simplify function, and make it so that aliases and hashes of the same

value return the same module, so the same code doesn't get imported
multiple times..

casimport/__init__.py

@@ -215,12 +215,15 @@ class CASFinder(MetaPathFinder, Loader):
 	def __exit__(self, exc_type, exc_value, traceback):
 		self.disconnect()
 
+	def load_aliases(self, data):
+		self._aliases.update(self._parsealiases(data))
+
 	def load_mod_aliases(self, name):
 		'''Load the aliases from the module with the passed in name.'''
 
 		aliases = importlib.resources.read_text(sys.modules[name],
 		    'cas_aliases.txt')
-		self._aliases.update(self._parsealiases(aliases))
+		self.load_aliases(aliases)
 
 	@staticmethod
 	def _makebasichashurl(url):
@@ -302,6 +305,9 @@ class CASFinder(MetaPathFinder, Loader):
 				else:
 					raise ValueError('unable to find base hash url for alias %s' % repr(arg))
 
+				# fix up the full name:
+				fullname = 'cas.v1_f_%s' % hashurl.path[1:]
+
 			ms = ModuleSpec(fullname, self, is_package=False,
 			    loader_state=(hashurl,))
 
@@ -532,39 +538,63 @@ class Test(unittest.TestCase):
 				],
 			})
 
+	def test_aliasmulti(self):
+		# setup the cache
+		cachedir = self.tempdir / 'cache'
+		cachedir.mkdir()
+
+		with CASFinder() as f, \
+		    tempattrset(sys.modules[__name__],
+		    'load_mod_aliases', f.load_mod_aliases):
+			f.register(FileDirCAS(cachedir))
+
+			# and that hello.py is in the cache
+			shutil.copy(self.fixtures / 'hello.py',
+			    cachedir)
+
+			# and that the aliases are loaded
+			with open(self.fixtures / 'randpkg' / 'cas_aliases.txt') as fp:
+				f.load_aliases(fp.read())
+
+			# that when we load the alias first
+			from cas.v1_a_hello import hello as hello_alias
+
+			# and then load the same module via hash
+			from cas.v1_f_330884aa2febb5e19fb7194ec6a69ed11dd3d77122f1a5175ee93e73cf0161c3 import hello as hello_hash
+
+			# they are the same
+			self.assertIs(hello_alias, hello_hash)
+
 	def test_aliasimports(self):
 		# setup the cache
-		temphome = self.tempdir / 'home'
-		temphome.mkdir()
-		cachedir = temphome / '.casimport' / 'cache'
-		cachedir.mkdir(parents=True)
+		cachedir = self.tempdir / 'cache'
+		cachedir.mkdir()
 
 		# add the test module's path
 		fixdir = str(self.fixtures)
 		sys.path.append(fixdir)
 
-		with tempset(os.environ, 'HOME', str(temphome)):
-			try:
-				with CASFinder() as f, \
-				    tempattrset(sys.modules[__name__],
-				    'load_mod_aliases', f.load_mod_aliases):
-					f.register(FileDirCAS(cachedir))
+		try:
+			with CASFinder() as f, \
+			    tempattrset(sys.modules[__name__],
+			    'load_mod_aliases', f.load_mod_aliases):
+				f.register(FileDirCAS(cachedir))
 
-					# and that hello.py is in the cache
-					shutil.copy(self.fixtures / 'hello.py',
-					    cachedir)
+				# and that hello.py is in the cache
+				shutil.copy(self.fixtures / 'hello.py',
+				    cachedir)
 
-					self.assertNotIn('randpkg', sys.modules)
+				self.assertNotIn('randpkg', sys.modules)
 
-					# that the import is successful
-					import randpkg
+				# that the import is successful
+				import randpkg
 
-					# and pulled in the method
-					self.assertTrue(hasattr(randpkg, 'hello'))
+				# and pulled in the method
+				self.assertTrue(hasattr(randpkg, 'hello'))
 
-					del sys.modules['randpkg']
-			finally:
-				sys.path.remove(fixdir)
+				del sys.modules['randpkg']
+		finally:
+			sys.path.remove(fixdir)
 
 	def test_aliasipfsimports(self):
 		# add the test module's path
@@ -679,6 +709,7 @@ class Test(unittest.TestCase):
 		with self.assertRaises(RuntimeError):
 			httpsldr.fetch_data(hashurl)
 
+	@unittest.skip('todo')
 	def test_overlappingaliases(self):
 		# make sure that an aliases file is consistent and does not
 		# override other urls.  That is that any hashes are
@@ -690,6 +721,7 @@ class Test(unittest.TestCase):
 		# this case, BOTH hashse have to be checked.
 		pass
 
+	@unittest.skip('todo')
 	def test_loaderpriority(self):
 		# XXX - write test to allow you to specify the priority of
 		# a loader, to ensure that cache stays at top.