Add regression test for dev dependencies

tests/test_regression.py

@@ -2,17 +2,21 @@
 break the functionality of conda-lock.  This is a regression test suite."""
 
 import io
+import itertools
 import logging
 import shutil
+import sys
 import textwrap
 
 from pathlib import Path
 from textwrap import dedent
-from typing import List, Union
+from typing import List, Optional, Union
 
 import pytest
 
-from conda_lock.conda_lock import run_lock
+from click.testing import CliRunner
+
+from conda_lock.conda_lock import main, run_lock
 from conda_lock.invoke_conda import _stderr_to_log, is_micromamba
 from conda_lock.lookup import DEFAULT_MAPPING_URL
 from conda_lock.models.lock_spec import VersionedDependency
@@ -242,3 +246,211 @@ def test_stderr_to_log_gh770(
         assert (
             record.message == expected_message
         ), f"Expected message '{expected_message}' but got '{record.message}'"
+
+
+@pytest.fixture
+def categories_environment_files(tmp_path: Path) -> List[Path]:
+    """Create test environment files with dependencies in different categories.
+
+    We set up three environment files corresponding to  three categories:
+    - main containing tzcode
+    - dev containing pixi
+    - mm containing micromamba
+    """
+    # Main environment file (no category specified = main)
+    main_content = """
+        channels:
+          - conda-forge
+        dependencies:
+          - tzcode
+    """
+    main_file = tmp_path / "environment.yml"
+    main_file.write_text(textwrap.dedent(main_content))
+
+    # Dev environment file
+    dev_content = """
+        channels:
+          - conda-forge
+        category: dev
+        dependencies:
+          - pixi
+    """
+    dev_file = tmp_path / "environment-dev.yml"
+    dev_file.write_text(textwrap.dedent(dev_content))
+
+    # Custom extra environment file
+    mm_content = """
+        channels:
+          - conda-forge
+        category: mm
+        dependencies:
+          - micromamba
+    """
+    mm_file = tmp_path / "environment-mm.yml"
+    mm_file.write_text(textwrap.dedent(mm_content))
+
+    return [main_file, dev_file, mm_file]
+
+
+dev_deps_and_extras_cli_regression = list(
+    itertools.product(
+        [False, True],  # dev_deps_are_empty
+        [None, True, False],  # dev_deps
+        [False, True],  # filter_cats
+        [[], ["dev"], ["mm"], ["dev", "mm"]],  # extras
+    )
+)
+
+
+def make_dev_deps_and_extras_cli_regression_id(
+    dev_deps_are_empty: bool,
+    dev_deps: Optional[bool],
+    filter_cats: bool,
+    extras: List[str],
+) -> str:
+    dev = (
+        ""
+        if dev_deps is None
+        else "--dev-dependencies"
+        if dev_deps
+        else "--no-dev-dependencies"
+    )
+    filter = "--filter-categories" if filter_cats else ""
+    extra = "--category=" + ",".join(extras) if extras else ""
+    empty_dev_deps = "empty-dev-deps" if dev_deps_are_empty else ""
+    nonempty_args = [arg for arg in [dev, filter, extra, empty_dev_deps] if arg]
+    return "_".join(nonempty_args) or "no_args"
+
+
+@pytest.mark.parametrize(
+    "dev_deps_are_empty,dev_deps,filter_cats,extras",
+    dev_deps_and_extras_cli_regression,
+    ids=[
+        make_dev_deps_and_extras_cli_regression_id(dde, d, f, e)
+        for dde, d, f, e in dev_deps_and_extras_cli_regression
+    ],
+)
+def test_dev_deps_and_extras_cli_regression(
+    monkeypatch: "pytest.MonkeyPatch",
+    categories_environment_files: List[Path],
+    mamba_exe: Path,
+    capsys: "pytest.CaptureFixture[str]",
+    dev_deps_are_empty: bool,
+    dev_deps: Optional[bool],
+    filter_cats: bool,
+    extras: List[str],
+):
+    """Test conda-lock's handling of dev dependencies, category filtering, and extras.
+
+    This test verifies:
+    1. The {dev-dependencies} template variable in filenames correctly reflects the dev
+       dependencies setting:
+       - "true" when dev_deps is None (default) or True
+       - "false" when dev_deps is False
+
+    2. Package inclusion based on categories and CLI options:
+       - Main category (tzcode) is always included
