Handle zero-width string parameters. (ros2#72)

* Handle zero-width string parameters. Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com> * Restore yaml.safe_load usage. Signed-off-by: Michel Hidalgo <michel@ekumenlabs.com>
esteve · Sep 23, 2019 · b04713d · b04713d
1 parent d25e2b3
commit b04713d
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Showing 4 changed files with 10 additions and 1 deletion.
diff --git a/launch_ros/launch_ros/utilities/evaluate_parameters.py b/launch_ros/launch_ros/utilities/evaluate_parameters.py
@@ -68,6 +68,8 @@ def check_sequence_type_is_allowed(sequence):
                 # Value is a list of substitutions, so perform them to make a string
                 evaluated_value = perform_substitutions(context, list(value))
                 yaml_evaluated_value = yaml.safe_load(evaluated_value)
+                if yaml_evaluated_value is None:
+                    yaml_evaluated_value = ''
                 if type(yaml_evaluated_value) in (bool, int, float, str, bytes):
                     evaluated_value = yaml_evaluated_value
                 elif isinstance(yaml_evaluated_value, Sequence):

diff --git a/test_launch_ros/test/test_launch_ros/actions/example_parameters.yaml b/test_launch_ros/test/test_launch_ros/actions/example_parameters.yaml
@@ -3,6 +3,7 @@
         ros__parameters:
             some_int: 42
             a_string: "Hello world"
+            no_string: ""
             some_list:
                 sub_list:
                     some_integers: [1, 2, 3, 4]

diff --git a/test_launch_ros/test/test_launch_ros/actions/test_node.py b/test_launch_ros/test/test_launch_ros/actions/test_node.py
@@ -151,7 +151,8 @@ def test_launch_node_with_parameter_dict(self):
                     'param_group2': {
                         (EnvironmentVariable('PARAM2'), '_values'): ['param2_value'],
                     }
-                }
+                },
+                'param3': ''
             }],
         )
         self._assert_launch_no_errors([node_action])
@@ -166,6 +167,7 @@ def test_launch_node_with_parameter_dict(self):
                     'ros__parameters': {
                         'param1': 'param1_value',
                         'param2': 'param2_value',
+                        'param3': '',
                         'param_group1.list_params': (1.2, 3.4),
                         'param_group1.param_group2.param2_values': ('param2_value',),
                     }

diff --git a/test_launch_ros/test/test_launch_ros/frontend/test_node_frontend.py b/test_launch_ros/test/test_launch_ros/frontend/test_node_frontend.py
@@ -46,6 +46,7 @@
                 <param name="param9" value="\'2\', \'5\', \'8\'" value-sep=", "/>
                 <param name="param10" value="''asd'', ''bsd'', ''csd''" value-sep=", "/>
                 <param name="param11" value="'\asd', '\bsd', '\csd'" value-sep=", "/>
+                <param name="param12" value=""/>
             </param>
             <param from="{}"/>
             <env name="var" value="1"/>
@@ -96,6 +97,8 @@
                         value: ["'asd'", "'bsd'", "'csd'"]
                     -   name: param11
                         value: ['\asd', '\bsd', '\csd']
+                    -   name: param12
+                        value: ''
                 -   from: {}
             env:
                 -   name: var
@@ -141,3 +144,4 @@ def test_node_frontend(file):
     assert param_dict['param_group1.param9'] == ("'2'", "'5'", "'8'")
     assert param_dict['param_group1.param10'] == ("'asd'", "'bsd'", "'csd'")
     assert param_dict['param_group1.param11'] == ('asd', 'bsd', 'csd')
+    assert param_dict['param_group1.param12'] == ''