fix(minifier): handle sequence exprs when folding if to expr statement (#27939)

Handle sequence expressions when converting if statements to logical
expression statements:

`if (a(), !b); else c();` -> `a(), b && c();`
`if (a(), !b) c();` -> `a(), b || c();`

this change has been extracted from #27664

---------

Co-authored-by: Cameron <cameron.clark@hey.com>

crates/oxc_minifier/src/peephole/minimize_if_statement.rs

@@ -36,13 +36,12 @@ impl<'a> PeepholeOptimizations {
                 ctx.replace_statement_with(stmt, |stmt, ctx| {
                     let Statement::IfStatement(if_stmt) = stmt else { unreachable!() };
                     let IfStatement { test, span, .. } = if_stmt.unbox();
-                    let (op, a) = match test {
+                    let (op, a) = if Self::has_negated_result(&test) {
                         // `if (!a); else b();` => `a && b();`
-                        Expression::UnaryExpression(unary_expr) if unary_expr.operator.is_not() => {
-                            (LogicalOperator::And, unary_expr.unbox().argument)
-                        }
+                        (LogicalOperator::And, Self::minimize_not(span, test, ctx, true))
+                    } else {
                         // `if (a); else b();` => `a || b();`
-                        e => (LogicalOperator::Or, e),
+                        (LogicalOperator::Or, test)
                     };
                     let b = expr_stmt.unbox().expression;
                     let expr = Self::join_with_left_associative_op(span, op, a, b, ctx);
@@ -98,13 +97,12 @@ impl<'a> PeepholeOptimizations {
                 let Statement::IfStatement(if_stmt) = stmt else { unreachable!() };
                 let IfStatement { test, consequent, span, .. } = if_stmt.unbox();
                 let Statement::ExpressionStatement(b) = consequent else { unreachable!() };
-                let (op, a) = match test {
+                let (op, a) = if Self::has_negated_result(&test) {
                     // `if (!a) b();` => `a || b();`
-                    Expression::UnaryExpression(unary_expr) if unary_expr.operator.is_not() => {
-                        (LogicalOperator::Or, unary_expr.unbox().argument)
-                    }
+                    (LogicalOperator::Or, Self::minimize_not(span, test, ctx, true))
+                } else {
                     // `if (a)  b();` => `a && b();`
-                    e => (LogicalOperator::And, e),
+                    (LogicalOperator::And, test)
                 };
                 let b = b.unbox().expression;
                 let expr = Self::join_with_left_associative_op(span, op, a, b, ctx);

crates/oxc_minifier/src/peephole/minimize_not_expression.rs

@@ -245,4 +245,17 @@ impl<'a> PeepholeOptimizations {
         expr.operator = inverse;
         ctx.notice_change();
     }
+
+    pub fn has_negated_result(test: &Expression<'a>) -> bool {
+        match test {
+            // `(_, !a)`, `(_, a)`
+            Expression::SequenceExpression(seq) => {
+                Self::last_expression_in_sequence(seq).is_some_and(Self::has_negated_result)
+            }
+            // `!a`
+            Expression::UnaryExpression(unary_expr) if unary_expr.operator.is_not() => true,
+            // `a`
+            _ => false,
+        }
+    }
 }

