IPython/core/tests/test_extension.py

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')

def test_non_extension():
    em = get_ipython().extension_manager
    nt.assert_equal(em.load_extension('sys'), "no load function")