feat(minifier): minimize do{}while(true) -> do;while(true)

oxc-project · Jan 7, 2025 · fce5725 · fce5725
1 parent e3ff81e
commit fce5725
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Showing 3 changed files with 35 additions and 21 deletions.
diff --git a/crates/oxc_codegen/src/gen.rs b/crates/oxc_codegen/src/gen.rs
@@ -471,17 +471,21 @@ impl Gen for DoWhileStatement<'_> {
     fn gen(&self, p: &mut Codegen, ctx: Context) {
         p.add_source_mapping(self.span);
         p.print_indent();
-        p.print_str("do ");
-        if let Statement::BlockStatement(block) = &self.body {
-            p.print_block_statement(block, ctx);
-            p.print_soft_space();
-        } else {
-            p.print_soft_newline();
-            p.indent();
-            self.body.print(p, ctx);
-            p.print_semicolon_if_needed();
-            p.dedent();
-            p.print_indent();
+        p.print_str("do");
+        match &self.body {
+            Statement::BlockStatement(block) => {
+                p.print_block_statement(block, ctx);
+                p.print_soft_space();
+            }
+            Statement::EmptyStatement(s) => s.print(p, ctx),
+            _ => {
+                p.print_soft_newline();
+                p.indent();
+                self.body.print(p, ctx);
+                p.print_semicolon_if_needed();
+                p.dedent();
+                p.print_indent();
+            }
         }
         p.print_str("while");
         p.print_soft_space();

diff --git a/crates/oxc_codegen/tests/integration/unit.rs b/crates/oxc_codegen/tests/integration/unit.rs
@@ -87,6 +87,12 @@ fn for_stmt() {
     );
 }
 
+#[test]
+fn do_while_stmt() {
+    test("do ; while (true);", "do;\nwhile (true);\n");
+    test_minify("do ; while (true);", "do;while(true);");
+}
+
 #[test]
 fn if_stmt() {
     test(

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
@@ -140,16 +140,19 @@ impl<'a, 'b> PeepholeRemoveDeadCode {
         if stmt.body.len() == 1 && !stmt.body[0].is_declaration() {
             return Some(stmt.body.remove(0));
         }
-        if stmt.body.len() == 0
-            && (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.
-            return Some(ctx.ast.statement_empty(stmt.span));
+        if stmt.body.len() == 0 {
+            let parent = ctx.parent();
+            if parent.is_while_statement()
+                || parent.is_do_while_statement()
+                || parent.is_for_statement()
+                || parent.is_for_in_statement()
+                || parent.is_for_of_statement()
+                || parent.is_block_statement()
+                || parent.is_program()
+            {
+                // Remove the block if it is empty and the parent is a block statement.
+                return Some(ctx.ast.statement_empty(stmt.span));
+            }
         }
         None
     }
@@ -563,6 +566,7 @@ mod test {
         // fold("for (x of y) {x}", "for(x of y);");
         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++ );");
+        fold("do { } while (true)", "do;while(true)");
     }
 
     #[test]