polish: allow comments when printing single-binding arrow

babel · Oct 3, 2022 · 93b3596 · 93b3596
1 parent 11b8b5f
commit 93b3596
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Showing 4 changed files with 17 additions and 35 deletions.
diff --git a/packages/babel-generator/src/generators/methods.ts b/packages/babel-generator/src/generators/methods.ts
@@ -170,26 +170,26 @@ export function ArrowFunctionExpression(
   this: Printer,
   node: t.ArrowFunctionExpression,
 ) {
+  const { _noLineTerminator } = this;
   if (node.async) {
+    this._noLineTerminator = true;
     this.word("async");
     this.space();
   }
 
-  const firstParam = node.params[0];
-
   // Try to avoid printing parens in simple cases, but only if we're pretty
   // sure that they aren't needed by type annotations or potential newlines.
+  let firstParam;
   if (
     !this.format.retainLines &&
-    // Auxiliary comments can introduce unexpected newlines
-    !this.format.auxiliaryCommentBefore &&
-    !this.format.auxiliaryCommentAfter &&
     node.params.length === 1 &&
-    isIdentifier(firstParam) &&
-    !hasTypesOrComments(node, firstParam)
+    isIdentifier((firstParam = node.params[0])) &&
+    !hasTypes(node, firstParam)
   ) {
     this.print(firstParam, node);
+    this._noLineTerminator = _noLineTerminator;
   } else {
+    this._noLineTerminator = _noLineTerminator;
     this._params(node);
   }
 
@@ -205,7 +205,7 @@ export function ArrowFunctionExpression(
   this.print(node.body, node);
 }
 
-function hasTypesOrComments(
+function hasTypes(
   node: t.ArrowFunctionExpression,
   param: t.Identifier,
 ): boolean {
@@ -214,8 +214,6 @@ function hasTypesOrComments(
     node.returnType ||
     node.predicate ||
     param.typeAnnotation ||
-    param.optional ||
-    param.leadingComments?.length ||
-    param.trailingComments?.length
+    param.optional
   );
 }
diff --git a/packages/babel-generator/test/arrow-functions.js b/packages/babel-generator/test/arrow-functions.js
@@ -29,9 +29,8 @@ describe("parameter parentheses", () => {
     expect(output).toMatchInlineSnapshot(`
       "() => {};
 
-      (
       /*BEFORE*/
-      a) => {};
+      a => {};
 
       (
       /*BEFORE*/
@@ -41,9 +40,7 @@ describe("parameter parentheses", () => {
 
       async () => {};
 
-      async (
-      /*BEFORE*/
-      a) => {};
+      async /*BEFORE*/a => {};
 
       async (
       /*BEFORE*/
@@ -59,9 +56,7 @@ describe("parameter parentheses", () => {
     expect(output).toMatchInlineSnapshot(`
       "() => {};
 
-      (a
-      /*AFTER*/
-      ) => {};
+      a /*AFTER*/=> {};
 
       (a
       /*AFTER*/
@@ -71,9 +66,7 @@ describe("parameter parentheses", () => {
 
       async () => {};
 
-      async (a
-      /*AFTER*/
-      ) => {};
+      async a /*AFTER*/=> {};
 
       async (a
       /*AFTER*/

diff --git a/...s/babel-generator/test/fixtures/comments/async-arrow-single-param-with-comments/output.js b/...s/babel-generator/test/fixtures/comments/async-arrow-single-param-with-comments/output.js
@@ -1,13 +1,5 @@
-async (
-/** @type {any} */
-arg) => {};
+async /** @type {any} */arg => {};
 
-async (arg
-/* trailing */
-) => {};
+async arg /* trailing */ => {};
 
-async (
-/** @type {any} */
-arg
-/* trailing */
-) => {};
+async /** @type {any} */arg /* trailing */ => {};
diff --git a/packages/babel-generator/test/fixtures/parentheses/async-arrow-function/output.js b/packages/babel-generator/test/fixtures/parentheses/async-arrow-function/output.js
@@ -1,5 +1,4 @@
-const x = async ( // some comment
-a) => {
+const x = async /* some comment*/a => {
   return foo(await a);
 };