add a separate api testing file, #181

test/test_api.py

@@ -0,0 +1,23 @@
+import jedi
+from jedi import common
+
+
+def test_preload_modules():
+    def check_loaded(*modules):
+        # + 1 for builtin, +1 for None module (currently used)
+        assert len(new) == len(modules) + 2
+        for i in modules + ('__builtin__',):
+            assert [i in k for k in new.keys() if k is not None]
+
+    from jedi import cache
+    temp_cache, cache.parser_cache = cache.parser_cache, {}
+    new = cache.parser_cache
+    with common.ignored(KeyError): # performance of tests -> no reload
+        new['__builtin__'] = temp_cache['__builtin__']
+
+    jedi.preload_module('datetime')
+    check_loaded('datetime')
+    jedi.preload_module('json', 'token')
+    check_loaded('datetime', 'json', 'token')
+
+    cache.parser_cache = temp_cache