+       - Dev category (pixi) is included when:
+         * dev_deps is None or True (default behavior), or
+         * "dev" is in extras
+       - Custom category (micromamba) is included only when "mm" is in extras
+
+    3. File generation:
+       - Exactly one output file is generated
+       - Output filename correctly uses the {dev-dependencies} template variable
+
+    Test Parameters:
+        dev_deps: Controls --dev-dependencies flag
+            None: Default behavior (same as True)
+            True: --dev-dependencies
+            False: --no-dev-dependencies
+
+        filter_cats: Controls --filter-categories flag
+            True: Enable category filtering
+            False: Default behavior
+
+        extras: Controls which extra categories to include via --category
+            []: No extras
+            ["dev"]: Include dev category
+            ["mm"]: Include custom category
+            ["dev", "mm"]: Include both categories
+
+    The test matrix covers all combinations of these parameters (24 test cases)
+    to ensure consistent behavior across different CLI option combinations.
+    """
+    # Create output directory
+    output_dir = categories_environment_files[0].parent / "output"
+    output_dir.mkdir()
+
+    # Create a filename template using the {dev-dependencies} variable
+    filename_template = "conda-lock-{dev-dependencies}.lock"
+
+    # Build the command arguments
+    args = [
+        "lock",
+        "--conda",
+        str(mamba_exe),
+        "--platform=linux-64",
+        "--kind=explicit",
+        f"--filename-template={filename_template}",
+    ]
+
+    # Add environment files
+    for env_file in categories_environment_files:
+        if dev_deps_are_empty and env_file.name == "environment-dev.yml":
+            continue
+        args.extend(["-f", str(env_file)])
+
+    # Add optional arguments based on the test case
+    if dev_deps is not None:
+        args.append("--dev-dependencies" if dev_deps else "--no-dev-dependencies")
+    if filter_cats:
+        args.append("--filter-categories")
+    for extra in extras:
+        args.extend(["--category", extra])
+
+    # Run the command from the output directory
+    monkeypatch.chdir(output_dir)
+    runner = CliRunner(mix_stderr=False)
+    with capsys.disabled():
+        result = runner.invoke(main, args, catch_exceptions=False)
+    print(result.stdout, file=sys.stdout)
+    print(result.stderr, file=sys.stderr)
+    assert result.exit_code == 0
+
+    # Verify exactly one output file was generated
+    output_files = list(output_dir.glob("*"))
+    assert (
+        len(output_files) == 1
+    ), f"Expected exactly one output file, found {len(output_files)}"
+    output_file = output_files[0]
+
+    # Verify the filename matches the expected dev-dependencies value
+    expected_dev_str = "true" if dev_deps in (None, True) else "false"
+    expected_filename = f"conda-lock-{expected_dev_str}.lock"
+    assert (
+        output_file.name == expected_filename
+    ), f"Expected filename {expected_filename}, got {output_file.name}"
+
+    # Read the file contents
+    content = output_file.read_text()
+    assert "tzcode" in content, "Main category dependency should always be present"
+
+    # Check for dev category dependency
+    should_have_dev_category = (not dev_deps_are_empty) and (
+        (dev_deps is None or dev_deps is True)  # dev_dependencies is True by default
+        or "dev" in extras
+    )
+    does_have_dev_category = "pixi" in content
+    assert does_have_dev_category == should_have_dev_category, (
+        f"Dev category in lockfile: {does_have_dev_category}, "
+        f"Expected: {should_have_dev_category}"
+    )
+
+    # Check for custom extra category dependency
+    should_have_mm_category = "mm" in extras
+    does_have_mm_category = "micromamba" in content
+    assert does_have_mm_category == should_have_mm_category, (
+        f"Custom category (mm) in lockfile: {does_have_mm_category}, "
+        f"Expected: {should_have_mm_category}"
+    )