Function TestSpec_PublicAPI_ReadFileFromHEAD

pkg/gitutil/spec_test.go:368–399

TestSpec_PublicAPI_ReadFileFromHEAD validates the documented behavior of ReadFileFromHEAD as described in the package README.md. Specification: Reads a file's content from the HEAD commit without touching the working tree; rejects paths that escape the repository.

(t *testing.T)

// Specification: Reads a file's content from the HEAD commit without touching
// the working tree; rejects paths that escape the repository.
func TestSpec_PublicAPI_ReadFileFromHEAD(t *testing.T) {
	root, err := gitutil.FindGitRoot()
	if err != nil {
		t.Skip("not inside a git repository, skipping ReadFileFromHEAD tests")
	}

	t.Run("reads known file from HEAD without error", func(t *testing.T) {
		content, err := gitutil.ReadFileFromHEAD(filepath.Join(root, "go.mod"), root)
		require.NoError(t, err, "ReadFileFromHEAD should read go.mod without error")
		assert.NotEmpty(t, content, "content of go.mod should not be empty")
	})

	t.Run("returns error for non-existent file", func(t *testing.T) {
		_, err := gitutil.ReadFileFromHEAD("this-file-does-not-exist-xyzzy.txt", root)
		assert.Error(t, err, "ReadFileFromHEAD should return error for non-existent file")
	})

	t.Run("rejects path with .. traversal", func(t *testing.T) {
		// Specification: "The function rejects paths that escape the repository
		// (i.e. paths containing .. after resolution)."
		outsidePath := filepath.Join(root, "..", "outside.txt")
		_, err := gitutil.ReadFileFromHEAD(outsidePath, root)
		require.Error(t, err, "ReadFileFromHEAD should reject path-traversal attempts")
		assert.Contains(t, err.Error(), "outside the git repository root")
	})

	t.Run("returns error when gitRoot is empty", func(t *testing.T) {
		// Specification: gitRoot must be the repository root (from FindGitRoot)
		_, err := gitutil.ReadFileFromHEAD("go.mod", "")
		assert.Error(t, err, "ReadFileFromHEAD should return error when gitRoot is empty")
	})
}