Use store argument for RefResolver as if it was mandatory

This is necessary to avoid problems with recompilation and caching of
schemas.

Author: abravalheri

fastjsonschema/__init__.py

@@ -213,7 +213,7 @@ def compile_to_code(definition, handlers={}, formats={}, use_default=True):
 
 
 def _factory(definition, handlers, formats={}, use_default=True):
-    resolver = RefResolver.from_schema(definition, handlers=handlers)
+    resolver = RefResolver.from_schema(definition, handlers=handlers, store={})
     code_generator = _get_code_generator_class(definition)(
         definition,
         resolver=resolver,

fastjsonschema/generator.py

@@ -54,7 +54,7 @@ def __init__(self, definition, resolver=None):
         self._validation_functions_done = set()
 
         if resolver is None:
-            resolver = RefResolver.from_schema(definition)
+            resolver = RefResolver.from_schema(definition, store={})
         self._resolver = resolver
 
         # add main function to `self._needed_validation_functions`

fastjsonschema/ref_resolver.py

@@ -77,12 +77,19 @@ class RefResolver:
     def __init__(self, base_uri, schema, store={}, cache=True, handlers={}):
         """
         `base_uri` is URI of the referring document from the `schema`.
+        `store` is an dictionary that will be used to cache the fetched schemas
+        (if `cache=True`).
+
+        Please notice that you can have caching problems when compiling schemas
+        with colliding `$ref`. To force overwriting use `cache=False` or
+        explicitly pass the `store` argument (with a brand new dictionary)
         """
         self.base_uri = base_uri
         self.resolution_scope = base_uri
         self.schema = schema
         self.store = store
         self.cache = cache
+        # ^-- Create a brand new cache if the 
         self.handlers = handlers
         self.walk(schema)