crates/oxc_minifier/tests/peephole/esbuild.rs

@@ -218,11 +218,8 @@ fn js_parser_test() {
     );
     test("while (x) { if (y) continue; z(); }", "for (; x; ) y || z();");
     test("while (x) { if (y) continue; else z(); w(); }", "for (; x; ) y || (z(), w());");
-    test("while (x) { t(); if (y) continue; z(); }", "for (; x; ) t(), !y && z();");
-    test(
-        "while (x) { t(); if (y) continue; else z(); w(); }",
-        "for (; x; ) t(), !y && (z(), w());",
-    );
+    test("while (x) { t(); if (y) continue; z(); }", "for (; x; ) t(), y || z();");
+    test("while (x) { t(); if (y) continue; else z(); w(); }", "for (; x; ) t(), y || (z(), w());");
     test("while (x) { debugger; if (y) continue; z(); }", "for (; x; ) { debugger; y || z(); }");
     test(
         "while (x) { debugger; if (y) continue; else z(); w(); }",
@@ -1153,10 +1150,10 @@ fn test_minimize_exit_statements() {
     test("if (a) return b; else return c; return d;", "return a ? b : c;");
     test("function x() { if (y) return; z(); }", "function x() { y || z();}");
     test("function x() { if (y) return; else z(); w(); }", "function x() { y || (z(), w());}");
-    test("function x() { t(); if (y) return; z(); }", "function x() { t(), !y && z();}");
+    test("function x() { t(); if (y) return; z(); }", "function x() { t(), y || z();}");
     test(
         "function x() { t(); if (y) return; else z(); w(); }",
-        "function x() { t(), !y && (z(), w());}",
+        "function x() { t(), y || (z(), w());}",
     );
     test("function x() { debugger; if (y) return; z(); }", "function x() { debugger; y || z();}");
     test(

crates/oxc_minifier/tests/peephole/minimize_exit_points.rs

@@ -177,7 +177,7 @@ fn test_while_continue_optimization() {
     test("while(true){if(a()){continue;}else{continue;} b();}", "for(;;)a();");
     test(
         "while(true){d();if(a()){continue;}else if(b()){c();continue;}else{continue;}}",
-        "for(;;)d(),!a()&&b()&&c()",
+        "for(;;)d(),a()||b()&&c()",
     );
 
     test("while(true)while(a())continue;", "for(;;)for(;a();)continue;"); // for(;;)for(;a(););

crates/oxc_minifier/tests/peephole/minimize_if_statement.rs

@@ -88,7 +88,11 @@ fn test_minimize_if() {
     test("function f(){if(!a)b();else return c;}", "function f(){if(!a)b();else return c;}");
     test("function f(){if(a)return c;else b();}", "function f(){if(a)return c;b();}");
     test("function f(){if((a(),b)){}else c();}", "function f(){a(),b||c();}");
-    test("function f(){if(a(),!(b||c)){}else d();}", "function f(){a(),!(b||c)||d();}");
+    test("function f(){if(a(),b){}else c();}", "function f(){a(),b||c();}");
+    test("function f(){if(a(),!b){}else c();}", "function f(){a(),b&&c();}");
+    test("function f(){if(a(),!b)c();}", "function f(){a(),b||c();}");
+    test("function f(){if(!a(),b)c();}", "function f(){a(),b&&c();}");
+    test("function f(){if(a(),!(b||c)){}else d();}", "function f(){a(),(b||c)&&d();}");
 
     test("function f(a){if(a){}}", "function f(a){}");
     test("function f(a){if(a);}", "function f(a){}");

tasks/minsize/minsize.snap

@@ -5,7 +5,7 @@ Original   | minified   | minified   | gzip       | gzip       | Iterations | Fi
 
 173.90 kB  | 55.49 kB   | 59.82 kB   | 18.78 kB   | 19.33 kB   |          2 | moment.js
 
-287.63 kB  | 88.94 kB   | 90.07 kB   | 30.84 kB   | 31.95 kB   |          2 | jquery.js
+287.63 kB  | 88.94 kB   | 90.07 kB   | 30.83 kB   | 31.95 kB   |          2 | jquery.js
 
 342.15 kB  | 114.75 kB  | 118.14 kB  | 42.68 kB   | 44.37 kB   |          2 | vue.js
 
@@ -17,11 +17,11 @@ Original   | minified   | minified   | gzip       | gzip       | Iterations | Fi
 
 1.25 MB    | 634.21 kB  | 646.76 kB  | 158.43 kB  | 163.73 kB  |          2 | three.js
 
-2.14 MB    | 707.58 kB  | 724.14 kB  | 160.05 kB  | 181.07 kB  |          2 | victory.js
+2.14 MB    | 707.55 kB  | 724.14 kB  | 160.05 kB  | 181.07 kB  |          2 | victory.js
 
