From 9b71d754cc2d2961bb4b7b8984e87dccacf85d81 Mon Sep 17 00:00:00 2001
From: Christoph Pader <chris@margelo.com>
Date: Thu, 11 Dec 2025 12:13:40 +0000
Subject: [PATCH] fix: handle `\ No newline at end of file" markers correctly`
 lines in diffs

---
 scripts/utils/Git.ts  |  3 +++
 tests/unit/GitTest.ts | 28 ++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/scripts/utils/Git.ts b/scripts/utils/Git.ts
index f76f5f2bbbd2..b42217bab587 100644
--- a/scripts/utils/Git.ts
+++ b/scripts/utils/Git.ts
@@ -254,6 +254,9 @@ class Git {
                 } else if (firstChar === ' ') {
                     // Context line - skip it (we only care about added/removed lines)
                     continue;
+                } else if (firstChar === '\\') {
+                    // "No newline at end of file" marker - skip it (metadata, not content)
+                    continue;
                 } else {
                     throw new Error(`Unknown line type! First character of line is ${firstChar}`);
                 }
diff --git a/tests/unit/GitTest.ts b/tests/unit/GitTest.ts
index a6716f238675..42c02ef488bb 100644
--- a/tests/unit/GitTest.ts
+++ b/tests/unit/GitTest.ts
@@ -508,6 +508,34 @@ describe('Git', () => {
             expect(file.addedLines.size).toBe(1);
             expect(file.removedLines.size).toBe(0);
         });
+
+        it('handles "No newline at end of file" markers correctly', () => {
+            const mockDiffOutput = dedent(`
+                diff --git a/file.ts b/file.ts
+                index 1234567..abcdefg 100644
+                --- a/file.ts
+                +++ b/file.ts
+                @@ -1,1 +1,1 @@
+                -const old = 'value';
+                \\ No newline at end of file
+                +const new = 'value';
+            `);
+
+            mockExecSync.mockReturnValue(mockDiffOutput);
+
+            const result = Git.diff('main');
+            const file = result.files.at(0);
+            expect(file).toBeDefined();
+            if (!file) {
+                return;
+            }
+
+            expect(file.filePath).toBe('file.ts');
+            expect(file.hunks).toHaveLength(1);
+            expect(file.modifiedLines.size).toBe(1);
+            // The "No newline" marker should be ignored, not counted as a line
+            expect(file.hunks.at(0)?.lines.length).toBe(2); // One removed, one added
+        });
     });
 
     describe('fileDiffType', () => {