Fix launch_testing output filtering (ros2#296)

* Fix launch_testing output filtering.

Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com>

* Add test case for launch_testing.tools.basic_output_filter

Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com>

* Replace os.linesep with '\n'

Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com>

* Deal with all possible line boundaries.

Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com>

launch_testing/launch_testing/tools/output.py

@@ -43,21 +43,19 @@ def basic_output_filter(
         filtered_prefixes = get_default_filtered_prefixes()
     if filtered_patterns is None:
         filtered_patterns = get_default_filtered_patterns()
-    filtered_patterns = map(re.compile, filtered_patterns)
+    filtered_patterns = list(map(re.compile, filtered_patterns))
 
     def _filter(output):
-        filtered_output = []
-        for line in output.splitlines():
+        filtered_output_lines = []
+        for line in output.splitlines(keepends=True):
             # Filter out stdout that comes from underlying DDS implementation
             # Note: we do not currently support matching filters across multiple stdout lines.
             if any(line.startswith(prefix) for prefix in filtered_prefixes):
                 continue
             if any(pattern.match(line) for pattern in filtered_patterns):
                 continue
-            filtered_output.append(line)
-        if output.endswith(os.linesep):
-            filtered_output.append(os.linesep)
-        return os.linesep.join(filtered_output)
+            filtered_output_lines.append(line)
+        return ''.join(filtered_output_lines)
     return _filter
 
 

launch_testing/test/launch_testing/test_tools.py

@@ -0,0 +1,52 @@
+# Copyright 2019 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.
+
+
+from launch_testing.tools import basic_output_filter
+
+
+def test_basic_output_filter():
+    filter_fn = basic_output_filter(
+        filtered_patterns=[r'.*\[listener\].*']
+    )
+
+    assert filter_fn('[listener] I heard: foo') == ''
+
+    assert filter_fn('[talker] I said: foo') == '[talker] I said: foo'
+
+    input_content = """\
+        [listener] I heard: foo
+        [listener] I heard: bar
+        [listener] I heard: foobar
+    """.replace('    ', '')
+    output_content = ''
+    assert filter_fn(input_content) == output_content
+
+    input_content = """\
+        [talker] I said: foo
+        [listener] I heard: bar
+        [listener] I heard: foobar
+    """.replace('    ', '')
+    output_content = """\
+        [talker] I said: foo
+    """.replace('    ', '')
+    assert filter_fn(input_content) == output_content
+
+    input_content = """\
+        [talker] I said: foo
+        [talker] I said: bar
+        [talker] I said: foobar
+    """.replace('    ', '')
+    output_content = input_content
+    assert filter_fn(input_content) == output_content