Print warning when get_package_share_directory() does not exist (Fix #74

) (#77)

* Fix #74

Signed-off-by: David V. Lu <davidvlu@gmail.com>

* Fix tests, change variable name, add documentation

Signed-off-by: David V. Lu <davidvlu@gmail.com>

ament_index_python/ament_index_python/packages.py

@@ -15,6 +15,7 @@
 import os
 import pathlib
 import re
+import warnings
 
 from .resources import get_resource
 from .resources import get_resources
@@ -61,7 +62,7 @@ def get_package_prefix(package_name):
     return package_prefix
 
 
-def get_package_share_directory(package_name):
+def get_package_share_directory(package_name, print_warning=True):
     """
     Return the share directory of the given package.
 
@@ -71,14 +72,18 @@ def get_package_share_directory(package_name):
     the package's share directory.
 
     :param str package_name: name of the package to locate
+    :param bool print_warning: if true, print a warning if the directory does not exist
     :returns: share directory of the package
     :raises: :exc:`PackageNotFoundError` if the package is not found
     :raises: :exc:`ValueError` if the package name is invalid
     """
-    return os.path.join(get_package_prefix(package_name), 'share', package_name)
+    path = os.path.join(get_package_prefix(package_name), 'share', package_name)
+    if print_warning and not os.path.exists(path):
+        warnings.warn(f'Share directory for {package_name} ({path}) does not exist.', stacklevel=2)
+    return path
 
 
-def get_package_share_path(package_name):
+def get_package_share_path(package_name, print_warning=True):
     """
     Return the share directory of the given package as a pathlib.Path.
 
@@ -89,7 +94,11 @@ def get_package_share_path(package_name):
     `get_package_share_path('foo') / 'urdf/robot.urdf'`
 
     :param str package_name: name of the package to locate
+    :param bool print_warning: if true, print a warning if the path does not exist
     :returns: share directory of the package as a pathlib.Path
     :raises: :exc:`PackageNotFoundError` if the package is not found
     """
-    return pathlib.Path(get_package_share_directory(package_name))
+    path = pathlib.Path(get_package_share_directory(package_name, print_warning=False))
+    if print_warning and not path.exists():
+        warnings.warn(f'Share path for {package_name} ({path}) does not exist.', stacklevel=2)
+    return path

ament_index_python/test/test_ament_index_python.py

@@ -200,7 +200,7 @@ def get_package_prefix_basename(package_name):
             get_package_prefix(name)
 
     with pytest.raises(ValueError):
-        # An absolue path is not a valid package name
+        # An absolute path is not a valid package name
         extant_absolute_path = os.path.abspath(__file__)
         get_package_prefix(extant_absolute_path)
 
@@ -228,6 +228,12 @@ def get_package_share_directory_test(package_name, expect_prefix):
     with pytest.raises(ValueError):
         get_package_share_directory('/invalid/package/name')
 
+    with pytest.warns(UserWarning):
+        # Package exists, but should print warning because there is no share dir
+        get_package_share_directory('trogdor')
+
+    get_package_share_directory('trogdor', print_warning=False)
+
 
 def test_get_package_share_path():
     set_ament_prefix_path(['prefix1', 'prefix2'])
@@ -247,6 +253,12 @@ def get_package_share_path_test(package_name, expect_prefix):
     with pytest.raises(PackageNotFoundError):
         get_package_share_path('does_not_exist')
 
+    with pytest.warns(UserWarning):
+        # Package exists, but should print warning because there is no share dir
+        get_package_share_path('trogdor')
+
+    get_package_share_path('trogdor', print_warning=False)
+
 
 def test_get_resource_types():
     set_ament_prefix_path([])
@@ -299,6 +311,7 @@ def test_main_tool(capsys):
         f"bar\t{base_path / 'prefix1'}",
         f"baz\t{base_path / 'prefix2'}",
         f"foo\t{base_path / 'prefix1'}",
+        f"trogdor\t{base_path / 'prefix1'}",
         ''
     ])
     assert captured.out == expected_result