants { } } + // Simplified version of `tryFoldAdd` from closure compiler. + fn try_fold_add(e: &mut BinaryExpression<'a>, ctx: Ctx<'a, 'b>) -> Option> { + if let Some(v) = ctx.eval_binary_expression(e) { + return Some(ctx.value_to_expr(e.span, v)); + } + debug_assert_eq!(e.operator, BinaryOperator::Addition); + // a + 'b' + 'c' -> a + 'bc' + if let Expression::BinaryExpression(left_binary_expr) = &mut e.left { + if let Expression::StringLiteral(left_str) = &left_binary_expr.right { + if let Expression::StringLiteral(right_str) = &e.right { + let span = Span::new(left_str.span.start, right_str.span.end); + let value = left_str.value.to_string() + right_str.value.as_str(); + let right = ctx.ast.expression_string_literal(span, value, None); + let left = ctx.ast.move_expression(&mut left_binary_expr.left); + return Some(ctx.ast.expression_binary(e.span, left, e.operator, right)); + } + } + } + None + } + fn try_fold_left_child_op( e: &mut BinaryExpression<'a>, ctx: Ctx<'a, '_>, @@ -1318,7 +1339,7 @@ mod test { } #[test] - fn test_fold_bit_shift() { + fn test_fold_bit_shifts() { test("x = 1 << 0", "x=1"); test("x = -1 << 0", "x=-1"); test("x = 1 << 1", "x=2"); @@ -1366,6 +1387,49 @@ mod test { test("8589934593 >>> 0", "1"); } + #[test] + fn test_string_add() { + test("x = 'a' + 'bc'", "x = 'abc'"); + test("x = 'a' + 5", "x = 'a5'"); + test("x = 5 + 'a'", "x = '5a'"); + // test("x = 'a' + 5n", "x = 'a5n'"); + // test("x = 5n + 'a'", "x = '5na'"); + test("x = 'a' + ''", "x = 'a'"); + test("x = 'a' + foo()", "x = 'a'+foo()"); + test("x = foo() + 'a' + 'b'", "x = foo()+'ab'"); + test("x = (foo() + 'a') + 'b'", "x = foo()+'ab'"); // believe it! + test("x = foo() + 'a' + 'b' + 'cd' + bar()", "x = foo()+'abcd'+bar()"); + test("x = foo() + 2 + 'b'", "x = foo()+2+\"b\""); // don't fold! + + // test("x = foo() + 'a' + 2", "x = foo()+\"a2\""); + test("x = '' + null", "x = 'null'"); + test("x = true + '' + false", "x = 'truefalse'"); + // test("x = '' + []", "x = ''"); + // test("x = foo() + 'a' + 1 + 1", "x = foo() + 'a11'"); + test("x = 1 + 1 + 'a'", "x = '2a'"); + test("x = 1 + 1 + 'a'", "x = '2a'"); + test("x = 'a' + (1 + 1)", "x = 'a2'"); + // test("x = '_' + p1 + '_' + ('' + p2)", "x = '_' + p1 + '_' + p2"); + // test("x = 'a' + ('_' + 1 + 1)", "x = 'a_11'"); + // test("x = 'a' + ('_' + 1) + 1", "x = 'a_11'"); + // test("x = 1 + (p1 + '_') + ('' + p2)", "x = 1 + (p1 + '_') + p2"); + // test("x = 1 + p1 + '_' + ('' + p2)", "x = 1 + p1 + '_' + p2"); + // test("x = 1 + 'a' + p1", "x = '1a' + p1"); + // test("x = (p1 + (p2 + 'a')) + 'b'", "x = (p1 + (p2 + 'ab'))"); + // test("'a' + ('b' + p1) + 1", "'ab' + p1 + 1"); + // test("x = 'a' + ('b' + p1 + 'c')", "x = 'ab' + (p1 + 'c')"); + test_same("x = 'a' + (4 + p1 + 'a')"); + test_same("x = p1 / 3 + 4"); + test_same("foo() + 3 + 'a' + foo()"); + test_same("x = 'a' + ('b' + p1 + p2)"); + test_same("x = 1 + ('a' + p1)"); + test_same("x = p1 + '' + p2"); + test_same("x = 'a' + (1 + p1)"); + test_same("x = (p2 + 'a') + (1 + p1)"); + test_same("x = (p2 + 'a') + (1 + p1 + p2)"); + test_same("x = (p2 + 'a') + (1 + (p1 + p2))"); + } + #[test] fn test_fold_arithmetic() { test("x = 10 + 20", "x = 30"); diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap index 1df8712007678..df2d1af01df2b 100644 --- a/tasks/minsize/minsize.snap +++ b/tasks/minsize/minsize.snap @@ -1,13 +1,13 @@ | Oxc | ESBuild | Oxc | ESBuild | Original | minified | minified | gzip | gzip | Fixture ------------------------------------------------------------------------------------- -72.14 kB | 23.74 kB | 23.70 kB | 8.62 kB | 8.54 kB | react.development.js +72.14 kB | 23.74 kB | 23.70 kB | 8.61 kB | 8.54 kB | react.development.js 173.90 kB | 60.22 kB | 59.82 kB | 19.49 kB | 19.33 kB | moment.js -287.63 kB | 90.76 kB | 90.07 kB | 32.22 kB | 31.95 kB | jquery.js +287.63 kB | 90.74 kB | 90.07 kB | 32.21 kB | 31.95 kB | jquery.js -342.15 kB | 119.00 kB | 118.14 kB | 44.66 kB | 44.37 kB | vue.js +342.15 kB | 118.77 kB | 118.14 kB | 44.54 kB | 44.37 kB | vue.js 544.10 kB | 72.53 kB | 72.48 kB | 26.23 kB | 26.20 kB | lodash.js @@ -17,11 +17,11 @@ Original | minified | minified | gzip | gzip | Fixture 1.25 MB | 657.23 kB | 646.76 kB | 164.23 kB | 163.73 kB | three.js -2.14 MB | 735.70 kB | 724.14 kB | 181.11 kB | 181.07 kB | victory.js +2.14 MB | 735.67 kB | 724.14 kB | 181.09 kB | 181.07 kB | victory.js 3.20 MB | 1.01 MB | 1.01 MB | 332.35 kB | 331.56 kB | echarts.js -6.69 MB | 2.38 MB | 2.31 MB | 495.34 kB | 488.28 kB | antd.js +6.69 MB | 2.38 MB | 2.31 MB | 495.33 kB | 488.28 kB | antd.js 10.95 MB | 3.51 MB | 3.49 MB | 910.94 kB | 915.50 kB | typescript.js