atlas-iac/testing/tests/test_quality_coverage_helpers.py

"""Focused coverage-helper tests for titan-iac quality modules."""

from __future__ import annotations

import textwrap
from pathlib import Path

from testing.quality_coverage import compute_workspace_line_coverage, run_check


def test_compute_workspace_line_coverage_handles_missing_xml(tmp_path: Path) -> None:
    """Missing coverage XML should produce a zero workspace coverage score."""

    contract = {"coverage": {"tracked_files": ["managed.py"]}}
    assert (
        compute_workspace_line_coverage(contract, tmp_path, tmp_path / "missing.xml")
        == 0.0
    )


def test_compute_workspace_line_coverage_averages_present_tracked_files(
    tmp_path: Path,
) -> None:
    """Workspace coverage should average only tracked files that appear in the report."""

    coverage_xml = tmp_path / "coverage.xml"
    coverage_xml.write_text(
        textwrap.dedent(
            """\
            <coverage>
              <packages>
                <package>
                  <classes>
                    <class filename="alpha.py" line-rate="1.0" />
                    <class filename="beta.py" line-rate="0.5" />
                  </classes>
                </package>
              </packages>
            </coverage>
            """
        ),
        encoding="utf-8",
    )

    contract = {"coverage": {"tracked_files": ["alpha.py", "beta.py", "missing.py"]}}
    assert compute_workspace_line_coverage(contract, tmp_path, coverage_xml) == 75.0


def test_run_check_keeps_relative_names_when_source_roots_do_not_match(
    tmp_path: Path,
) -> None:
    """Relative filenames should remain relative when no declared source root contains them."""

    coverage_xml = tmp_path / "coverage.xml"
    unmatched_root = tmp_path / "other-root"
    unmatched_root.mkdir()
    coverage_xml.write_text(
        textwrap.dedent(
            f"""\
            <coverage>
              <sources>
                <source>{unmatched_root}</source>
              </sources>
              <packages>
                <package>
                  <classes>
                    <class filename="relative.py" line-rate="0.80" branch-rate="1.0" />
                  </classes>
                </package>
              </packages>
            </coverage>
            """
        ),
        encoding="utf-8",
    )

    issues = run_check(
        {"coverage": {"minimum_percent": 95.0, "tracked_files": ["relative.py"]}},
        tmp_path,
        coverage_xml,
    )

    assert issues == ["line coverage below 95.0%: relative.py (80.0%)"]


def test_workspace_coverage_returns_zero_when_xml_has_no_tracked_samples(
    tmp_path: Path,
) -> None:
    xml = tmp_path / "coverage.xml"
    xml.write_text("<coverage><packages /></coverage>", encoding="utf-8")
    assert (
        compute_workspace_line_coverage(
            {"coverage": {"tracked_files": ["missing.py"]}}, tmp_path, xml
        )
        == 0.0
    )


def test_run_check_fails_a_file_below_the_branch_floor(tmp_path: Path) -> None:
    """Full line coverage must never hide a file whose branch coverage is weak."""

    coverage_xml = tmp_path / "coverage.xml"
    coverage_xml.write_text(
        textwrap.dedent(
            """\
            <coverage>
              <packages>
                <package>
                  <classes>
                    <class filename="weak.py" line-rate="1.0" branch-rate="0.90" />
                    <class filename="solid.py" line-rate="1.0" branch-rate="0.95" />
                  </classes>
                </package>
              </packages>
            </coverage>
            """
        ),
        encoding="utf-8",
    )

    issues = run_check(
        {"coverage": {"minimum_percent": 95.0, "tracked_files": ["weak.py", "solid.py"]}},
        tmp_path,
        coverage_xml,
    )

    assert issues == ["branch coverage below 95.0%: weak.py (90.0%)"]


def test_run_check_fails_closed_when_branch_evidence_is_absent(tmp_path: Path) -> None:
    """A report generated without branch measurement cannot satisfy the gate."""

    coverage_xml = tmp_path / "coverage.xml"
    coverage_xml.write_text(
        textwrap.dedent(
            """\
            <coverage>
              <packages>
                <package>
                  <classes>
                    <class filename="unmeasured.py" line-rate="1.0" />
                  </classes>
                </package>
              </packages>
            </coverage>
            """
        ),
        encoding="utf-8",
    )

    issues = run_check(
        {"coverage": {"minimum_percent": 95.0, "tracked_files": ["unmeasured.py"]}},
        tmp_path,
        coverage_xml,
    )

    assert issues == ["branch coverage missing for tracked file: unmeasured.py"]