fix(minifier): move drop_use_strict_directives_if_function_is_empty t…

…o PeepholeRemoveDeadCode
oxc-project · Dec 29, 2024 · ff48152 · ff48152
1 parent 48c015e
commit ff48152
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Showing 3 changed files with 28 additions and 16 deletions.
diff --git a/crates/oxc_minifier/src/ast_passes/mod.rs b/crates/oxc_minifier/src/ast_passes/mod.rs
@@ -146,6 +146,7 @@ impl<'a> Traverse<'a> for LatePeepholeOptimizations {
 
     fn exit_function_body(&mut self, body: &mut FunctionBody<'a>, ctx: &mut TraverseCtx<'a>) {
         self.x0_statement_fusion.exit_function_body(body, ctx);
+        self.x2_peephole_remove_dead_code.exit_function_body(body, ctx);
     }
 
     fn exit_statements(&mut self, stmts: &mut Vec<'a, Statement<'a>>, ctx: &mut TraverseCtx<'a>) {
@@ -232,6 +233,10 @@ impl<'a> Traverse<'a> for PeepholeOptimizations {
         self.x5_peephole_remove_dead_code.exit_program(program, ctx);
     }
 
+    fn exit_function_body(&mut self, body: &mut FunctionBody<'a>, ctx: &mut TraverseCtx<'a>) {
+        self.x5_peephole_remove_dead_code.exit_function_body(body, ctx);
+    }
+
     fn exit_statements(&mut self, stmts: &mut Vec<'a, Statement<'a>>, ctx: &mut TraverseCtx<'a>) {
         self.x2_peephole_minimize_conditions.exit_statements(stmts, ctx);
         self.x5_peephole_remove_dead_code.exit_statements(stmts, ctx);
@@ -300,6 +305,10 @@ impl<'a> Traverse<'a> for DeadCodeElimination {
         self.x2_peephole_remove_dead_code.exit_program(program, ctx);
     }
 
+    fn exit_function_body(&mut self, body: &mut FunctionBody<'a>, ctx: &mut TraverseCtx<'a>) {
+        self.x2_peephole_remove_dead_code.exit_function_body(body, ctx);
+    }
+
     fn exit_statements(&mut self, stmts: &mut Vec<'a, Statement<'a>>, ctx: &mut TraverseCtx<'a>) {
         self.x2_peephole_remove_dead_code.exit_statements(stmts, ctx);
     }

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
@@ -24,6 +24,10 @@ impl<'a> CompressorPass<'a> for PeepholeRemoveDeadCode {
 }
 
 impl<'a> Traverse<'a> for PeepholeRemoveDeadCode {
+    fn exit_function_body(&mut self, body: &mut FunctionBody<'a>, ctx: &mut TraverseCtx<'a>) {
+        Self::drop_use_strict_directives_if_function_is_empty(body, ctx);
+    }
+
     fn exit_statement(&mut self, stmt: &mut Statement<'a>, ctx: &mut TraverseCtx<'a>) {
         let ctx = Ctx(ctx);
         if let Some(new_stmt) = match stmt {
@@ -124,6 +128,16 @@ impl<'a, 'b> PeepholeRemoveDeadCode {
         }
     }
 
+    /// Drop `"use strict";` directives if the function is empty.
+    fn drop_use_strict_directives_if_function_is_empty(
+        body: &mut FunctionBody<'a>,
+        _ctx: &mut TraverseCtx<'a>,
+    ) {
+        if body.statements.is_empty() {
+            body.directives.retain(|directive| !directive.is_use_strict());
+        }
+    }
+
     /// Remove block from single line blocks
     /// `{ block } -> block`
     fn try_optimize_block(
@@ -436,6 +450,11 @@ mod test {
         test(js, expected);
     }
 
+    #[test]
+    fn use_strict() {
+        test("function foo() { 'use strict';}", "function foo() {}");
+    }
+
     #[test]
     fn test_fold_block() {
         fold("{{foo()}}", "foo()");

diff --git a/crates/oxc_minifier/src/ast_passes/remove_syntax.rs b/crates/oxc_minifier/src/ast_passes/remove_syntax.rs
@@ -29,10 +29,6 @@ impl<'a> Traverse<'a> for RemoveSyntax {
         Self::drop_use_strict_directives_in_function_body(body, ctx);
     }
 
-    fn exit_function_body(&mut self, body: &mut FunctionBody<'a>, ctx: &mut TraverseCtx<'a>) {
-        Self::drop_use_strict_directives_if_function_is_empty(body, ctx);
-    }
-
     fn exit_statements(&mut self, stmts: &mut Vec<'a, Statement<'a>>, _ctx: &mut TraverseCtx<'a>) {
         stmts.retain(|stmt| {
             !(matches!(stmt, Statement::EmptyStatement(_))
@@ -123,16 +119,6 @@ impl<'a> RemoveSyntax {
             body.directives.retain(|directive| !directive.is_use_strict());
         }
     }
-
-    /// Drop `"use strict";` directives if the function is empty.
-    fn drop_use_strict_directives_if_function_is_empty(
-        body: &mut FunctionBody<'a>,
-        _ctx: &mut TraverseCtx<'a>,
-    ) {
-        if body.statements.is_empty() {
-            body.directives.retain(|directive| !directive.is_use_strict());
-        }
-    }
 }
 
 #[cfg(test)]
@@ -205,7 +191,5 @@ mod test {
             "const Foo = class { foo() { 'use strict'; alert(1); } } ",
             "const Foo = class { foo() { alert(1); } } ",
         );
-
-        test_script("function foo() { 'use strict';}", "function foo() {}");
     }
 }