Allow with_plugins() to accept a string

.travis.yml

@@ -10,6 +10,8 @@ python:
   - 3.5
   - 3.6
   - 3.7
+  - 3.8
+  - 3.9
 
 env:
   matrix:

README.rst

@@ -36,6 +36,24 @@ The only requirement is decorating ``click.group()`` with ``click_plugins.with_p
 which handles attaching external commands and groups.  In this case the core CLI developer
 registers CLI plugins from ``core_package.cli_plugins``.
 
+.. code-block:: python
+
+    import click
+    from click_plugins import with_plugins
+
+
+    @with_plugins('core_package.cli_plugins')
+    @click.group()
+    def cli():
+        """Commandline interface for yourpackage."""
+
+    @cli.command()
+    def subcommand():
+        """Subcommand that does something."""
+
+Alternatively, an iterable producing one ``pkg_resources.EntryPoint()`` per
+interation (like ``pkg_resources.iter_entry_points()``) can be used.
+
 .. code-block:: python
 
     from pkg_resources import iter_entry_points

click_plugins/__init__.py

@@ -3,13 +3,11 @@
 entry-points.
 
 
-    from pkg_resources import iter_entry_points
-
     import click
     from click_plugins import with_plugins
 
 
-    @with_plugins(iter_entry_points('entry_point.name'))
+    @with_plugins('entry_point.name')
     @click.group()
     def cli():
         '''Commandline interface for something.'''

click_plugins/core.py

@@ -8,6 +8,7 @@
 import os
 import sys
 import traceback
+from pkg_resources import iter_entry_points
 
 
 def with_plugins(plugins):
@@ -18,8 +19,9 @@ def with_plugins(plugins):
 
     Parameters
     ----------
-    plugins : iter
-        An iterable producing one `pkg_resources.EntryPoint()` per iteration.
+    plugins : str | iter
+        An entry point group name.
+        Alternatively an iterable producing one `pkg_resources.EntryPoint()` per iteration.
     attrs : **kwargs, optional
         Additional keyword arguments for instantiating `click.Group()`.
 
@@ -32,7 +34,11 @@ def decorator(group):
         if not isinstance(group, click.Group):
             raise TypeError("Plugins can only be attached to an instance of click.Group()")
 
-        for entry_point in plugins or ():
+        entry_points = plugins
+        if type(plugins) is str:
+            entry_points = iter_entry_points(plugins)
+
+        for entry_point in entry_points or ():
             try:
                 group.add_command(entry_point.load())
             except Exception:

example/PrintIt/printit/cli.py

@@ -3,13 +3,11 @@
 """
 
 
-from pkg_resources import iter_entry_points
-
 import click
 from click_plugins import with_plugins
 
 
-@with_plugins(iter_entry_points('printit.plugins'))
+@with_plugins('printit.plugins')
 @click.group()
 def cli():
 

tests/test_plugins.py

@@ -67,6 +67,13 @@ def broken_cli():
     """Broken CLI group."""
     pass
 
+# Passing the group name instead of the entry points iterator
+@with_plugins('_test_click_plugins.test_plugins')
+@click.group()
+def good_cli_by_name():
+    """Good CLI group referenced by name."""
+    pass
+
 
 def test_registered():
     # Make sure the plugins are properly registered.  If this test fails it
@@ -75,13 +82,14 @@ def test_registered():
     assert len([ep for ep in iter_entry_points('_test_click_plugins.broken_plugins')]) > 1
 
 
-def test_register_and_run(runner):
+@pytest.mark.parametrize("cli", [good_cli, good_cli_by_name])
+def test_register_and_run(runner, cli):
 
-    result = runner.invoke(good_cli)
+    result = runner.invoke(cli)
     assert result.exit_code == 0
 
     for ep in iter_entry_points('_test_click_plugins.test_plugins'):
-        cmd_result = runner.invoke(good_cli, [ep.name, 'something'])
+        cmd_result = runner.invoke(cli, [ep.name, 'something'])
         assert cmd_result.exit_code == 0
         assert cmd_result.output.strip() == 'passed'