[backport humble] Make the directory-finding substitutions into a PathSubstitution for / operator (backport #914)

launch/launch/logging/__init__.py

@@ -24,14 +24,10 @@
 import socket
 import sys
 
-from typing import Iterable
 from typing import List
 
 from . import handlers
 
-from ..frontend import expose_substitution
-from ..some_substitutions_type import SomeSubstitutionsType
-from ..substitutions import TextSubstitution
 
 __all__ = [
     'get_logger',
@@ -305,13 +301,6 @@ def get_logger(name=None):
     return logger
 
 
-@expose_substitution('log_dir')
-def _log_dir(data: Iterable[SomeSubstitutionsType]):
-    if len(data) > 0:
-        raise ValueError('log_dir substitution does not expect any arguments')
-    return TextSubstitution, {'text': launch_config.log_dir}
-
-
 def _normalize_output_configuration(config):
     """
     Normalize output configuration to a dict representation.

launch/launch/substitutions/__init__.py

@@ -27,6 +27,7 @@
 from .find_executable import FindExecutable
 from .if_else_substitution import IfElseSubstitution
 from .launch_configuration import LaunchConfiguration
+from .launch_log_dir import LaunchLogDir
 from .local_substitution import LocalSubstitution
 from .not_equals_substitution import NotEqualsSubstitution
 from .path_join_substitution import PathJoinSubstitution
@@ -49,6 +50,7 @@
     'FindExecutable',
     'IfElseSubstitution',
     'LaunchConfiguration',
+    'LaunchLogDir',
     'LocalSubstitution',
     'NotSubstitution',
     'NotEqualsSubstitution',

launch/launch/substitutions/launch_log_dir.py

@@ -0,0 +1,54 @@
+# Copyright 2022 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.
+
+"""Module for the LaunchLogDir substitution."""
+
+from typing import Any
+from typing import Dict
+from typing import Sequence
+from typing import Text
+from typing import Tuple
+from typing import Type
+
+from .path_join_substitution import PathSubstitution
+from ..frontend.expose import expose_substitution
+from ..launch_context import LaunchContext
+from ..logging import launch_config as launch_logging_config
+from ..some_substitutions_type import SomeSubstitutionsType
+
+
+@expose_substitution('launch_log_dir')
+@expose_substitution('log_dir')
+class LaunchLogDir(PathSubstitution):
+    """Substitution that returns the absolute path to the current launch log directory."""
+
+    def __init__(self) -> None:
+        """Create a LaunchLogDir substitution."""
+        super().__init__(path=self)
+
+    @classmethod
+    def parse(cls, data: Sequence[SomeSubstitutionsType]
+              ) -> Tuple[Type['LaunchLogDir'], Dict[Any, Any]]:
+        """Parse `LaunchLogDir` substitution."""
+        if len(data) != 0:
+            raise TypeError("launch_log_dir/log_dir substitution doesn't expect arguments")
+        return cls, {}
+
+    def describe(self) -> Text:
+        """Return a description of this substitution as a string."""
+        return 'LaunchLogDir()'
+
+    def perform(self, context: LaunchContext) -> Text:
+        """Perform the substitution by returning the path to the current launch log directory."""
+        return launch_logging_config.log_dir

launch/launch/substitutions/this_launch_file_dir.py

@@ -17,20 +17,20 @@
 from typing import Iterable
 from typing import Text
 
+from .path_join_substitution import PathSubstitution
 from .substitution_failure import SubstitutionFailure
 from ..frontend.expose import expose_substitution
 from ..launch_context import LaunchContext
 from ..some_substitutions_type import SomeSubstitutionsType
-from ..substitution import Substitution
 
 
 @expose_substitution('dirname')
-class ThisLaunchFileDir(Substitution):
+class ThisLaunchFileDir(PathSubstitution):
     """Substitution that returns the absolute path to the current launch file."""
 
     def __init__(self) -> None:
         """Create a ThisLaunchFileDir substitution."""
-        super().__init__()
+        super().__init__(path=self)
 
     @classmethod
     def parse(cls, data: Iterable[SomeSubstitutionsType]):

launch/test/launch/substitutions/test_launch_log_dir.py

@@ -0,0 +1,49 @@
+# Copyright 2022 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 LaunchLogDir substitution class."""
+
+from launch import LaunchContext
+from launch.frontend.parse_substitution import parse_substitution
+from launch.substitutions import LaunchLogDir
+
+
+def test_launch_log_dir():
+    """Test the constructors for LaunchLogDir class."""
+    LaunchLogDir()
+
+
+def test_launch_log_dir_methods():
+    """Test the methods of the LaunchLogDir class."""
+    lld = LaunchLogDir()
+
+    lc = LaunchContext()
+    assert lld.perform(lc)
+
+
+def test_launch_log_dir_path():
+    test_dir = LaunchLogDir() / 'subdir'
+    lc = LaunchContext()
+    result = test_dir.perform(lc)
+    assert result
+    assert result.endswith('subdir')
+
+
+def test_launch_log_dir_frontend():
+    """Test launch_log_dir/log_dir frontend substitutions."""
+    for sub in ('launch_log_dir', 'log_dir'):
+        subst = parse_substitution(f'$({sub})')
+        assert len(subst) == 1
+        result = subst[0]
+        assert isinstance(result, LaunchLogDir)

launch/test/launch/substitutions/test_this_launch_file_dir.py

@@ -14,6 +14,8 @@
 
 """Tests for the ThisLaunchFileDir substitution class."""
 
+import os
+
 from launch import LaunchContext
 from launch.substitutions import SubstitutionFailure
 from launch.substitutions import ThisLaunchFileDir
@@ -35,3 +37,10 @@ def test_this_launch_file_path_methods():
         tlfp.perform(lc)
     lc.extend_locals({'current_launch_file_directory': 'foo'})
     assert tlfp.perform(lc) == 'foo'
+
+
+def test_this_launch_file_dir_pathing():
+    test_file = ThisLaunchFileDir() / 'some_launch.xml'
+    lc = LaunchContext()
+    lc.extend_locals({'current_launch_file_directory': 'foo'})
+    assert test_file.perform(lc) == os.path.join('foo', 'some_launch.xml')

launch/test/launch/test_logging.py

@@ -22,7 +22,7 @@
 
 from launch.frontend.parse_substitution import parse_substitution
 import launch.logging
-from launch.substitutions import TextSubstitution
+from launch.substitutions import LaunchLogDir
 
 import pytest
 
@@ -333,5 +333,4 @@ def test_get_log_dir_frontend(log_dir):
     subst = parse_substitution('$(log_dir)')
     assert len(subst) == 1
     result = subst[0]
-    assert isinstance(result, TextSubstitution)
-    assert result.text == log_dir
+    assert isinstance(result, LaunchLogDir)