Advise to use spin run python when doing spin run foo.py

Author: stefanv

spin/tests/test_build_cmds.py

@@ -1,24 +1,42 @@
 import subprocess
+import sys
+import tempfile
 from pathlib import Path
 
+import pytest
+
 import spin as libspin
 from spin.cmds.util import run
 
+skip_on_windows = pytest.mark.skipif(
+    sys.platform.startswith("win"), reason="Skipped on Windows"
+)
+
 
 def spin(*args):
-    return run(["spin"] + list(args), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    return run(
+        ["spin"] + list(args),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        sys_exit=False,
+    )
 
 
 def stdout(p):
     return p.stdout.decode("utf-8").strip()
 
 
+def stderr(p):
+    return p.stderr.decode("utf-8").strip()
+
+
 def test_get_version():
     p = spin("--version")
     assert stdout(p) == f"spin {libspin.__version__}"
 
 
 def test_basic_build():
+    """Does the package build?"""
     spin("build")
 
     assert Path("build").exists(), "`build` folder not created after `spin build`"
@@ -28,20 +46,23 @@ def test_basic_build():
 
 
 def test_debug_builds():
+    """Does spin generate gcov debug output files?"""
     spin("build", "--gcov")
 
     debug_files = Path(".").rglob("*.gcno")
     assert len(list(debug_files)) != 0, "debug files not generated for gcov build"
 
 
 def test_expand_pythonpath():
+    """Does an $ENV_VAR get expanded in `spin run`?"""
     output = spin("run", "echo $PYTHONPATH")
     assert any(
         p in stdout(output) for p in ("site-packages", "dist-packages")
     ), f"Expected value of $PYTHONPATH, got {stdout(output)} instead"
 
 
 def test_run_stdout():
+    """Ensure `spin run` only includes command output on stdout."""
     p = spin(
         "run",
         "python",
@@ -54,10 +75,23 @@ def test_run_stdout():
 
 
 def test_editable_conflict():
+    """Do we warn when a conflicting editable install is present?"""
     try:
         run(["pip", "install", "--quiet", "-e", "."])
         assert "Warning! An editable installation" in stdout(
             spin("run", "ls")
         ), "Failed to detect and warn about editable install"
     finally:
         run(["pip", "uninstall", "--quiet", "-y", "example_pkg"])
+
+
+# Detecting whether a file is executable is not that easy on Windows,
+# as it seems to take into consideration whether that file is associated as an executable.
+@skip_on_windows
+def test_recommend_run_python():
+    """If `spin run file.py` is called, is `spin run python file.py` recommended?"""
+    with tempfile.NamedTemporaryFile(suffix=".py") as f:
+        p = spin("run", f.name)
+        assert "Did you mean to call" in stdout(
+            p
+        ), "Failed to recommend `python run python file.py`"