Merge PR #10 – Create current environment link when --print-deps-only has no env

https://github.com/fedora-python/tox-current-env/pull/10

README.rst

@@ -158,7 +158,8 @@ Don't mix current-env and regular tox runs
 
 Tox caches the virtualenvs it creates, and doesn't distinguish between
 regular virtualenvs and ``--current-env``.
-Don't mix ``tox --current-env`` runs and regular ``tox`` runs (without the flag).
+Don't mix ``tox --current-env`` or ``tox --print-deps-only`` runs
+and regular ``tox`` runs (without the flag).
 If you ever need to do this, use tox's ``--recreate/-r`` flag to clear the cache.
 
 The plugin should abort with a meaningful error message if this is detected,

src/tox_current_env/hooks.py

@@ -37,39 +37,6 @@ class InterpreterMismatch(tox.exception.InterpreterNotFound):
     """Interpreter version in current env does not match requested version"""
 
 
-@tox.hookimpl
-def tox_testenv_create(venv, action):
-    """We create a fake virtualenv with just the symbolic link"""
-    config = venv.envconfig.config
-    if config.option.print_deps_only:
-        # We don't need anything
-        return True
-    if config.option.current_env:
-        version_info = venv.envconfig.python_info.version_info
-        if version_info is None:
-            raise tox.exception.InterpreterNotFound(venv.envconfig.basepython)
-        if version_info[:2] != sys.version_info[:2]:
-            raise InterpreterMismatch(
-                f"tox_current_env: interpreter versions do not match:\n"
-                + f"    in current env: {tuple(sys.version_info)}\n"
-                + f"    requested: {version_info}"
-            )
-
-        # Make sure the `python` command on path is sys.executable.
-        # (We might have e.g. /usr/bin/python3, not `python`.)
-        # Remove the rest of the virtualenv.
-        link = venv.envconfig.get_envpython()
-        target = sys.executable
-        shutil.rmtree(os.path.dirname(os.path.dirname(link)), ignore_errors=True)
-        os.makedirs(os.path.dirname(link))
-        os.symlink(target, link)
-        return True
-    else:
-        link = venv.envconfig.get_envpython()
-        shutil.rmtree(os.path.dirname(os.path.dirname(link)), ignore_errors=True)
-        return None  # let tox handle the rest
-
-
 def _python_activate_exists(venv):
     python = venv.envconfig.get_envpython()
     bindir = os.path.dirname(python)
@@ -87,6 +54,11 @@ def is_proper_venv(venv):
     return python and activate
 
 
+def is_any_env(venv):
+    python, activate = _python_activate_exists(venv)
+    return python
+
+
 def unsupported_raise(config, venv):
     if config.option.recreate:
         return
@@ -101,6 +73,55 @@ def unsupported_raise(config, venv):
         )
 
 
+@tox.hookimpl
+def tox_testenv_create(venv, action):
+    """We create a fake virtualenv with just the symbolic link"""
+    config = venv.envconfig.config
+    create_fake_env = check_version = config.option.current_env
+    if config.option.print_deps_only:
+        if is_any_env(venv):
+            # We don't need anything
+            return True
+        else:
+            # We need at least some kind of environment,
+            # or tox fails without a python command
+            # We fallback to --current-env behavior,
+            # because it's cheaper, faster and won't install stuff
+            create_fake_env = True
+    if check_version:
+        # With real --current-env, we check this, but not with --print-deps-only only
+        version_info = venv.envconfig.python_info.version_info
+        if version_info is None:
+            raise tox.exception.InterpreterNotFound(venv.envconfig.basepython)
+        if version_info[:2] != sys.version_info[:2]:
+            raise InterpreterMismatch(
+                f"tox_current_env: interpreter versions do not match:\n"
+                + f"    in current env: {tuple(sys.version_info)}\n"
+                + f"    requested: {version_info}"
+            )
+    if create_fake_env:
+        # Make sure the `python` command on path is sys.executable.
+        # (We might have e.g. /usr/bin/python3, not `python`.)
+        # Remove the rest of the virtualenv.
+        link = venv.envconfig.get_envpython()
+        target = sys.executable
+        shutil.rmtree(os.path.dirname(os.path.dirname(link)), ignore_errors=True)
+        os.makedirs(os.path.dirname(link))
+        os.symlink(target, link)
+        return True
+    else:
+        link = venv.envconfig.get_envpython()
+        shutil.rmtree(os.path.dirname(os.path.dirname(link)), ignore_errors=True)
+        return None  # let tox handle the rest
+
+
+@tox.hookimpl
+def tox_package(session, venv):
+    """Fail early when unsupported"""
+    config = venv.envconfig.config
+    unsupported_raise(config, venv)
+
+
 @tox.hookimpl
 def tox_testenv_install_deps(venv, action):
     """We don't install anything"""

tests/test_integration.py

@@ -149,6 +149,22 @@ def test_regular_after_current_is_not_supported():
     assert "not supported" in result.stderr
 
 
+def test_regular_after_first_deps_only_is_not_supported():
+    result = tox("-e", NATIVE_TOXENV, "--print-deps-only")
+    assert result.stdout.splitlines()[0] == "six"
+    result = tox("-e", NATIVE_TOXENV, prune=False, check=False)
+    assert result.returncode > 0
+    assert "not supported" in result.stderr
+
+    # check that "test" was not installed to current environment
+    pip_freeze = subprocess.run(
+        (sys.executable, "-m", "pip", "freeze"),
+        encoding="utf-8",
+        stdout=subprocess.PIPE,
+    ).stdout.splitlines()
+    assert "test==0.0.0" not in pip_freeze
+
+
 def test_regular_recreate_after_current():
     result = tox("-e", NATIVE_TOXENV, "--current-env")
     assert result.stdout.splitlines()[0] == NATIVE_EXECUTABLE
@@ -184,14 +200,38 @@ def test_current_after_deps_only():
         assert result.stdout.splitlines()[0] == NATIVE_EXECUTABLE
 
 
-def test_regular_after_deps_only():
+def test_regular_recreate_after_deps_only():
     result = tox("-e", NATIVE_TOXENV, "--print-deps-only")
     assert "bin/python" not in result.stdout
     assert "six" in result.stdout
 
     result = tox("-re", NATIVE_TOXENV, prune=False)
     assert result.stdout.splitlines()[0] != NATIVE_EXECUTABLE
+    sitelib = DOT_TOX / f"{NATIVE_TOXENV}/lib/python3.{NATIVE_TOXENV[-1]}/site-packages"
+    assert sitelib.is_dir()
+    assert len(list(sitelib.glob("test-*.dist-info"))) == 1
 
     result = tox("-e", NATIVE_TOXENV, "--print-deps-only", prune=False)
     assert "bin/python" not in result.stdout
     assert "six" in result.stdout
+
+
+def test_print_deps_without_python_command(tmp_path):
+    bin = tmp_path / "bin"
+    bin.mkdir()
+    tox_link = bin / "tox"
+    tox_path = shutil.which("tox")
+    tox_link.symlink_to(tox_path)
+    env = {**os.environ, "PATH": str(bin)}
+
+    result = tox("-e", NATIVE_TOXENV, "--print-deps-only", env=env)
+    expected = textwrap.dedent(
+        f"""
+        six
+        py
+        ___________________________________ summary ____________________________________
+          {NATIVE_TOXENV}: commands succeeded
+          congratulations :)
+        """
+    ).lstrip()
+    assert result.stdout == expected