Fix printing of single-param async arrow function with comments (#13136)

* Fix printing of async arrow function with a single param and comments

* Add OVERWRITE support to generator tests

packages/babel-generator/src/generators/methods.ts

@@ -119,9 +119,11 @@ export function ArrowFunctionExpression(
   ) {
     if (
       (this.format.retainLines || node.async) &&
-      node.loc &&
+      ((node.loc &&
         node.body.loc &&
-      node.loc.start.line < node.body.loc.start.line
+        node.loc.start.line < node.body.loc.start.line) ||
+        firstParam.leadingComments?.length ||
+        firstParam.trailingComments?.length)
     ) {
       this.token("(");
       if (firstParam.loc && firstParam.loc.start.line > node.loc.start.line) {

packages/babel-generator/test/fixtures/comments/async-arrow-single-param-with-comments/input.js

@@ -0,0 +1,5 @@
+async (/** @type {any} */ arg) => {};
+
+async (arg /* trailing */) => {};
+
+async (/** @type {any} */ arg /* trailing */) => {};

packages/babel-generator/test/fixtures/comments/async-arrow-single-param-with-comments/output.js

@@ -0,0 +1,13 @@
+async (
+/** @type {any} */
+arg) => {};
+
+async (arg
+/* trailing */
+) => {};
+
+async (
+/** @type {any} */
+arg
+/* trailing */
+) => {};

packages/babel-generator/test/index.js

@@ -819,7 +819,13 @@ suites.forEach(function (testSuite) {
                 console.log(`New test file created: ${expected.loc}`);
                 fs.writeFileSync(expected.loc, result.code);
               } else {
+                try {
                   expect(result.code).toBe(expected.code);
+                } catch (e) {
+                  if (!process.env.OVERWRITE) throw e;
+                  console.log(`Updated test file: ${expected.loc}`);
+                  fs.writeFileSync(expected.loc, result.code);
+                }
               }
             }
           }