test_venv.py

# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt

"""Tests about understanding how third-party code is installed."""

import os
import os.path
import shutil

import pytest

from coverage import env

from tests.coveragetest import CoverageTest, TESTS_DIR
from tests.helpers import change_dir, make_file, nice_file
from tests.helpers import re_lines, run_command


def run_in_venv(cmd):
    r"""Run `cmd` in the virtualenv at `venv`.

    The first word of the command will be adjusted to run it from the
    venv/bin or venv\Scripts directory.

    Returns the text output of the command.
    """
    words = cmd.split()
    if env.WINDOWS:
        words[0] = fr"venv\Scripts\{words[0]}.exe"
    else:
        words[0] = fr"venv/bin/{words[0]}"
    status, output = run_command(" ".join(words))
    assert status == 0
    return output


@pytest.fixture(scope="session", name="venv_world")
def venv_world_fixture(tmp_path_factory):
    """Create a virtualenv with a few test packages for VirtualenvTest to use.

    Returns the directory containing the "venv" virtualenv.
    """

    venv_world = tmp_path_factory.mktemp("venv_world")
    with change_dir(venv_world):
        # Create a virtualenv.
        run_command("python -m venv venv")

        # A third-party package that installs a few different packages.
        make_file("third_pkg/third/__init__.py", """\
            import fourth
            def third(x):
                return 3 * x
            """)
        # Use plugin2.py as third.plugin
        with open(os.path.join(os.path.dirname(__file__), "plugin2.py")) as f:
            make_file("third_pkg/third/plugin.py", f.read())
        # A render function for plugin2 to use for dynamic file names.
        make_file("third_pkg/third/render.py", """\
            def render(filename, linenum):
                return "HTML: {}@{}".format(filename, linenum)
            """)
        # Another package that third can use.
        make_file("third_pkg/fourth/__init__.py", """\
            def fourth(x):
                return 4 * x
            """)
        # Some namespace packages.
        make_file("third_pkg/nspkg/fifth/__init__.py", """\
            def fifth(x):
                return 5 * x
            """)
        # The setup.py to install everything.
        make_file("third_pkg/setup.py", """\
            import setuptools
            setuptools.setup(
                name="third",
                packages=["third", "fourth", "nspkg.fifth"],
            )
            """)

        # Some namespace packages.
        make_file("another_pkg/nspkg/sixth/__init__.py", """\
            def sixth(x):
                return 6 * x
            """)
        make_file("another_pkg/setup.py", """\
            import setuptools
            setuptools.setup(
                name="another",
                packages=["nspkg.sixth"],
            )
            """)

        # Bug888 code.
        make_file("bug888/app/setup.py", """\
            from setuptools import setup
            setup(
                name='testcov',
                packages=['testcov'],
                namespace_packages=['testcov'],
            )
            """)
        make_file("bug888/app/testcov/__init__.py", """\
            try:  # pragma: no cover
                __import__('pkg_resources').declare_namespace(__name__)
            except ImportError:  # pragma: no cover
                from pkgutil import extend_path
                __path__ = extend_path(__path__, __name__)
            """)
        make_file("bug888/app/testcov/main.py", """\
            import pkg_resources
            for entry_point in pkg_resources.iter_entry_points('plugins'):
                entry_point.load()()
            """)
        make_file("bug888/plugin/setup.py", """\
            from setuptools import setup
            setup(
                name='testcov-plugin',
                packages=['testcov'],
                namespace_packages=['testcov'],
                entry_points={'plugins': ['testp = testcov.plugin:testp']},
            )
            """)
        make_file("bug888/plugin/testcov/__init__.py", """\
            try:  # pragma: no cover
                __import__('pkg_resources').declare_namespace(__name__)
            except ImportError:  # pragma: no cover
                from pkgutil import extend_path
                __path__ = extend_path(__path__, __name__)
            """)
        make_file("bug888/plugin/testcov/plugin.py", """\
            def testp():
                print("Plugin here")
            """)

        # Install the third-party packages.
        run_in_venv("python -m pip install --no-index ./third_pkg")
        run_in_venv("python -m pip install --no-index -e ./another_pkg")
        run_in_venv("python -m pip install --no-index -e ./bug888/app -e ./bug888/plugin")
        shutil.rmtree("third_pkg")

        # Install coverage.
        coverage_src = nice_file(TESTS_DIR, "..")
        run_in_venv(f"python -m pip install --no-index {coverage_src}")

    return venv_world


@pytest.fixture(params=[
    "coverage",
    "python -m coverage",
], name="coverage_command")
def coverage_command_fixture(request):
    """Parametrized fixture to use multiple forms of "coverage" command."""
    return request.param


class VirtualenvTest(CoverageTest):
    """Tests of virtualenv considerations."""

    expected_stdout = "33\n110\n198\n1.5\n"

    @pytest.fixture(autouse=True)
    def in_venv_world_fixture(self, venv_world):
        """For running tests inside venv_world, and cleaning up made files."""
        with change_dir(venv_world):
            self.make_file("myproduct.py", """\
                import colorsys
                import third
                import nspkg.fifth
                import nspkg.sixth
                print(third.third(11))
                print(nspkg.fifth.fifth(22))
                print(nspkg.sixth.sixth(33))
                print(sum(colorsys.rgb_to_hls(1, 0, 0)))
                """)

            self.del_environ("COVERAGE_TESTING")    # To avoid needing contracts installed.
            self.set_environ("COVERAGE_DEBUG_FILE", "debug_out.txt")
            self.set_environ("COVERAGE_DEBUG", "trace")

            yield

            for fname in os.listdir("."):
                if fname not in {"venv", "another_pkg", "bug888"}:
                    os.remove(fname)

    def get_trace_output(self):
        """Get the debug output of coverage.py"""
        with open("debug_out.txt") as f:
            return f.read()

    def test_third_party_venv_isnt_measured(self, coverage_command):
        out = run_in_venv(coverage_command + " run --source=. myproduct.py")
        # In particular, this warning doesn't appear:
        # Already imported a file that will be measured: .../coverage/__main__.py
        assert out == self.expected_stdout

