devx/tests/unit/test_check_pr_size.py

"""Unit tests for devx.ci.check_pr_size."""

from unittest.mock import MagicMock, patch

from click.testing import CliRunner

from devx.ci.check_pr_size import (
    check_size,
    cli,
    get_diff_stats,
    is_excluded,
)


class TestIsExcluded:
    def test_excludes_changelog(self) -> None:
        assert is_excluded("CHANGELOG.md", ["CHANGELOG.md"])

    def test_excludes_svg_glob(self) -> None:
        assert is_excluded("docs/badges/coverage.svg", ["*.svg"])

    def test_does_not_exclude_source(self) -> None:
        assert not is_excluded("src/devx/ci/check_pr_size.py", ["CHANGELOG.md", "*.svg"])

    def test_excludes_readme(self) -> None:
        assert is_excluded("README.md", ["README.md"])


class TestCheckSize:
    def test_under_limits_passes(self) -> None:
        stats = [("src/main.py", 100, 50), ("tests/test_main.py", 80, 20)]
        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=[])
        assert ok is True
        assert "250" in detail  # 100+50+80+20

    def test_over_lines_fails(self) -> None:
        stats = [("src/main.py", 300, 300)]
        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=[])
        assert ok is False
        assert "600" in detail

    def test_over_files_fails(self) -> None:
        stats = [(f"src/file{i}.py", 10, 5) for i in range(15)]
        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=[])
        assert ok is False
        assert "15" in detail

    def test_excluded_files_not_counted(self) -> None:
        stats = [("CHANGELOG.md", 500, 500), ("src/main.py", 10, 5)]
        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=["CHANGELOG.md"])
        assert ok is True
        assert "15" in detail  # only 10+5

    def test_empty_stats_passes(self) -> None:
        ok, detail = check_size([], max_lines=500, max_files=10, excluded_patterns=[])
        assert ok is True


class TestGetDiffStats:
    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_parses_numstat_output(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            returncode=0,
            stdout="10\t5\tsrc/main.py\n20\t10\ttests/test_main.py\n",
            stderr="",
        )
        stats = get_diff_stats("origin/master", "HEAD")
        assert len(stats) == 2
        assert stats[0] == ("src/main.py", 10, 5)
        assert stats[1] == ("tests/test_main.py", 20, 10)

    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_handles_binary_files(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            returncode=0,
            stdout="-\t-\timage.png\n",
            stderr="",
        )
        stats = get_diff_stats("origin/master", "HEAD")
        assert len(stats) == 1
        assert stats[0] == ("image.png", 0, 0)

    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_empty_output(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(returncode=0, stdout="", stderr="")
        stats = get_diff_stats("origin/master", "HEAD")
        assert stats == []

    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_git_diff_failure_raises(self, mock_run: MagicMock) -> None:
        import pytest

        mock_run.return_value = MagicMock(returncode=1, stdout="", stderr="fatal: bad ref")
        with pytest.raises(Exception, match="git diff|bad ref"):
            get_diff_stats("origin/master", "HEAD")

    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_malformed_line_skipped(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            returncode=0,
            stdout="not_a_valid_line\n10\t5\tsrc/main.py\n",
            stderr="",
        )
        stats = get_diff_stats("origin/master", "HEAD")
        assert len(stats) == 1
        assert stats[0] == ("src/main.py", 10, 5)


class TestCli:
    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_passes_when_small(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            returncode=0,
            stdout="10\t5\tsrc/main.py\n",
            stderr="",
        )
        runner = CliRunner()
        result = runner.invoke(cli, ["--base", "origin/master", "--head", "HEAD"])
        assert result.exit_code == 0
        assert "OK" in result.output

    @patch("devx.ci.check_pr_size.subprocess.run")
    def test_fails_when_too_large(self, mock_run: MagicMock) -> None:
        mock_run.return_value = MagicMock(
            returncode=0,
            stdout="300\t300\tsrc/main.py\n",
            stderr="",
        )
        runner = CliRunner()
        result = runner.invoke(cli, ["--base", "origin/master", "--head", "HEAD", "--max-lines", "500"])
        assert result.exit_code != 0
        assert "600" in result.output