Repository: jlongster/prettier (js)

Issue:
Invalid comment with empty array and last argument expansion
```js
expect(() => {}).toTriggerReadyStateChanges([
  // Nothing.
]);
```

turns into

```js
expect(() => {}).toTriggerReadyStateChanges(
  [
    // Nothing.],
);
```

which doesn't parse

https://jlongster.github.io/prettier/#%7B%22content%22%3A%22expect(()%20%3D%3E%20%7B%7D).toTriggerReadyStateChanges(%5B%5Cn%20%20%2F%2F%20Nothing.%5Cn%5D)%3B%5Cn%22%2C%22options%22%3A%7B%22printWidth%22%3A80%2C%22tabWidth%22%3A2%2C%22singleQuote%22%3Atrue%2C%22trailingComma%22%3Atrue%2C%22bracketSpacing%22%3Atrue%2C%22doc%22%3Afalse%7D%7D

Pull request description:
Fix dangling comments for arrays
It was missing a softline. I copy and pasted the dangling handling for objects.

Fixes #624

Patch:
diff --git a/editors/jetbrains/README.md b/editors/jetbrains/README.md
index f75eddde7..1a7ae61f4 100644
--- a/editors/jetbrains/README.md
+++ b/editors/jetbrains/README.md
@@ -14,6 +14,6 @@ If on the other hand you have `prettier` installed locally, replace the **Progra
 
 ### Configure Keymap
 
-Now when you setup **External Tool** I guess you what to add hotkey for it. Go to *File | Settings | Keymap* for Windows and Linux *WebStorm | Preferences | Keymap* and type external tool name in search box.
+Now when you setup **External Tool** I guess you want to add hotkey for it. Go to *File | Settings | Keymap* for Windows and Linux *WebStorm | Preferences | Keymap* and type external tool name in search box.
 
 See [this documentation](https://www.jetbrains.com/help/webstorm/configuring-keyboard-shortcuts.html) about configuring keyboard shortcuts.
diff --git a/src/printer.js b/src/printer.js
index e78ec9718..9a46ef7e0 100644
--- a/src/printer.js
+++ b/src/printer.js
@@ -712,7 +712,14 @@ function genericPrintNoParens(path, options, print) {
     case "ArrayPattern":
       if (n.elements.length === 0) {
         parts.push(
-          concat(["[", comments.printDanglingComments(path, options), "]"])
+          group(
+            concat([
+              "[",
+              comments.printDanglingComments(path, options),
+              softline,
+              "]"
+            ])
+          )
         );
       } else {
         const lastElem = util.getLast(n.elements);


Test patch:
diff --git a/tests/comments/__snapshots__/jsfmt.spec.js.snap b/tests/comments/__snapshots__/jsfmt.spec.js.snap
index 063b75f2d..b6c036234 100644
--- a/tests/comments/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/comments/__snapshots__/jsfmt.spec.js.snap
@@ -74,6 +74,32 @@ declare class Foo extends Qux<string> {/* dangling */}
 "
 `;
 
+exports[`test dangling_array.js 1`] = `
+"expect(() => {}).toTriggerReadyStateChanges([
+  // Nothing.
+]);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+expect(() => {}).toTriggerReadyStateChanges(
+  [
+    // Nothing.
+  ]
+);
+"
+`;
+
+exports[`test dangling_array.js 2`] = `
+"expect(() => {}).toTriggerReadyStateChanges([
+  // Nothing.
+]);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+expect(() => {}).toTriggerReadyStateChanges(
+  [
+    // Nothing.
+  ]
+);
+"
+`;
+
 exports[`test first-line.js 1`] = `
 "a // comment
 b
diff --git a/tests/comments/dangling_array.js b/tests/comments/dangling_array.js
new file mode 100644
index 000000000..599897d57
--- /dev/null
+++ b/tests/comments/dangling_array.js
@@ -0,0 +1,3 @@
+expect(() => {}).toTriggerReadyStateChanges([
+  // Nothing.
+]);