From d8534021cc605a4f83d1320cd97066ad65aebe9c Mon Sep 17 00:00:00 2001
From: Shrey Sudhir <shrey.somaiya@gmail.com>
Date: Sat, 20 Jan 2024 18:32:01 +1100
Subject: [PATCH] fix(formatter): correctly handle comments at end of
 export/import list (#1603)

---
 CHANGELOG.md                                  |  2 +
 crates/biome_js_formatter/src/comments.rs     | 21 ++++++
 .../js/module/comments/import_exports.js      | 15 +++++
 .../js/module/comments/import_exports.js.snap | 66 +++++++++++++++++++
 .../src/content/docs/internals/changelog.mdx  |  2 +
 5 files changed, 106 insertions(+)
 create mode 100644 crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js
 create mode 100644 crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js.snap

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8bd4157bd8ae..2559b62a3f04 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,8 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 
 - Fix [#1584](https://github.com/biomejs/biome/issues/1584). Ensure the LSP only registers the formatter once. Contributed by @nhedger
 
+- Fix [#1589](https://github.com/biomejs/biome/issues/1589). Fix invalid formatting of own line comments when they were at the end of an import/export list. Contributed by @spanishpear
+
 ### Configuration
 
 ### Editors
diff --git a/crates/biome_js_formatter/src/comments.rs b/crates/biome_js_formatter/src/comments.rs
index 4b938e6079c1..3016bc9d1038 100644
--- a/crates/biome_js_formatter/src/comments.rs
+++ b/crates/biome_js_formatter/src/comments.rs
@@ -1253,6 +1253,27 @@ fn handle_import_export_specifier_comment(
             }
         }
 
+        JsSyntaxKind::JS_EXPORT_NAMED_FROM_CLAUSE => {
+            if let Some(following_token) = comment.following_token() {
+                // if we are at the end of a list of import specifiers
+                // and encounter a comment
+                // ```javascript
+                // import {
+                //   MULTI,
+                //   LINE,
+                //   THING,
+                //   // some comment here
+                // } from 'foo'
+                // - then attach it as a trailing comment to `THING`
+                if matches!(following_token.kind(), JsSyntaxKind::R_CURLY) {
+                    if let Some(preceding) = comment.preceding_node() {
+                        return CommentPlacement::trailing(preceding.clone(), comment);
+                    }
+                }
+            }
+            CommentPlacement::Default(comment)
+        }
+
         _ => CommentPlacement::Default(comment),
     }
 }
diff --git a/crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js b/crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js
new file mode 100644
index 000000000000..b5636eb99cba
--- /dev/null
+++ b/crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js
@@ -0,0 +1,15 @@
+export {
+    THING, 
+    HERE,
+    MULTI,
+    LINE
+    // comment here should not get moved
+} from 'foo';
+
+import {
+    THING, 
+    HERE,
+    MULTI,
+    LINE
+    // comment here should not get moved
+} from 'foo';
\ No newline at end of file
diff --git a/crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js.snap b/crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js.snap
new file mode 100644
index 000000000000..a8ad46c4be0e
--- /dev/null
+++ b/crates/biome_js_formatter/tests/specs/js/module/comments/import_exports.js.snap
@@ -0,0 +1,66 @@
+---
+source: crates/biome_formatter_test/src/snapshot_builder.rs
+info: js/module/comments/import_exports.js
+---
+
+# Input
+
+```js
+export {
+    THING, 
+    HERE,
+    MULTI,
+    LINE
+    // comment here should not get moved
+} from 'foo';
+
+import {
+    THING, 
+    HERE,
+    MULTI,
+    LINE
+    // comment here should not get moved
+} from 'foo';
+```
+
+
+=============================
+
+# Outputs
+
+## Output 1
+
+-----
+Indent style: Tab
+Indent width: 2
+Line ending: LF
+Line width: 80
+Quote style: Double Quotes
+JSX quote style: Double Quotes
+Quote properties: As needed
+Trailing comma: All
+Semicolons: Always
+Arrow parentheses: Always
+Bracket spacing: true
+Bracket same line: false
+-----
+
+```js
+export {
+	THING,
+	HERE,
+	MULTI,
+	LINE,
+	// comment here should not get moved
+} from "foo";
+
+import {
+	THING,
+	HERE,
+	MULTI,
+	LINE,
+	// comment here should not get moved
+} from "foo";
+```
+
+
diff --git a/website/src/content/docs/internals/changelog.mdx b/website/src/content/docs/internals/changelog.mdx
index e8dc33296ce7..d7e2c0a259e3 100644
--- a/website/src/content/docs/internals/changelog.mdx
+++ b/website/src/content/docs/internals/changelog.mdx
@@ -26,6 +26,8 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 
 - Fix [#1584](https://github.com/biomejs/biome/issues/1584). Ensure the LSP only registers the formatter once. Contributed by @nhedger
 
+- Fix [#1589](https://github.com/biomejs/biome/issues/1589). Fix invalid formatting of own line comments when they were at the end of an import/export list. Contributed by @spanishpear
+
 ### Configuration
 
 ### Editors