fix: print attributes on anonymous classes one per line

Attributes on `new` anonymous classes were collapsed onto a single line
(`new #[Lazy] #[Computed] #[Title("Staff")] class ...`). Print each
attribute group on its own line, like named classes, with `new` on its
own line.

Fixes #2437

Author: Dextheking1

src/printer.mjs

@@ -2118,25 +2118,30 @@ function printNode(path, options, print) {
 
       const parts = [];
 
-      parts.push("new ");
-
       if (isAnonymousClassNode) {
+        const hasAttrs =
+          node.what.attrGroups && node.what.attrGroups.length > 0;
+        // Attributes on anonymous classes print one per line, like named
+        // classes, with `new` on its own line.
+        const breakAfterNew = hasAttrs ? hardline : " ";
         parts.push(
+          "new",
+          breakAfterNew,
           node.what.leadingComments &&
             node.what.leadingComments[0].kind === "commentblock"
-            ? [printComments(node.what.leadingComments, options), " "]
+            ? [printComments(node.what.leadingComments, options), breakAfterNew]
             : "",
-          ...path.call(
-            () => printAttrs(path, options, print, { inline: true }),
-            "what"
-          ),
+          ...(hasAttrs
+            ? path.call(() => printAttrs(path, options, print), "what")
+            : []),
           node.what.isReadonly ? "readonly class" : "class",
           node.arguments.length > 0
             ? [" ", printArgumentsList(path, options, print)]
             : "",
           group(print("what"))
         );
       } else {
+        parts.push("new ");
         const isExpression = ["call", "offsetlookup"].includes(node.what.kind);
         const printed = [
           isExpression ? "(" : "",

tests/attributes/__snapshots__/jsfmt.spec.mjs.snap

@@ -1,4 +1,4 @@
-// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+// Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`attributes.php 1`] = `
 ====================================options=====================================
@@ -112,6 +112,19 @@ class ParamCommentFunctionAnnotation {
 
 }
 
+// issue #2437: attributes on anonymous classes print one per line
+$anonymous = new
+    #[Lazy]
+    #[Computed]
+    #[Title('Staff')]
+    class extends Component {
+        public $editing = [];
+
+        public $branches;
+    };
+
+$singleAttributeAnonymous = new #[Single] class {};
+
 =====================================output=====================================
 <?php
 
@@ -171,7 +184,9 @@ function Y(
     ]
     string $_,
 ): string {
-    return new #[NON, Anon] class {};
+    return new
+    #[NON, Anon]
+    class {};
 }
 
 #[
@@ -248,5 +263,20 @@ class ParamCommentFunctionAnnotation
     }
 }
 
+// issue #2437: attributes on anonymous classes print one per line
+$anonymous = new
+#[Lazy]
+#[Computed]
+#[Title("Staff")]
+class extends Component {
+    public $editing = [];
+
+    public $branches;
+};
+
+$singleAttributeAnonymous = new
+#[Single]
+class {};
+
 ================================================================================
 `;

tests/attributes/attributes.php

@@ -103,3 +103,16 @@ function bar2(
     }
 
 }
+
+// issue #2437: attributes on anonymous classes print one per line
+$anonymous = new
+    #[Lazy]
+    #[Computed]
+    #[Title('Staff')]
+    class extends Component {
+        public $editing = [];
+
+        public $branches;
+    };
+
+$singleAttributeAnonymous = new #[Single] class {};