 3.20 MB    | 958.38 kB  | 1.01 MB    | 316.95 kB  | 331.56 kB  |          2 | echarts.js
 
-6.69 MB    | 2.12 MB    | 2.31 MB    | 453.41 kB  | 488.28 kB  |          4 | antd.js
+6.69 MB    | 2.12 MB    | 2.31 MB    | 453.37 kB  | 488.28 kB  |          4 | antd.js
 
-10.95 MB   | 3.31 MB    | 3.49 MB    | 849.76 kB  | 915.50 kB  |          4 | typescript.js
+10.95 MB   | 3.31 MB    | 3.49 MB    | 849.75 kB  | 915.50 kB  |          4 | typescript.js
 

tasks/track_memory_allocations/allocs_minifier.yaml

@@ -3,22 +3,22 @@ checker.ts:
   sys allocs: 40
   sys reallocs: 5
   sys deallocs: 40
-  sys alloc bytes: 14996287 # 15.00 MB
+  sys alloc bytes: 14995460 # 15.00 MB
   sys peak growth: 10169560 # 10.17 MB
   arena allocs: 56228
   arena reallocs: 5084
-  arena size: 16501168 # 16.50 MB
+  arena size: 16501008 # 16.50 MB
 
 App.tsx:
   file size: 415342 # 415.34 kB
   sys allocs: 35
   sys reallocs: 8
   sys deallocs: 35
-  sys alloc bytes: 2128539 # 2.13 MB
+  sys alloc bytes: 2126572 # 2.13 MB
   sys peak growth: 1612427 # 1.61 MB
   arena allocs: 7729
   arena reallocs: 920
-  arena size: 2782336 # 2.78 MB
+  arena size: 2782328 # 2.78 MB
 
 RadixUIAdoptionSection.jsx:
   file size: 2520 # 2.52 kB
@@ -36,40 +36,40 @@ pdf.mjs:
   sys allocs: 1933
   sys reallocs: 205
   sys deallocs: 1933
-  sys alloc bytes: 5313795 # 5.31 MB
+  sys alloc bytes: 5287933 # 5.29 MB
   sys peak growth: 3693355 # 3.69 MB
-  arena allocs: 19581
+  arena allocs: 19582
   arena reallocs: 2574
-  arena size: 5727264 # 5.73 MB
+  arena size: 5726904 # 5.73 MB
 
 antd.js:
   file size: 6686316 # 6.69 MB
   sys allocs: 155
   sys reallocs: 52
   sys deallocs: 155
-  sys alloc bytes: 29973448 # 29.97 MB
+  sys alloc bytes: 29960368 # 29.96 MB
   sys peak growth: 19934725 # 19.93 MB
-  arena allocs: 175847
+  arena allocs: 175842
   arena reallocs: 34169
-  arena size: 44039472 # 44.04 MB
+  arena size: 44039296 # 44.04 MB
 
 binder.ts:
   file size: 193077 # 193.08 kB
   sys allocs: 25
   sys reallocs: 1
   sys deallocs: 25
-  sys alloc bytes: 963008 # 963.01 kB
+  sys alloc bytes: 962926 # 962.93 kB
   sys peak growth: 657404 # 657.40 kB
   arena allocs: 2930
   arena reallocs: 244
-  arena size: 1092424 # 1.09 MB
+  arena size: 1092336 # 1.09 MB
 
 kitchen-sink.tsx:
   file size: 732898 # 732.90 kB
   sys allocs: 354
   sys reallocs: 174
   sys deallocs: 354
-  sys alloc bytes: 5304252 # 5.30 MB
+  sys alloc bytes: 5284342 # 5.28 MB
   sys peak growth: 3707425 # 3.71 MB
   arena allocs: 31100
   arena reallocs: 3011