pytestplugin: make "target" a parametrized fixture

This allows users to run their pytest test scripts with an
LG_ENV/--lg-env that has multiple targets instead of forcing the user to
define one named "main" in order to run the tests.

One of the downsides of this implementation is that autogenerated doc
wouldn't define the "target" fixture anymore as it is entirely
programmatically defined.

Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>

Author: QSchulz

labgrid/pytestplugin/__init__.py

@@ -1,2 +1,2 @@
-from .fixtures import pytest_addoption, env, target, strategy
+from .fixtures import pytest_addoption, env, pytest_generate_tests, strategy
 from .hooks import pytest_configure, pytest_collection_modifyitems, pytest_cmdline_main

labgrid/pytestplugin/fixtures.py

@@ -56,6 +56,38 @@ def pytest_addoption(parser):
     parser.addini("log_format", default=DEFAULT_FORMAT, help="Default value for log_format (overwritten by labgrid)")
 
 
+def pytest_generate_tests(metafunc):
+    # Support running all tests from passed pytest files/directories for all
+    # targets by generating a parametrized "target" fixture based on the name
+    # of all targets in the passed lg_env file.
+    if "target" in metafunc.fixturenames:
+        env = metafunc.config.stash[LABGRID_ENV_KEY]
+
+        if not env:
+            pytest.skip("missing environment config (use --lg-env)")
+
+        env_targets = list(env.config.get_targets().keys())
+
+        targets = []
+
+        for target_name in env_targets:
+            target = env.get_target(target_name)
+            if target is None:
+                raise UserError(f"Using target fixture without '{target_name}' target in config")
+
+            targets.append(target)
+
+        metafunc.parametrize("target", targets, scope="session", ids=env_targets)
+
+# This session fixture is programmatically defined within pytest_generate_tests
+# just above.
+#
+# @pytest.fixture(scope="session")
+# def target():
+#     """Return the Target to run the test against
+#     """
+#     pass
+
 @pytest.fixture(scope="session")
 def env(request, record_testsuite_property):
     """Return the environment configured in the supplied configuration file.
@@ -116,17 +148,6 @@ def env(request, record_testsuite_property):
     sshmanager.close_all()
 
 
-@pytest.fixture(scope="session")
-def target(env):
-    """Return the default target `main` configured in the supplied
-    configuration file."""
-    target = env.get_target()
-    if target is None:
-        raise UserError("Using target fixture without 'main' target in config")
-
-    return target
-
-
 @pytest.fixture(scope="session")
 def strategy(request, target):
     """Return the Strategy of the default target `main` configured in the