Remove unnecessary parentheses around class expression (#14409)

changelog_unreleased/javascript/14409.md

@@ -0,0 +1,23 @@
+#### Remove unnecessary parentheses around class expression (#14409 by @fisker)
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+call(
+  @dec class {}
+);
+
+// Prettier stable
+call(
+  (
+    @dec
+    class {}
+  )
+);
+
+// Prettier main
+call(
+  @dec
+  class {},
+);
+```

src/language-js/needs-parens.js

@@ -155,7 +155,8 @@ function needsParens(path, options) {
           node.type === "UnaryExpression" ||
           node.type === "UpdateExpression" ||
           node.type === "YieldExpression" ||
-          node.type === "TSNonNullExpression")
+          node.type === "TSNonNullExpression" ||
+          (node.type === "ClassExpression" && isNonEmptyArray(node.decorators)))
       ) {
         return true;
       }
@@ -766,10 +767,6 @@ function needsParens(path, options) {
       }
 
     case "ClassExpression":
-      if (isNonEmptyArray(node.decorators)) {
-        return true;
-      }
-
       switch (parent.type) {
         case "NewExpression":
           return key === "callee";

tests/format/js/decorators/__snapshots__/jsfmt.spec.js.snap

@@ -51,20 +51,16 @@ export class Bar {}
 export default class Baz {}
 
 const foo =
-  (
-    @deco
-    class {
-      //
-    }
-  );
+  @deco
+  class {
+    //
+  };
 
 const bar =
-  (
-    @deco
-    class {
-      //
-    }
-  );
+  @deco
+  class {
+    //
+  };
 
 ================================================================================
 `;
@@ -293,18 +289,14 @@ printWidth: 80
     @(decorators["first"])
     method() {}
   },
-  (
-    @(decorators[first])
-    class {
-      method() {}
-    }
-  ),
-  (
-    @(decorators[0])
-    class {
-      method() {}
-    }
-  ),
+  @(decorators[first])
+  class {
+    method() {}
+  },
+  @(decorators[0])
+  class {
+    method() {}
+  },
 ];
 
 ================================================================================

tests/format/js/decorators/class-expression/__snapshots__/jsfmt.spec.js.snap

@@ -76,16 +76,12 @@ console.log(@deco class {})
 
 =====================================output=====================================
 console.log(
-  (
-    @deco
-    class Foo {}
-  ),
+  @deco
+  class Foo {},
 )
 console.log(
-  (
-    @deco
-    class {}
-  ),
+  @deco
+  class {},
 )
 
 ================================================================================
@@ -102,16 +98,12 @@ console.log(@deco class {})
 
 =====================================output=====================================
 console.log(
-  (
-    @deco
-    class Foo {}
-  ),
+  @deco
+  class Foo {},
 );
 console.log(
-  (
-    @deco
-    class {}
-  ),
+  @deco
+  class {},
 );
 
 ================================================================================
@@ -213,15 +205,11 @@ const b2 = []
 
 =====================================output=====================================
 const a1 =
-  (
-    @deco
-    class Foo {}
-  )
+  @deco
+  class Foo {}
 const a2 =
-  (
-    @deco
-    class {}
-  )
+  @deco
+  class {}
 
 ;(
   @deco
@@ -274,15 +262,11 @@ const b2 = []
 
 =====================================output=====================================
 const a1 =
-  (
-    @deco
-    class Foo {}
-  );
+  @deco
+  class Foo {};
 const a2 =
-  (
-    @deco
-    class {}
-  );
+  @deco
+  class {};
 
 (
   @deco