        # Check that our tracing was accurate. Files are mentioned because
        # --source refers to a file.
        debug_out = self.get_trace_output()
        assert re_lines(
            r"^Not tracing .*\bexecfile.py': inside --source, but is third-party",
            debug_out,
            )
        assert re_lines(r"^Tracing .*\bmyproduct.py", debug_out)
        assert re_lines(
            r"^Not tracing .*\bcolorsys.py': falls outside the --source spec",
            debug_out,
            )

        out = run_in_venv("python -m coverage report")
        assert "myproduct.py" in out
        assert "third" not in out
        assert "coverage" not in out
        assert "colorsys" not in out

    def test_us_in_venv_isnt_measured(self, coverage_command):
        out = run_in_venv(coverage_command + " run --source=third myproduct.py")
        assert out == self.expected_stdout

        # Check that our tracing was accurate. Modules are mentioned because
        # --source refers to a module.
        debug_out = self.get_trace_output()
        assert re_lines(
            r"^Not tracing .*\bexecfile.py': " +
            "module 'coverage.execfile' falls outside the --source spec",
            debug_out,
            )
        assert re_lines(
            r"^Not tracing .*\bmyproduct.py': module 'myproduct' falls outside the --source spec",
            debug_out,
            )
        assert re_lines(
            r"^Not tracing .*\bcolorsys.py': module 'colorsys' falls outside the --source spec",
            debug_out,
            )

        out = run_in_venv("python -m coverage report")
        assert "myproduct.py" not in out
        assert "third" in out
        assert "coverage" not in out
        assert "colorsys" not in out

    def test_venv_isnt_measured(self, coverage_command):
        out = run_in_venv(coverage_command + " run myproduct.py")
        assert out == self.expected_stdout

        debug_out = self.get_trace_output()
        assert re_lines(r"^Not tracing .*\bexecfile.py': is part of coverage.py", debug_out)
        assert re_lines(r"^Tracing .*\bmyproduct.py", debug_out)
        assert re_lines(r"^Not tracing .*\bcolorsys.py': is in the stdlib", debug_out)

        out = run_in_venv("python -m coverage report")
        assert "myproduct.py" in out
        assert "third" not in out
        assert "coverage" not in out
        assert "colorsys" not in out

    @pytest.mark.skipif(not env.C_TRACER, reason="Plugins are only supported with the C tracer.")
    def test_venv_with_dynamic_plugin(self, coverage_command):
        # https://github.com/nedbat/coveragepy/issues/1150
        # Django coverage plugin was incorrectly getting warnings:
        # "Already imported: ... django/template/blah.py"
        # It happened because coverage imported the plugin, which imported
        # Django, and then the Django files were reported as traceable.
        self.make_file(".coveragerc", "[run]\nplugins=third.plugin\n")
        self.make_file("myrender.py", """\
            import third.render
            print(third.render.render("hello.html", 1723))
            """)
        out = run_in_venv(coverage_command + " run --source=. myrender.py")
        # The output should not have this warning:
        # Already imported a file that will be measured: ...third/render.py (already-imported)
        assert out == "HTML: hello.html@1723\n"

    def test_installed_namespace_packages(self, coverage_command):
        # https://github.com/nedbat/coveragepy/issues/1231
        # When namespace packages were installed, they were considered
        # third-party packages.  Test that isn't still happening.
        out = run_in_venv(coverage_command + " run --source=nspkg myproduct.py")
        # In particular, this warning doesn't appear:
        # Already imported a file that will be measured: .../coverage/__main__.py
        assert out == self.expected_stdout

        # Check that our tracing was accurate. Files are mentioned because
        # --source refers to a file.
        debug_out = self.get_trace_output()
        assert re_lines(
            r"^Not tracing .*\bexecfile.py': " +
            "module 'coverage.execfile' falls outside the --source spec",
            debug_out,
            )
        assert re_lines(
            r"^Not tracing .*\bmyproduct.py': module 'myproduct' falls outside the --source spec",
            debug_out,
            )
        assert re_lines(
            r"^Not tracing .*\bcolorsys.py': module 'colorsys' falls outside the --source spec",
            debug_out,
            )

        out = run_in_venv("python -m coverage report")

        # Name                                                       Stmts   Miss  Cover
        # ------------------------------------------------------------------------------
        # another_pkg/nspkg/sixth/__init__.py                            2      0   100%
        # venv/lib/python3.9/site-packages/nspkg/fifth/__init__.py       2      0   100%
        # ------------------------------------------------------------------------------
        # TOTAL                                                          4      0   100%

        assert "myproduct.py" not in out
        assert "third" not in out
        assert "coverage" not in out
        assert "colorsys" not in out
        assert "fifth" in out
        assert "sixth" in out

    def test_bug888(self, coverage_command):
        out = run_in_venv(
            coverage_command +
            " run --source=bug888/app,bug888/plugin bug888/app/testcov/main.py"
            )
        # When the test fails, the output includes "Already imported a file that will be measured"
        assert out == "Plugin here\n"