From 7a76e5d08ed9a54c79a8687aed46b7ac44a73857 Mon Sep 17 00:00:00 2001
From: Evilebot Tnawi <evilebottnawi@users.noreply.github.com>
Date: Wed, 15 May 2019 18:46:12 +0300
Subject: [PATCH] fix(javascript): correctly handle comments in empty arrow
 function expressions (#6086)

---
 CHANGELOG.unreleased.md                        | 15 +++++++++++++++
 src/language-js/comments.js                    |  4 +---
 .../comments/__snapshots__/jsfmt.spec.js.snap  | 18 ++++++++++++++++++
 tests/comments/arrow.js                        |  3 +++
 4 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 tests/comments/arrow.js

diff --git a/CHANGELOG.unreleased.md b/CHANGELOG.unreleased.md
index bc4e886e..c54e4edf 100644
--- a/CHANGELOG.unreleased.md
+++ b/CHANGELOG.unreleased.md
@@ -95,6 +95,20 @@ console.log(
 );
 ```
 
+### JavaScript: Correctly handle comments in empty arrow function expressions ([#6086] by [@evilebottnawi])
+
+<!-- prettier-ignore -->
+```js
+// Input
+const fn = (/*event, data*/) => doSomething(anything);
+
+// Output (Prettier stable)
+const fn = () => /*event, data*/ doSomething(anything);
+
+// Output (Prettier master)
+const fn = (/*event, data*/) => doSomething(anything);
+```
+
 ### TypeScript: Keep trailing comma in tsx type parameters ([#6115] by [@sosukesuzuki])
 
 Previously, a trailing comma after single type parameter in arrow function was cleaned up. The formatted result is valid as ts, but is invalid as tsx. Prettier master fixes this issue.
@@ -203,6 +217,7 @@ This changes the method of finding the required count of backticks from using 2
 ````
 
 [#5979]: https://github.com/prettier/prettier/pull/5979
+[#6086]: https://github.com/prettier/prettier/pull/6086
 [#6088]: https://github.com/prettier/prettier/pull/6088
 [#6115]: https://github.com/prettier/prettier/pull/6115
 [#6106]: https://github.com/prettier/prettier/pull/6106
diff --git a/src/language-js/comments.js b/src/language-js/comments.js
index be1394e0..8048bb82 100644
--- a/src/language-js/comments.js
+++ b/src/language-js/comments.js
@@ -558,9 +558,7 @@ function handleCommentInEmptyParens(text, enclosingNode, comment, options) {
     enclosingNode &&
     (((enclosingNode.type === "FunctionDeclaration" ||
       enclosingNode.type === "FunctionExpression" ||
-      (enclosingNode.type === "ArrowFunctionExpression" &&
-        (enclosingNode.body.type !== "CallExpression" ||
-          enclosingNode.body.arguments.length === 0)) ||
+      enclosingNode.type === "ArrowFunctionExpression" ||
       enclosingNode.type === "ClassMethod" ||
       enclosingNode.type === "ObjectMethod") &&
       enclosingNode.params.length === 0) ||
diff --git a/tests/comments/__snapshots__/jsfmt.spec.js.snap b/tests/comments/__snapshots__/jsfmt.spec.js.snap
index 1cc4bce1..f40d5959 100644
--- a/tests/comments/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/comments/__snapshots__/jsfmt.spec.js.snap
@@ -1,5 +1,23 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`arrow.js 1`] = `
+====================================options=====================================
+parsers: ["flow", "babel"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+const fn = (/*event, data*/) => doSomething();
+
+const fn2 = (/*event, data*/) => doSomething(anything);
+
+=====================================output=====================================
+const fn = (/*event, data*/) => doSomething();
+
+const fn2 = (/*event, data*/) => doSomething(anything);
+
+================================================================================
+`;
+
 exports[`assignment-pattern.js 1`] = `
 ====================================options=====================================
 parsers: ["flow", "babel"]
diff --git a/tests/comments/arrow.js b/tests/comments/arrow.js
new file mode 100644
index 00000000..699f4d36
--- /dev/null
+++ b/tests/comments/arrow.js
@@ -0,0 +1,3 @@
+const fn = (/*event, data*/) => doSomething();
+
+const fn2 = (/*event, data*/) => doSomething(anything);