Refactor git integration tests as unit tests

tests/git.test.ts

@@ -29,22 +29,38 @@ async function setupGit(cwd: string) {
 describe("getFileChanges", () => {
   it("should get changes since a specific ref", async () => {
     await using fixture = await createFixture({
-      "foo.txt": "Hello, world!",
+      ".gitignore": ".env\nignored",
+      "a.txt": "Hello, world!",
+      "b.txt": "Hello, world!",
     });
     await setupGit(fixture.path);
 
-    await fixture.rm("foo.txt");
-    await fixture.writeFile("bar.txt", "This is a new file!");
+    await fixture.writeFile("a.txt", "This is an updated file!");
+    await fixture.rm("b.txt");
+    await fixture.writeFile("c.txt", "This is a new file!");
+    await fixture.mkdir("nested");
+    await fixture.writeFile("nested/file.txt", "This is a nested file");
+    await fixture.mkdir("ignored");
+    await fixture.writeFile("ignored/file.txt", "This file should be ignored");
+    await fixture.writeFile(".env", "This file should be ignored");
 
     const result = await getFileChanges(fixture.path, fixture.path, "HEAD");
     expect(result).toEqual({
       additions: [
         {
-          path: "bar.txt",
-          contents: await fixture.readFile("bar.txt", "base64"),
+          path: "a.txt",
+          contents: await fixture.readFile("a.txt", "base64"),
+        },
+        {
+          path: "c.txt",
+          contents: await fixture.readFile("c.txt", "base64"),
+        },
+        {
+          path: "nested/file.txt",
+          contents: await fixture.readFile("nested/file.txt", "base64"),
         },
       ],
-      deletions: [{ path: "foo.txt" }],
+      deletions: [{ path: "b.txt" }],
     });
   });
 
@@ -105,4 +121,111 @@ describe("getFileChanges", () => {
       deletions: [{ path: "nested/foo.txt" }],
     });
   });
+
+  it("should allow existing symlinks", async () => {
+    await using fixture = await createFixture({
+      "foo.txt": "Hello, world!",
+      "bar.txt": "Hello, world!",
+    });
+    await setupGit(fixture.path);
+
+    await fixture.mkdir("some-dir");
+    await fs.symlink(
+      fixture.getPath("foo.txt"),
+      fixture.getPath("some-dir/nested"),
+    );
+    await exec("git", ["add", "."], { nodeOptions: { cwd: fixture.path } });
+    await exec("git", ["commit", "-m", "Add symlink"], {
+      nodeOptions: { cwd: fixture.path },
+    });
+
+    // Since we committed, HEAD points to the last commit and there's no change since then
+    const result = await getFileChanges(fixture.path, fixture.path, "HEAD");
+    expect(result).toEqual({ additions: [], deletions: [] });
+
+    await fixture.rm("some-dir/nested");
+    await fs.symlink(
+      fixture.getPath("bar.txt"),
+      fixture.getPath("some-dir/nested"),
+    );
+
+    // We made symlink changes since the last commit, so this should error now
+    await expect(
+      getFileChanges(fixture.path, fixture.path, "HEAD"),
+    ).rejects.toThrow(
+      "Unexpected symlink at some-dir/nested, GitHub API only supports files and directories. You may need to add this file to .gitignore",
+    );
+  });
+
+  it("should not error when symlink is present but ignored", async () => {
+    await using fixture = await createFixture({
+      "foo.txt": "Hello, world!",
+    });
+    await setupGit(fixture.path);
+
+    await fixture.writeFile(".gitignore", "some-dir");
+    await exec("git", ["add", "."], { nodeOptions: { cwd: fixture.path } });
+    await exec("git", ["commit", "-m", "Add gitignore"], {
+      nodeOptions: { cwd: fixture.path },
+    });
+
+    await fixture.mkdir("some-dir");
+    await fs.symlink(
+      fixture.getPath("foo.txt"),
+      fixture.getPath("some-dir/nested"),
+    );
+
+    const result = await getFileChanges(fixture.path, fixture.path, "HEAD");
+    expect(result).toEqual({ additions: [], deletions: [] });
+  });
+
+  it("should throw error when symlink is present with non-existent path", async () => {
+    await using fixture = await createFixture();
+    await setupGit(fixture.path);
+
+    await fixture.mkdir("some-dir");
+    await fs.symlink(
+      fixture.getPath("non-existent"),
+      fixture.getPath("some-dir/nested"),
+    );
+
+    await expect(
+      getFileChanges(fixture.path, fixture.path, "HEAD"),
+    ).rejects.toThrow(
+      "Unexpected symlink at some-dir/nested, GitHub API only supports files and directories. You may need to add this file to .gitignore",
+    );
+  });
+
+  it("should throw error when symlink is present with existing path", async () => {
+    await using fixture = await createFixture({
+      "foo.txt": "Hello, world!",
+    });
+    await setupGit(fixture.path);
+
+    await fixture.mkdir("some-dir");
+    await fs.symlink(
+      fixture.getPath("foo.txt"),
+      fixture.getPath("some-dir/nested"),
+    );
+
+    await expect(
+      getFileChanges(fixture.path, fixture.path, "HEAD"),
+    ).rejects.toThrow(
+      "Unexpected symlink at some-dir/nested, GitHub API only supports files and directories. You may need to add this file to .gitignore",
+    );
+  });
+
+  it("should throw error when executable file is present", async () => {
+    await using fixture = await createFixture();
+    await setupGit(fixture.path);
+
+    await fixture.writeFile("executable-file.sh", "#!/bin/bash\necho hello");
+    await fs.chmod(fixture.getPath("executable-file.sh"), 0o755);
+
+    await expect(
+      getFileChanges(fixture.path, fixture.path, "HEAD"),
+    ).rejects.toThrow(
+      "Unexpected executable file at executable-file.sh, GitHub API only supports non-executable files and directories. You may need to add this file to .gitignore",
+    );
+  });
 });