diff --git a/crates/oxc_minifier/src/ast_passes/peephole_remove_dead_code.rs b/crates/oxc_minifier/src/ast_passes/peephole_remove_dead_code.rs index 30c5a6665876a..5e05b2220d912 100644 --- a/crates/oxc_minifier/src/ast_passes/peephole_remove_dead_code.rs +++ b/crates/oxc_minifier/src/ast_passes/peephole_remove_dead_code.rs @@ -146,7 +146,12 @@ impl<'a, 'b> PeepholeRemoveDeadCode { return; } if block.body.len() == 0 - && (ctx.parent().is_block_statement() || ctx.parent().is_program()) + && (ctx.parent().is_while_statement() + || ctx.parent().is_for_statement() + || ctx.parent().is_for_in_statement() + || ctx.parent().is_for_of_statement() + || ctx.parent().is_block_statement() + || ctx.parent().is_program()) { // Remove the block if it is empty and the parent is a block statement. *stmt = ctx.ast.statement_empty(SPAN); @@ -282,6 +287,53 @@ impl<'a, 'b> PeepholeRemoveDeadCode { Expression::ObjectExpression(object_expr) => { Self::try_fold_object_expression(object_expr, ctx) } + Expression::TemplateLiteral(template_lit) => { + template_lit.expressions.retain( + oxc_ecmascript::side_effects::MayHaveSideEffects::may_have_side_effects, + ); + + let mut expressions = ctx.ast.move_vec(&mut template_lit.expressions); + + if expressions.len() == 0 { + return Some(ctx.ast.statement_empty(SPAN)); + } else if expressions.len() == 1 { + return Some( + ctx.ast.statement_expression( + template_lit.span, + expressions.pop().unwrap(), + ), + ); + } + + return Some(ctx.ast.statement_expression( + template_lit.span, + ctx.ast.expression_from_sequence( + ctx.ast.sequence_expression(template_lit.span, expressions), + ), + )); + } + Expression::BinaryExpression(bin_expr) => { + let left = bin_expr.left.may_have_side_effects(); + let right = bin_expr.left.may_have_side_effects(); + + if left && right { + return None; + } + if !left && !right { + return Some(ctx.ast.statement_empty(SPAN)); + } + return Some(ctx.ast.statement_expression( + bin_expr.span, + ctx.ast.move_expression(if left { + &mut bin_expr.right + } else { + &mut bin_expr.left + }), + )); + } + Expression::FunctionExpression(function_expr) if function_expr.id.is_none() => { + Some(ctx.ast.statement_empty(SPAN)) + } _ => None, }) } @@ -503,22 +555,22 @@ mod test { fold("{if(false)if(false)if(false)foo(); {bar()}}", "bar()"); fold("{'hi'}", ""); - // fold("{x==3}", ""); - // fold("{`hello ${foo}`}", ""); - // fold("{ (function(){x++}) }", ""); - // fold_same("function f(){return;}"); - // fold("function f(){return 3;}", "function f(){return 3}"); + fold("{x==3}", ""); + fold("{`hello ${foo}`}", ""); + fold("{ (function(){x++}) }", ""); + fold_same("function f(){return;}"); + fold("function f(){return 3;}", "function f(){return 3}"); // fold_same("function f(){if(x)return; x=3; return; }"); // fold("{x=3;;;y=2;;;}", "x=3;y=2"); // Cases to test for empty block. // fold("while(x()){x}", "while(x());"); - // fold("while(x()){x()}", "while(x())x()"); + fold("while(x()){x()}", "while(x())x()"); // fold("for(x=0;x<100;x++){x}", "for(x=0;x<100;x++);"); // fold("for(x in y){x}", "for(x in y);"); // fold("for (x of y) {x}", "for(x of y);"); - // fold_same("for (let x = 1; x <10; x++ ) {}"); - // fold_same("for (var x = 1; x <10; x++ ) {}"); + fold("for (let x = 1; x <10; x++ ) {}", "for (let x = 1; x <10; x++ );"); + fold("for (var x = 1; x <10; x++ ) {}", "for (var x = 1; x <10; x++ );"); } #[test] diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap index e4407871e3aab..8ca5db9cef7bc 100644 --- a/tasks/minsize/minsize.snap +++ b/tasks/minsize/minsize.snap @@ -4,11 +4,11 @@ Original | Minified | esbuild | Gzip | esbuild 173.90 kB | 61.67 kB | 59.82 kB | 19.54 kB | 19.33 kB | moment.js -287.63 kB | 92.70 kB | 90.07 kB | 32.27 kB | 31.95 kB | jquery.js +287.63 kB | 92.70 kB | 90.07 kB | 32.26 kB | 31.95 kB | jquery.js 342.15 kB | 121.90 kB | 118.14 kB | 44.59 kB | 44.37 kB | vue.js -544.10 kB | 73.49 kB | 72.48 kB | 26.13 kB | 26.20 kB | lodash.js +544.10 kB | 73.48 kB | 72.48 kB | 26.12 kB | 26.20 kB | lodash.js 555.77 kB | 276.49 kB | 270.13 kB | 91.15 kB | 90.80 kB | d3.js @@ -16,7 +16,7 @@ Original | Minified | esbuild | Gzip | esbuild 1.25 MB | 662.86 kB | 646.76 kB | 164.00 kB | 163.73 kB | three.js -2.14 MB | 741.57 kB | 724.14 kB | 181.47 kB | 181.07 kB | victory.js +2.14 MB | 741.57 kB | 724.14 kB | 181.45 kB | 181.07 kB | victory.js 3.20 MB | 1.02 MB | 1.01 MB | 332.01 kB | 331.56 kB | echarts.js