Add test for extension loading and unloading

IPython/core/tests/test_extension.py

@@ -0,0 +1,69 b''
+import os.path
+
+import nose.tools as nt
+
+import IPython.testing.tools as tt
+from IPython.utils.syspathcontext import prepended_to_syspath
+from IPython.utils.tempdir import TemporaryDirectory
+
+ext1_content = """
+def load_ipython_extension(ip):
+    print("Running ext1 load")
+
+def unload_ipython_extension(ip):
+    print("Running ext1 unload")
+"""
+
+ext2_content = """
+def load_ipython_extension(ip):
+    print("Running ext2 load")
+"""
+
+def test_extension_loading():
+    em = get_ipython().extension_manager
+    with TemporaryDirectory() as td:
+        ext1 = os.path.join(td, 'ext1.py')
+        with open(ext1, 'w') as f:
+            f.write(ext1_content)
+        
+        ext2 = os.path.join(td, 'ext2.py')
+        with open(ext2, 'w') as f:
+            f.write(ext2_content)
+        
+        with prepended_to_syspath(td):
+            assert 'ext1' not in em.loaded
+            assert 'ext2' not in em.loaded
+            
+            # Load extension
+            with tt.AssertPrints("Running ext1 load"):
+                assert em.load_extension('ext1') is None
+            assert 'ext1' in em.loaded
+            
+            # Should refuse to load it again
+            with tt.AssertNotPrints("Running ext1 load"):
+                assert em.load_extension('ext1') == 'already loaded'
+            
+            # Reload
+            with tt.AssertPrints("Running ext1 unload"):
+                with tt.AssertPrints("Running ext1 load", suppress=False):
+                    em.reload_extension('ext1')
+            
+            # Unload
+            with tt.AssertPrints("Running ext1 unload"):
+                assert em.unload_extension('ext1') is None
+            
+            # Can't unload again
+            with tt.AssertNotPrints("Running ext1 unload"):
+                assert em.unload_extension('ext1') == 'not loaded'
+            assert em.unload_extension('ext2') == 'not loaded'
+            
+            # Load extension 2
+            with tt.AssertPrints("Running ext2 load"):
+                assert em.load_extension('ext2') is None
+            
+            # Can't unload this
+            assert em.unload_extension('ext2') == 'no unload function'
+            
+            # But can reload it
+            with tt.AssertPrints("Running ext2 load"):
+                em.reload_extension('ext2')