Update node name matcher (#282)

* Make slash prefix for node name matching optional

The node name must be fully qualified, with a namespace, for matching.
This change makes the slash optional for convenience.
For example, the following two calls are now equivalent:

    matches_node_name('/foo')
    matches_node_name('foo')

Signed-off-by: Jacob Perron <[email protected]>

* Move node name matcher into matchers module

The matcher function 'matches_node_name' is not specific to lifecycle nodes,
so it makes sense for it to live in a more general module.

Add a deprecation warning to the matcher in the lifecycle module.

Signed-off-by: Jacob Perron <[email protected]>

* Add tests for matcher

Signed-off-by: Jacob Perron <[email protected]>

* Move into matchers folder

Signed-off-by: Jacob Perron <[email protected]>

Author: jacobperron

launch_ros/launch_ros/events/__init__.py

@@ -15,7 +15,9 @@
 """events Module."""
 
 from . import lifecycle
+from .matchers import matches_node_name
 
 __all__ = [
     'lifecycle',
+    'matches_node_name',
 ]

launch_ros/launch_ros/events/lifecycle/lifecycle_node_matchers.py

@@ -16,6 +16,9 @@
 
 from typing import Callable
 from typing import Text
+import warnings
+
+from ..matchers import matches_node_name as _matches_node_name
 
 if False:
     # imports here would cause loops, but are only used as forward-references for type-checking
@@ -24,4 +27,8 @@
 
 def matches_node_name(node_name: Text) -> Callable[['LifecycleNode'], bool]:
     """Return a matcher which matches based on the name of the node itself."""
-    return lambda action: action.node_name == node_name
+    warnings.warn(
+        "'matches_node_name' has been moved into the 'launch.events' module and will be removed "
+        "from the 'lifecycle' module in the future"
+    )
+    return _matches_node_name(node_name)

launch_ros/launch_ros/events/matchers/__init__.py

@@ -0,0 +1,21 @@
+# Copyright 2021 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""events.matchers module."""
+
+from .matches_node_name import matches_node_name
+
+__all__ = [
+    'matches_node_name',
+]

launch_ros/launch_ros/events/matchers/matches_node_name.py

@@ -0,0 +1,29 @@
+# Copyright 2018 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Matchers for node names."""
+
+from typing import Callable
+from typing import Text
+
+if False:
+    # imports here would cause loops, but are only used as forward-references for type-checking
+    from ..actions import Node  # noqa: F401
+
+
+def matches_node_name(node_name: Text) -> Callable[['Node'], bool]:
+    """Return a matcher which matches based on the name of the node itself."""
+    if not node_name.startswith('/'):
+        node_name = f'/{node_name}'
+    return lambda action: action.node_name == node_name

test_launch_ros/test/test_launch_ros/events/test_matchers.py

@@ -0,0 +1,38 @@
+# Copyright 2021 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for the matchers module."""
+
+from launch_ros.events import matches_node_name
+
+
+class MockNode:
+    """Mock node action."""
+
+    def __init__(self, node_name):
+        self.node_name = node_name
+
+
+def test_matches_node_name():
+    """Test the matches_node_name function."""
+    matcher = matches_node_name('/foo')
+
+    assert matcher(MockNode('/foo'))
+    assert not matcher(MockNode('/foo/bar'))
+
+    # Without '/' prefix
+    matcher = matches_node_name('foo')
+
+    assert matcher(MockNode('/foo'))
+    assert not matcher(MockNode('/foo/bar'))