support selecting steps by package name for strun

src/stpipe/cli/strun.py

@@ -1,6 +1,6 @@
 import sys
 
-from stpipe import Step
+from stpipe import cmdline
 from stpipe.cli.main import _print_versions
 from stpipe.exceptions import StpipeExitException
 
@@ -21,7 +21,7 @@ def main():
         sys.exit(0)
 
     try:
-        Step.from_cmdline(sys.argv[1:])
+        cmdline.step_from_cmdline(sys.argv[1:])
     except StpipeExitException as e:
         sys.exit(e.exit_status)
     except Exception:

src/stpipe/entry_points.py

@@ -1,7 +1,7 @@
 import warnings
 from collections import namedtuple
 
-from importlib_metadata import entry_points
+import importlib_metadata
 
 STEPS_GROUP = "stpipe.steps"
 
@@ -26,7 +26,7 @@ class alias, and the third is a bool indicating whether the class is to be
     """
     steps = []
 
-    for entry_point in entry_points(group=STEPS_GROUP):
+    for entry_point in importlib_metadata.entry_points(group=STEPS_GROUP):
         package_name = entry_point.dist.name
         package_version = entry_point.dist.version
         package_steps = []

src/stpipe/utilities.py

@@ -19,13 +19,24 @@ def resolve_step_class_alias(name):
     Parameters
     ----------
     name : str
+        If name contains "::" only the package with
+        a name matching the characters before "::"
+        will be searched for the matching step.
 
     Returns
     -------
     str
     """
+    # check if the name contains a package name
+    if "::" in name:
+        scope, class_name = name.split("::", maxsplit=1)
+    else:
+        scope, class_name = None, name
+
     for info in entry_points.get_steps():
-        if info.class_alias is not None and name == info.class_alias:
+        if scope and info.package_name != scope:
+            continue
+        if info.class_alias is not None and class_name == info.class_alias:
             return info.class_name
 
     return name

tests/test_utilities.py

@@ -1,7 +1,7 @@
 import pytest
 
 from stpipe import Step
-from stpipe.utilities import import_class, import_func
+from stpipe.utilities import import_class, import_func, resolve_step_class_alias
 
 
 def what_is_your_quest():
@@ -13,6 +13,8 @@ class HovercraftFullOfEels:
 
 
 class Foo(Step):
+    class_alias = "foo_step"
+
     def process(self, input_data):
         pass
 
@@ -52,3 +54,41 @@ def test_import_class_no_module():
 def test_import_func_no_module():
     with pytest.raises(ImportError):
         import_func("foo")
+
+
+@pytest.mark.parametrize(
+    "name, resolve",
+    (
+        ("foo_step", True),
+        ("stpipe::foo_step", True),
+        ("some_other_package::foo_step", False),
+    ),
+)
+def test_class_alias_lookup(name, resolve, monkeypatch):
+    # as the test class above isn't registered via an entry point
+    # we mock the entry points here
+    class FakeDist:
+        name = "stpipe"
+        version = "dev"
+
+    class FakeEntryPoint:
+        dist = FakeDist()
+
+        def load(self):
+            def loader():
+                return [("Foo", "foo_step", False)]
+
+            return loader
+
+    def fake_entrypoints(group=None):
+        return [FakeEntryPoint()]
+
+    import importlib_metadata
+
+    monkeypatch.setattr(importlib_metadata, "entry_points", fake_entrypoints)
+
+    resolved_name = resolve_step_class_alias(name)
+    if resolve:
+        assert resolved_name == Foo.__name__
+    else:
+        assert resolved_name == name