feat(minifier): minify string PropertyKey

crates/oxc_minifier/src/ast_passes/mod.rs

@@ -190,6 +190,10 @@ impl<'a> Traverse<'a> for LatePeepholeOptimizations {
     fn exit_call_expression(&mut self, expr: &mut CallExpression<'a>, ctx: &mut TraverseCtx<'a>) {
         self.x4_peephole_substitute_alternate_syntax.exit_call_expression(expr, ctx);
     }
+
+    fn exit_property_key(&mut self, key: &mut PropertyKey<'a>, ctx: &mut TraverseCtx<'a>) {
+        self.x4_peephole_substitute_alternate_syntax.exit_property_key(key, ctx);
+    }
 }
 
 // See `createPeepholeOptimizationsPass`

crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs

@@ -77,6 +77,10 @@ impl<'a> Traverse<'a> for PeepholeSubstituteAlternateSyntax {
         self.in_define_export = false;
     }
 
+    fn exit_property_key(&mut self, key: &mut PropertyKey<'a>, ctx: &mut TraverseCtx<'a>) {
+        self.try_compress_property_key(key, ctx);
+    }
+
     fn exit_expression(&mut self, expr: &mut Expression<'a>, ctx: &mut TraverseCtx<'a>) {
         let ctx = Ctx(ctx);
 
@@ -687,6 +691,39 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax {
     fn empty_array_literal(ctx: Ctx<'a, 'b>) -> Expression<'a> {
         Self::array_literal(ctx.ast.vec(), ctx)
     }
+
+    // https://github.com/swc-project/swc/blob/4e2dae558f60a9f5c6d2eac860743e6c0b2ec562/crates/swc_ecma_minifier/src/compress/pure/properties.rs
+    #[allow(clippy::cast_lossless)]
+    fn try_compress_property_key(&mut self, key: &mut PropertyKey<'a>, ctx: &mut TraverseCtx<'a>) {
+        use oxc_syntax::identifier::is_identifier_name;
+        let PropertyKey::StringLiteral(s) = key else { return };
+        if match ctx.parent() {
+            Ancestor::ObjectPropertyKey(key) => *key.computed(),
+            Ancestor::BindingPropertyKey(key) => *key.computed(),
+            Ancestor::MethodDefinitionKey(key) => *key.computed(),
+            Ancestor::PropertyDefinitionKey(key) => *key.computed(),
+            Ancestor::AccessorPropertyKey(key) => *key.computed(),
+            _ => true,
+        } {
+            return;
+        }
+        if is_identifier_name(&s.value) {
+            self.changed = true;
+            *key = PropertyKey::StaticIdentifier(
+                ctx.ast.alloc_identifier_name(s.span, s.value.clone()),
+            );
+        } else if (!s.value.starts_with('0') && !s.value.starts_with('+')) || s.value.len() <= 1 {
+            if let Ok(value) = s.value.parse::<u32>() {
+                self.changed = true;
+                *key = PropertyKey::NumericLiteral(ctx.ast.alloc_numeric_literal(
+                    s.span,
+                    value as f64,
+                    None,
+                    NumberBase::Decimal,
+                ));
+            }
+        }
+    }
 }
 
 /// Port from <https://github.com/google/closure-compiler/blob/v20240609/test/com/google/javascript/jscomp/PeepholeSubstituteAlternateSyntaxTest.java>
@@ -1137,4 +1174,10 @@ mod test {
         test("typeof foo !== `number`", "typeof foo != 'number'");
         test("`number` !== typeof foo", "'number' != typeof foo");
     }
+
+    #[test]
+    fn test_object_key() {
+        test("({ '0': _, 'a': _ })", "({ 0: _, a: _ })");
+        test_same("({ '1.1': _, '😊': _, 'a.a': _ })");
+    }
 }

tasks/minsize/minsize.snap

@@ -5,23 +5,23 @@ Original   | minified   | minified   | gzip       | gzip       | Fixture
 
 173.90 kB  | 60.22 kB   | 59.82 kB   | 19.49 kB   | 19.33 kB   | moment.js 
 
-287.63 kB  | 90.74 kB   | 90.07 kB   | 32.21 kB   | 31.95 kB   | jquery.js 
+287.63 kB  | 90.61 kB   | 90.07 kB   | 32.19 kB   | 31.95 kB   | jquery.js 
 
-342.15 kB  | 118.77 kB  | 118.14 kB  | 44.54 kB   | 44.37 kB   | vue.js    
+342.15 kB  | 118.76 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 
+544.10 kB  | 72.05 kB   | 72.48 kB   | 26.19 kB   | 26.20 kB   | lodash.js 
 
-555.77 kB  | 274.26 kB  | 270.13 kB  | 91.26 kB   | 90.80 kB   | d3.js     
+555.77 kB  | 274.04 kB  | 270.13 kB  | 91.20 kB   | 90.80 kB   | d3.js     
 
 1.01 MB    | 461.13 kB  | 458.89 kB  | 126.91 kB  | 126.71 kB  | bundle.min.js
 
-1.25 MB    | 657.23 kB  | 646.76 kB  | 164.23 kB  | 163.73 kB  | three.js  
+1.25 MB    | 656.86 kB  | 646.76 kB  | 164.20 kB  | 163.73 kB  | three.js  
 
-2.14 MB    | 735.67 kB  | 724.14 kB  | 181.09 kB  | 181.07 kB  | victory.js
+2.14 MB    | 735.43 kB  | 724.14 kB  | 181.01 kB  | 181.07 kB  | victory.js
 
-3.20 MB    | 1.01 MB    | 1.01 MB    | 332.35 kB  | 331.56 kB  | echarts.js
+3.20 MB    | 1.01 MB    | 1.01 MB    | 332.34 kB  | 331.56 kB  | echarts.js
 
-6.69 MB    | 2.38 MB    | 2.31 MB    | 495.33 kB  | 488.28 kB  | antd.js   
+6.69 MB    | 2.36 MB    | 2.31 MB    | 495.04 kB  | 488.28 kB  | antd.js   
 
-10.95 MB   | 3.51 MB    | 3.49 MB    | 910.94 kB  | 915.50 kB  | typescript.js
+10.95 MB   | 3.51 MB    | 3.49 MB    | 910.95 kB  | 915.50 kB  | typescript.js