Skip missing interpreters (#71)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: RomainBrault

src/tox_uv/_venv.py

@@ -20,6 +20,7 @@
 
 from tox.execute.local_sub_process import LocalSubProcessExecutor
 from tox.execute.request import StdinSource
+from tox.tox_env.errors import Skip
 from tox.tox_env.python.api import Python, PythonInfo, VersionInfo
 from uv import find_uv_bin
 from virtualenv import app_data
@@ -68,7 +69,8 @@ def installer(self) -> Installer[Any]:
     def runs_on_platform(self) -> str:
         return sys.platform
 
-    def _get_python(self, base_python: list[str]) -> PythonInfo | None:  # noqa: PLR6301
+    @staticmethod
+    def _get_python(base_python: list[str]) -> PythonInfo | None:
         for base in base_python:  # pragma: no branch
             if base == sys.executable:
                 version_info = sys.version_info
@@ -113,6 +115,7 @@ def _get_python(self, base_python: list[str]) -> PythonInfo | None:  # noqa: PLR
                 platform=sys.platform,
                 extra={},
             )
+
         return None  # pragma: no cover
 
     @property
@@ -149,13 +152,19 @@ def create_python_env(self) -> None:
         else:
             uv_imp = "" if (imp and imp == "cpython") else imp
             version_spec = f"{uv_imp or ''}{base.major}.{base.minor}" if base.minor else f"{uv_imp or ''}{base.major}"
+
         cmd: list[str] = [self.uv, "venv", "-p", version_spec, "--allow-existing"]
         if self.options.verbosity > 2:  # noqa: PLR2004
             cmd.append("-v")
         if self.conf["uv_seed"]:
             cmd.append("--seed")
         cmd.append(str(self.venv_dir))
         outcome = self.execute(cmd, stdin=StdinSource.OFF, run_id="venv", show=None)
+
+        if self.core["skip_missing_interpreters"] and outcome.exit_code == 1:
+            msg = "could not find python interpreter with spec(s):" f" {version_spec}"
+            raise Skip(msg)
+
         outcome.assert_success()
         self._created = True
 

tests/test_tox_uv_venv.py

@@ -115,11 +115,33 @@ def test_uv_venv_spec_abs_path_conflict_platform(
 
 
 def test_uv_venv_na(tox_project: ToxProjectCreator) -> None:
+    # skip_missing_interpreters is true by default
     project = tox_project({"tox.ini": "[testenv]\npackage=skip\nbase_python=1.0"})
     result = project.run("-vv")
+
+    # When a Python interpreter is missing in a pytest environment, project.run
+    # return code is equal to -1
+    result.assert_failed(code=-1)
+
+
+def test_uv_venv_skip_missing_interpreters_fail(tox_project: ToxProjectCreator) -> None:
+    project = tox_project({
+        "tox.ini": "[tox]\nskip_missing_interpreters=false\n[testenv]\npackage=skip\nbase_python=1.0"
+    })
+    result = project.run("-vv")
     result.assert_failed(code=1)
 
 
+def test_uv_venv_skip_missing_interpreters_pass(tox_project: ToxProjectCreator) -> None:
+    project = tox_project({
+        "tox.ini": "[tox]\nskip_missing_interpreters=true\n[testenv]\npackage=skip\nbase_python=1.0"
+    })
+    result = project.run("-vv")
+    # When a Python interpreter is missing in a pytest environment, project.run
+    # return code is equal to -1
+    result.assert_failed(code=-1)
+
+
 def test_uv_venv_platform_check(tox_project: ToxProjectCreator) -> None:
     project = tox_project({"tox.ini": f"[testenv]\nplatform={sys.platform}\npackage=skip"})
     result = project.run("-vv")