Teach poetry run to find .cmd scripts on Windows

poetry/utils/env.py

@@ -1123,8 +1123,7 @@ def _bin(self, bin):  # type: (str) -> str
         """
         Return path to the given executable.
         """
-        bin_path = (self._bin_dir / bin).with_suffix(".exe" if self._is_windows else "")
-        if not bin_path.exists():
+        if self._is_windows:
             # On Windows, some executables can be in the base path
             # This is especially true when installing Python with
             # the official installer, where python.exe will be at
@@ -1133,14 +1132,25 @@ def _bin(self, bin):  # type: (str) -> str
             # in normal uses but this happens in the sonnet script
             # that creates a fake virtual environment pointing to
             # a base Python install.
-            if self._is_windows:
-                bin_path = (self._path / bin).with_suffix(".exe")
-                if bin_path.exists():
-                    return str(bin_path)
+            # On windows we also need to manually search the %PATH%
+            # as the OS won't do it for us.
+            # Note: shutil.which always searches the current
+            # directory first on windows, This is the behavior
+            # windows users will expect.
+            search_path = os.pathsep.join(
+                (str(self._bin_dir), str(self._path), os.environ["PATH"])
+            )
+            found = shutil.which(bin, path=search_path)
+            if found:
+                return found
 
-            return bin
+        bin_path = self._bin_dir / bin
 
-        return str(bin_path)
+        if bin_path.exists():
+            return str(bin_path)
+
+        # Return original path if our search failed.
+        return bin
 
     def __eq__(self, other):  # type: (Env) -> bool
         return other.__class__ == self.__class__ and other.path == self.path

tests/console/commands/test_run.py

@@ -1,5 +1,11 @@
+import os
+import tempfile
+
 import pytest
 
+from poetry.utils._compat import WINDOWS
+from poetry.utils._compat import Path
+
 
 @pytest.fixture
 def tester(command_tester_factory):
@@ -14,3 +20,89 @@ def patches(mocker, env):
 def test_run_passes_all_args(tester, env):
     tester.execute("python -V")
     assert [["python", "-V"]] == env.executed
+
+
+@pytest.mark.skipif(
+    not WINDOWS, reason="This test asserts Windows-specific compatibility",
+)
+def test_run_console_scripts_on_windows(tmp_venv, command_tester_factory, mocker):
+    """Test that `poetry run` on Windows finds console scripts.
+
+    On Windows, Poetry installs console scripts of editable
+    dependencies by creating in the `Scripts/` directory both:
+
+    1. The Bash script one expects on Linux (an extension-less file),
+    with a shebang to launch Python, import the given module, and call
+    the given function.
+
+    2. A Batch script (with the `.cmd` file extension) which makes
+    this Bash script work on Windows by calling Python directly and
+    then executing the script from (1).
+
+    This works because Windows programs (like the command prompt,
+    PowerShell, "run" box, `start`, `where`, etc.) know to append
+    extensions from the `PATHEXT` environment variable when looking
+    for named programs. This is the Windows version of `chmod +x`.
+    Sine Poetry is cross-platform, `poetry run` also needs to look for
+    programs with this algorithm, and so this is a regression test.
+
+    This test asserts that you can a console script via `poetry run`
+    just by providing its name without the `.cmd` extension (the
+    common use case).
+
+    """
+    new_environ = {}
+    new_environ.update(os.environ)
+    new_environ["PATHEXT"] = ".BAT;.CMD"  # ensure environ vars are deterministic
+    mocker.patch("os.environ", new_environ)
+
+    tester = command_tester_factory("run", environment=tmp_venv)
+    bat_script = tmp_venv._bin_dir / "console_script.bat"
+    cmd_script = tmp_venv._bin_dir / "console_script.cmd"
+
+    cmd_script.write_text("exit 15")
+    bat_script.write_text("exit 30")
+    assert tester.execute("console_script") == 30
+    assert tester.execute("console_script.bat") == 30
+    assert tester.execute("console_script.cmd") == 15
+
+
+@pytest.mark.skipif(
+    not WINDOWS, reason="This test asserts Windows-specific compatibility",
+)
+def test_script_external_to_env(tmp_venv, command_tester_factory, mocker):
+    """
+    If a script exists on the path outside poetry, or in the current directory,
+    poetry run should still work
+    """
+    new_environ = {}
+    new_environ.update(os.environ)
+
+    tester = command_tester_factory("run", environment=tmp_venv)
+
+    # create directory and add it to the PATH
+    with tempfile.TemporaryDirectory() as tmp_dir_name:
+        # add script to current directory
+        script_in_cur_dir = tempfile.NamedTemporaryFile(
+            "w", dir=".", suffix=".CMD", delete=False
+        )
+        script_in_cur_dir.write("exit 30")
+        script_in_cur_dir.close()
+
+        try:
+            # add script to the new directory
+            script = Path(tmp_dir_name) / "console_script.cmd"
+            script.write_text("exit 15")
+
+            new_environ[
+                "PATHEXT"
+            ] = ".BAT;.CMD"  # ensure environ vars are deterministic
+            new_environ["PATH"] = os.environ["PATH"] + os.pathsep + tmp_dir_name
+            mocker.patch("os.environ", new_environ)
+
+            # poetry run will find it as it searched the path
+            assert tester.execute("console_script") == 15
+            assert tester.execute(script_in_cur_dir.name) == 30
+
+        finally:
+            os.unlink(script_in_cur_dir.name)