Show actual edits when a file is renamed in Changes (#6559)

* fix(server): show actual edits when a file is renamed Path-limited patch requests discarded the detected rename source, so Git reported the destination as a new file. Include both literal paths and select the destination patch to preserve the rename and avoid duplicating changed copy sources. * fix(server): preserve small copy patches beside oversized sources Filter rename and copy output before enforcing the bounded request budget, so a modified source cannot hide its small copy patch. --------- Co-authored-by: paseo-bot[bot] <266920839+paseo-bot[bot]@users.noreply.github.com>
2026-11-03 15:12:48 +00:00 · 2026-10-11 07:55:09 +02:00
parent cfb18f16d4
commit dd0350bc2b
2 changed files with 150 additions and 8 deletions
@@ -539,10 +539,129 @@ describe("checkout git utilities", () => {
    });

    expect(diff.structured).toContainEqual(
-      expect.objectContaining({ path: "renamed.txt", oldPath: "file.txt" }),
+      expect.objectContaining({
+        path: "renamed.txt",
+        oldPath: "file.txt",
+        additions: 0,
+        deletions: 0,
+        hunks: [],
+      }),
    );
  });

+  it.each([
+    { mode: "uncommitted", oldPath: "to-rename.txt", path: "renamed.txt" },
+    { mode: "base", oldPath: "to-rename.txt", path: "renamed.txt" },
+    { mode: "uncommitted", oldPath: "old [file].txt", path: "new [file].txt" },
+  ] as const)(
+    "shows only the edited line of a rename ($mode, $path)",
+    async ({ mode, oldPath, path }) => {
+      const original = Array.from({ length: 12 }, (_, index) => `line ${index + 1}`);
+      commitFile(repoDir, oldPath, original.join("\n") + "\n", "file to rename");
+      if (mode === "base") {
+        execFileSync("git", ["checkout", "-b", "feature/rename"], { cwd: repoDir });
+      }
+      execFileSync("git", ["mv", oldPath, path], { cwd: repoDir });
+      const edited = [...original];
+      edited[5] = "edited line 6";
+      writeFileSync(join(repoDir, path), edited.join("\n") + "\n");
+      execFileSync("git", ["add", path], { cwd: repoDir });
+
+      expect(
+        execFileSync("git", ["diff", "--name-status", "HEAD"], { cwd: repoDir }).toString(),
+      ).toMatch(/R\d+\t/);
+      if (mode === "base") {
+        execFileSync("git", ["-c", "commit.gpgsign=false", "commit", "-m", "rename and edit"], {
+          cwd: repoDir,
+        });
+      }
+
+      const diff = await getCheckoutDiff(repoDir, {
+        mode,
+        ...(mode === "base" ? { baseRef: "main" } : {}),
+        includeStructured: true,
+      });
+
+      expect(diff.structured).toEqual([
+        expect.objectContaining({
+          path,
+          oldPath,
+          isNew: false,
+          isDeleted: false,
+          additions: 1,
+          deletions: 1,
+          status: "ok",
+        }),
+      ]);
+      expect(diff.diff).toContain(`rename from ${oldPath}`);
+      expect(diff.diff).toContain(`rename to ${path}`);
+      expect(diff.diff).toContain("-line 6\n+edited line 6");
+      expect(diff.diff).not.toContain("new file mode");
+    },
+  );
+
+  it("includes a changed copy source only once in the diff", async () => {
+    const original =
+      Array.from({ length: 12 }, (_, index) => `line ${index + 1}`).join("\n") + "\n";
+    commitFile(repoDir, "source.txt", original, "copy source");
+    execFileSync("git", ["config", "diff.renames", "copies"], { cwd: repoDir });
+    writeFileSync(join(repoDir, "copy.txt"), original);
+    writeFileSync(join(repoDir, "source.txt"), original.replace("line 6", "edited line 6"));
+    execFileSync("git", ["add", "copy.txt", "source.txt"], { cwd: repoDir });
+    expect(
+      execFileSync("git", ["diff", "--name-status", "HEAD"], { cwd: repoDir }).toString(),
+    ).toContain("C100\tsource.txt\tcopy.txt");
+
+    const diff = await getCheckoutDiff(repoDir, {
+      mode: "uncommitted",
+      includeStructured: true,
+    });
+    expect(diff.structured).toEqual([
+      expect.objectContaining({
+        path: "copy.txt",
+        oldPath: "source.txt",
+        additions: 0,
+        deletions: 0,
+      }),
+      expect.objectContaining({ path: "source.txt", additions: 1, deletions: 1 }),
+    ]);
+    expect(diff.diff.match(/^diff --git a\/source.txt b\/source.txt$/gm)).toHaveLength(1);
+    expect(diff.diff).toContain("copy from source.txt");
+    expect(diff.diff).toContain("copy to copy.txt");
+  });
+
+  it("keeps a small copy patch when its edited source exceeds the patch limit", async () => {
+    const original =
+      Array.from({ length: 12 }, (_, index) => `line ${index + 1}`).join("\n") + "\n";
+    commitFile(repoDir, "source.txt", original, "copy source");
+    execFileSync("git", ["config", "diff.renames", "copies"], { cwd: repoDir });
+    writeFileSync(join(repoDir, "copy.txt"), original);
+    writeFileSync(join(repoDir, "source.txt"), original + "added source line\n".repeat(80_000));
+    execFileSync("git", ["add", "copy.txt", "source.txt"], { cwd: repoDir });
+    expect(
+      execFileSync("git", ["diff", "--name-status", "HEAD"], { cwd: repoDir }).toString(),
+    ).toContain("C100\tsource.txt\tcopy.txt");
+
+    const diff = await getCheckoutDiff(repoDir, {
+      mode: "uncommitted",
+      includeStructured: true,
+    });
+    expect(diff.structured).toEqual([
+      expect.objectContaining({
+        path: "copy.txt",
+        oldPath: "source.txt",
+        additions: 0,
+        deletions: 0,
+        hunks: [],
+        status: "ok",
+      }),
+      expect.objectContaining({ path: "source.txt", status: "too_large", hunks: [] }),
+    ]);
+    expect(diff.diff).toContain("copy from source.txt");
+    expect(diff.diff).toContain("copy to copy.txt");
+    expect(diff.diff).not.toContain("+added source line");
+  });
+
  it("reads the origin URL once when collecting facts for an origin-tracking branch", async () => {
    setupRemoteTrackingMain(repoDir, tempDir);