feat(minifier): minimize not !(x === undefined) -> x !== undefined (

#8429)
oxc-project · Jan 11, 2025 · dab7a51 · dab7a51
1 parent 7f69561
commit dab7a51
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Showing 2 changed files with 17 additions and 7 deletions.
diff --git a/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs b/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs
@@ -117,14 +117,21 @@ impl<'a> PeepholeMinimizeConditions {
         expr: &mut UnaryExpression<'a>,
         ctx: &mut TraverseCtx<'a>,
     ) -> Option<Expression<'a>> {
-        if expr.operator.is_not() {
-            if let Expression::UnaryExpression(e1) = &mut expr.argument {
-                if e1.operator.is_not() && ValueType::from(&e1.argument).is_boolean() {
-                    return Some(ctx.ast.move_expression(&mut e1.argument));
-                }
+        if !expr.operator.is_not() {
+            return None;
+        }
+        match &mut expr.argument {
+            Expression::UnaryExpression(e)
+                if e.operator.is_not() && ValueType::from(&e.argument).is_boolean() =>
+            {
+                Some(ctx.ast.move_expression(&mut e.argument))
             }
+            Expression::BinaryExpression(e) if e.operator.is_equality() => {
+                e.operator = e.operator.equality_inverse_operator().unwrap();
+                Some(ctx.ast.move_expression(&mut expr.argument))
+            }
+            _ => None,
         }
-        None
     }
 
     fn try_minimize_if(
@@ -1968,6 +1975,9 @@ mod test {
 
     #[test]
     fn minimize_nots_with_binary_expressions() {
+        test("!(x === undefined)", "x !== undefined");
+        test("!(typeof(x) === 'undefined')", "typeof x != 'undefined'");
+        test("!(x === void 0)", "x !== void 0");
         test("!!delete x.y", "delete x.y");
         test("!!!delete x.y", "!delete x.y");
         test("!!!!delete x.y", "delete x.y");

diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap
@@ -1,7 +1,7 @@
            | Oxc        | ESBuild    | Oxc        | ESBuild    |
 Original   | minified   | minified   | gzip       | gzip       | Fixture
 -------------------------------------------------------------------------------------
-72.14 kB   | 23.71 kB   | 23.70 kB   | 8.61 kB    | 8.54 kB    | react.development.js
+72.14 kB   | 23.70 kB   | 23.70 kB   | 8.60 kB    | 8.54 kB    | react.development.js
 
 173.90 kB  | 59.79 kB   | 59.82 kB   | 19.41 kB   | 19.33 kB   | moment.js