python expressions substitution include names of all parents for specified modules

launch/test/launch/frontend/test_substitutions.py

@@ -367,3 +367,13 @@ def test_execute_process_parse_cmd_line() -> None:
     cmd_subs = ExecuteProcess._parse_cmdline(cmd_text, parser)
     cmd_performed = expand_cmd_subs(cmd_subs)
     assert cmd_performed == ['that', 'this']
+
+
+def test_eval_subst_submodule():
+    # Case where a submodule is used
+    subst = parse_substitution(
+        r'$(eval "os.path.exists(\'/\')" "os")')
+    assert len(subst) == 1
+    expr = subst[0]
+    assert isinstance(expr, PythonExpression)
+    assert expr.perform(LaunchContext())

launch/test/launch/substitutions/test_python_expression.py

@@ -114,3 +114,26 @@ def test_python_substitution_two_modules():
     # Test the describe() method
     assert subst.describe() ==\
         "PythonExpr('math.isfinite(sys.getrefcount(str(\"hello world!\")))', ['sys', 'math'])"
+
+
+def test_python_substitution_submodule():
+    """Evaluation of submodules within a package."""
+    python_modules = ['launch']
+    lc = LaunchContext()
+    expr = (
+        'not launch.utilities.is_a_subclass('
+        '    launch.substitutions.PythonExpression, '
+        '    launch.substitutions.SubstitutionFailure'
+        ')'
+    )
+    subst = PythonExpression([expr], python_modules)
+    try:
+        result = subst.perform(lc)
+    except NameError:
+        pytest.fail('Failed to evaluate PythonExpression containing submodules.'
+                    'There may be a missing import.')
+    except SubstitutionFailure:
+        pytest.fail('Failed to evaluate PythonExpression containing submodules.')
+
+    # The expression should evaluate to True
+    assert result