fix: raise when detecting multiple entry points

aiida/plugins/entry_point.py

@@ -282,7 +282,9 @@ def get_entry_point(group: str, name: str) -> EntryPoint:
     found = eps().select(group=group, name=name)
     if name not in found.names:
         raise MissingEntryPointError(f"Entry point '{name}' not found in group '{group}'")
-    if len(found.names) > 1:
+    # If multiple entry points are found and they have different values we raise, otherwise if they all
+    # correspond to the same value, we simply return one of them
+    if len(found) > 1 and len(set(ep.value for ep in found)) != 1:
         raise MultipleEntryPointError(f"Multiple entry points '{name}' found in group '{group}': {found}")
     return found[name]
 

tests/plugins/test_entry_point.py

@@ -7,11 +7,15 @@
 # For further information on the license, see the LICENSE.txt file        #
 # For further information please visit http://www.aiida.net               #
 ###########################################################################
+# pylint: disable=redefined-outer-name
 """Tests for the :mod:`~aiida.plugins.entry_point` module."""
 import pytest
 
+from aiida.common.exceptions import MissingEntryPointError, MultipleEntryPointError
 from aiida.common.warnings import AiidaDeprecationWarning
-from aiida.plugins.entry_point import get_entry_point, validate_registered_entry_points
+from aiida.plugins import entry_point
+from aiida.plugins.entry_point import EntryPoint as EP
+from aiida.plugins.entry_point import EntryPoints, get_entry_point, validate_registered_entry_points
 
 
 def test_validate_registered_entry_points():
@@ -43,3 +47,51 @@ def test_get_entry_point_deprecated(group, name):
 
     with pytest.warns(AiidaDeprecationWarning, match=warning):
         get_entry_point(group, name)
+
+
+@pytest.fixture
+def eps(request):
+    """Mocked version of :func:`aiida.plugins.entry_point.eps`.
+
+    The mocked function returns a dummy class whose ``select`` method returns a fixed list of entry points that are
+    passed in via the ``request`` parameter with which ``pytest`` invokes the fixture.
+    """
+
+    class MockEntryPoints:
+
+        @staticmethod
+        def select(group, name):  # pylint: disable=unused-argument
+            return EntryPoints(request.param)
+
+    return MockEntryPoints
+
+
+@pytest.mark.parametrize(
+    'eps, name, exception', (
+        ((EP(name='ep', group='gr', value='x'),), None, None),
+        ((EP(name='ep', group='gr', value='x'),), 'non-existing', MissingEntryPointError),
+        ((EP(name='ep', group='gr', value='x'), EP(name='ep', group='gr', value='y')), None, MultipleEntryPointError),
+        ((EP(name='ep', group='gr', value='x'), EP(name='ep', group='gr', value='x')), None, None),
+    ),
+    indirect=['eps']
+)
+def test_get_entry_point(eps, name, exception, monkeypatch):
+    """Test the ``get_entry_point`` method.
+
+    Test four different cases:
+
+     * Requested entry point exists and no duplicates -> no exception
+     * Requested entry points does not exist -> MissingEntryPointError
+     * Requested entry point has two matches by name but hits have different values -> MultipleEntryPointError
+     * Requested entry point has two matches by name but hits have same values -> no exception
+
+    """
+    monkeypatch.setattr(entry_point, 'eps', eps)
+
+    name = name or 'ep'  # Try to load the entry point with name ``ep`` unless the fixture provides one
+
+    if exception:
+        with pytest.raises(exception):
+            get_entry_point(group='gr', name=name)
+    else:
+        get_entry_point(group='gr', name=name)