Fix formatting for AssignmentExpression with ClassExpression (#9741)

* Fix formatting for asignment with superClass

* Add tests

* Changelog

* For only AssignmentExpression

* Remove unnecesary ifBreak

changelog_unreleased/javascript/9741.md

@@ -0,0 +1,27 @@
+#### Fix formatting for AssignmentExpression with ClassExpression (#9741 by @sosukesuzuki)
+
+<!-- prettier-ignore -->
+```js
+// Input
+module.exports = class A extends B {
+  method() {
+    console.log("foo");
+  }
+};
+
+// Prettier stable
+module.exports = class A extends (
+  B
+) {
+  method() {
+    console.log("foo");
+  }
+};
+
+// Prettier master
+module.exports = class A extends B {
+  method() {
+    console.log("foo");
+  }
+};
+```

src/language-js/print/class.js

@@ -131,13 +131,13 @@ function printList(path, options, print, listName) {
 function printSuperClass(path, options, print) {
   const printed = path.call(print, "superClass");
   const parent = path.getParentNode();
-  if (parent && parent.type === "AssignmentExpression") {
-    return concat([
-      ifBreak("("),
-      indent(concat([softline, printed])),
-      softline,
-      ifBreak(")"),
-    ]);
+  if (parent.type === "AssignmentExpression") {
+    return group(
+      ifBreak(
+        concat(["(", indent(concat([softline, printed])), softline, ")"]),
+        printed
+      )
+    );
   }
   return printed;
 }

tests/js/classes/__snapshots__/jsfmt.spec.js.snap

@@ -32,6 +32,12 @@ foo = class extends aaaaaaaa.bbbbbbbb.cccccccc.dddddddd.eeeeeeee.ffffffff.gggggg
   }
 };
 
+module.exports = class A extends B {
+  method () {
+    console.log("foo");
+  }
+};
+
 =====================================output=====================================
 aaaaaaaa.bbbbbbbb.cccccccc.dddddddd.eeeeeeee.ffffffff.gggggggg2 = class extends (
   aaaaaaaa.bbbbbbbb.cccccccc.dddddddd.eeeeeeee.ffffffff.gggggggg1
@@ -41,9 +47,7 @@ aaaaaaaa.bbbbbbbb.cccccccc.dddddddd.eeeeeeee.ffffffff.gggggggg2 = class extends
   }
 };
 
-foo = class extends (
-  bar
-) {
+foo = class extends bar {
   method() {
     console.log("foo");
   }
@@ -65,6 +69,12 @@ foo = class extends (
   }
 };
 
+module.exports = class A extends B {
+  method() {
+    console.log("foo");
+  }
+};
+
 ================================================================================
 `;
 

tests/js/classes/assignment.js

@@ -23,3 +23,9 @@ foo = class extends aaaaaaaa.bbbbbbbb.cccccccc.dddddddd.eeeeeeee.ffffffff.gggggg
     console.log("foo");
   }
 };
+
+module.exports = class A extends B {
+  method () {
+    console.log("foo");
+  }
+};