adding available plugins function and test

glue/main.py

@@ -3,7 +3,7 @@
 from importlib import import_module
 
 from glue.logger import logger
-from glue._plugin_helpers import REQUIRED_PLUGINS, REQUIRED_PLUGINS_QT
+from glue._plugin_helpers import REQUIRED_PLUGINS
 
 
 _loaded_plugins = set()
@@ -50,8 +50,8 @@ def load_plugins(splash=None, require_qt_plugins=False, plugins_to_load=None):
 
     if plugins_to_load is None:
         plugins_to_load = [i.module for i in list(iter_plugin_entry_points())]
-        if require_qt_plugins:
-            plugins_to_require = [*REQUIRED_PLUGINS, *REQUIRED_PLUGINS_QT]
+        if plugins_to_load:
+            plugins_to_require = [*REQUIRED_PLUGINS]
         else:
             plugins_to_require = REQUIRED_PLUGINS
     else:
@@ -116,8 +116,18 @@ def load_plugins(splash=None, require_qt_plugins=False, plugins_to_load=None):
     load_settings()
 
 
-def list_plugins():
+def list_loaded_plugins():
     """
     Function to list all plugins that are currently loaded
     """
     return sorted(_loaded_plugins)
+
+
+def list_available_plugins():
+    """
+    Function to list all available plugins
+    """
+    from glue._plugin_helpers import iter_plugin_entry_points
+
+    plugins_load_list = [i.module for i in list(iter_plugin_entry_points())]
+    return plugins_load_list

glue/tests/test_main.py

@@ -1,7 +1,6 @@
 from unittest.mock import patch
 
-from glue.main import load_plugins
-from glue.main import list_plugins
+from glue.main import load_plugins,list_loaded_plugins, list_available_plugins
 
 
 def test_load_plugins(capsys):
@@ -20,6 +19,7 @@ def test_load_plugins(capsys):
             plugins.append(acall[0][0])
 
     assert len(plugins) == 5
+    assert 'glue.plugins.tools' in plugins
 
 
 def test_no_duplicate_loading(capsys):
@@ -39,11 +39,22 @@ def test_no_duplicate_loading(capsys):
             assert 'failed' in acall[0][0]
 
 
-def test_list_plugins():
+def test_list_loaded_plugins():
     """
     Regression test for retrieving the list of currently loaded plugins
     """
     load_plugins(require_qt_plugins=False)
-    plugins = list_plugins()
+    plugins = list_loaded_plugins()
     assert isinstance(plugins, list)
     assert len(plugins) == 5
+
+
+def test_list_available_plugins():
+    """
+    Regression test for retrieving the list of currently available plugins
+    """
+    available_plugins = list_available_plugins()
+    assert isinstance(available_plugins, list)
+    assert len(available_plugins) == 7
+    assert 'casa_formats_io.glue_factory' in available_plugins
+    assert 'glue.plugins.wcs_autolinking' in available_plugins