allow running pytest directly

Author: thorsten-klein

pyproject.toml

@@ -115,3 +115,6 @@ env = {PYTHONIOENCODING = "utf-8"}
 lint = "ruff check ."
 types = "mypy --package west"
 all = ["test", "lint", "types"]
+
+[tool.pytest.ini_options]
+pythonpath = ["src"]

src/west/app/main.py

@@ -30,6 +30,12 @@
 
 import colorama
 
+if __name__ == "__main__":
+    # Prepend the project root to sys.path so that running this script
+    # directly uses the local 'west' modules instead of any installed version.
+    project_root = Path(__file__).resolve().parents[2]
+    sys.path.insert(0, os.fspath(project_root))
+
 import west.configuration
 from west import log
 from west.app.config import Config

tests/conftest.py

@@ -13,7 +13,24 @@
 
 import pytest
 
+import west.version
 from west import configuration as config
+from west.app import main
+
+# Expected PYTHONPATH pointing to the current source directory
+PYTHONPATH = os.fspath(Path(west.version.__file__).resolve().parents[1])
+
+# West's main Python script, runnable as a command-line executable
+WEST_MAIN = main.__file__
+
+# installed west executable (only set if it is correct version)
+WEST_EXE = shutil.which('west')
+if WEST_EXE:
+    # ensure that installed west exe has expected version
+    expected = west.version.__version__
+    actual = subprocess.check_output([WEST_EXE,'--version'], text=True)
+    if expected not in actual:
+        WEST_EXE = None
 
 GIT = shutil.which('git')
 
@@ -324,17 +341,21 @@ def cmd(cmd, cwd=None, stderr=None, env=None):
     #
     # This helper relies on the test environment to ensure that the
     # 'west' executable is a bootstrapper installed from the current
-    # west source code.
+    # west source code. If installed 'west' executable has correct version,
+    # it is preferred. Otherwise, fall back to running the local Python module.
     #
     # stdout from cmd is captured and returned. The command is run in
     # a python subprocess so that program-level setup and teardown
     # happen fresh.
 
     # If you have quoting issues: do NOT quote. It's not portable.
     # Instead, pass `cmd` as a list.
-    cmd = ['west'] + (cmd.split() if isinstance(cmd, str) else cmd)
 
+    west_exe = WEST_EXE or WEST_MAIN
+
+    cmd = [west_exe] + (cmd.split() if isinstance(cmd, str) else cmd)
     print('running:', cmd)
+
     if env:
         print('with non-default environment:')
         for k in env:
@@ -349,7 +370,7 @@ def cmd(cmd, cwd=None, stderr=None, env=None):
     try:
         return check_output(cmd, cwd=cwd, stderr=stderr, env=env)
     except subprocess.CalledProcessError:
-        print('cmd: west:', shutil.which('west'), file=sys.stderr)
+        print('cmd: west:', west_exe, file=sys.stderr)
         raise
 
 

tests/test_main.py

@@ -1,6 +1,9 @@
+import os
 import subprocess
 import sys
 
+from conftest import PYTHONPATH, WEST_EXE, cmd
+
 import west.version
 
 
@@ -11,8 +14,26 @@ def test_main():
     # sane (i.e. the actual version number is printed instead of
     # simply an error message to stderr).
 
-    output_as_module = subprocess.check_output([sys.executable, '-m', 'west',
-                                                '--version']).decode()
-    output_directly = subprocess.check_output(['west', '--version']).decode()
-    assert west.version.__version__ in output_as_module
-    assert output_as_module == output_directly
+    expected_version = west.version.__version__
+
+    # call west executable directly
+    output_directly = cmd(['--version'])
+    assert expected_version in output_directly
+
+    # Note: if a wrong west version is installed, local PYTHONPATH needs to be
+    # prepended so that the called process uses correct west python modules
+    env = os.environ.copy()
+    if not WEST_EXE:
+        val = os.getenv('PYTHONPATH')
+        env['PYTHONPATH'] = f'{PYTHONPATH}{os.pathsep}{val}' if val else PYTHONPATH
+
+    # execute west as a python module
+    output_as_module = subprocess.check_output(
+        [sys.executable, '-m', 'west','--version'],
+        env=env,
+        text=True
+    )
+    assert expected_version in output_as_module
+
+    # output must be same in both cases
+    assert output_as_module.rstrip() == output_directly.rstrip()