Add 'custom_formats' argument to generated code

Previously `custom_formats` was assumed to be global, which works fine
for evaluation, but results in errors when generating code.

The approach used to fix this problem was to add a second argument to
the `validate` functions when custom formats are provided.
For execution, the function is wrapped with a `partial` that hides the
extra argument (and therefore avoids changes in the API or documentation).

Author: abravalheri

Diff for: fastjsonschema/__init__.py

@@ -75,6 +75,7 @@
 API
 ***
 """
+from functools import partial, update_wrapper
 
 from .draft04 import CodeGeneratorDraft04
 from .draft06 import CodeGeneratorDraft06
@@ -177,7 +178,10 @@ def compile(definition, handlers={}, formats={}, use_default=True):
     global_state = code_generator.global_state
     # Do not pass local state so it can recursively call itself.
     exec(code_generator.func_code, global_state)
-    return global_state[resolver.get_scope_name()]
+    func = global_state[resolver.get_scope_name()]
+    if formats:
+        return update_wrapper(partial(func, custom_formats=formats), func)
+    return func
 
 
 # pylint: disable=dangerous-default-value

Diff for: fastjsonschema/generator.py

@@ -32,6 +32,7 @@ class CodeGenerator:
     def __init__(self, definition, resolver=None):
         self._code = []
         self._compile_regexps = {}
+        self._custom_formats = {}
 
         # Any extra library should be here to be imported only once.
         # Lines are imports to be printed in the file and objects
@@ -136,7 +137,8 @@ def generate_validation_function(self, uri, name):
         self._validation_functions_done.add(uri)
         self.l('')
         with self._resolver.resolving(uri) as definition:
-            with self.l('def {}(data):', name):
+            args = "data, custom_formats={}" if self._custom_formats else "data"
+            with self.l('def {}({}):', name, args):
                 self.generate_func_code_block(definition, 'data', 'data', clear_variables=True)
                 self.l('return data')
 

Diff for: tests/test_compile_to_code.py

@@ -2,6 +2,7 @@
 import pytest
 import shutil
 
+from fastjsonschema import JsonSchemaValueException
 from fastjsonschema import compile_to_code, compile as compile_spec
 
 @pytest.yield_fixture(autouse=True)
@@ -84,3 +85,14 @@ def test_compile_complex_one_of_all_of():
             }
         ]
     })
+
+
+def test_compile_to_code_custom_format():
+    formats = {'identifier': str.isidentifier}
+    code = compile_to_code({'type': 'string', 'format': 'identifier'}, formats=formats)
+    with open('temp/schema_3.py', 'w') as f:
+        f.write(code)
+    from temp.schema_3 import validate
+    assert validate("identifier", formats) == "identifier"
+    with pytest.raises(JsonSchemaValueException):
+        validate("not-identifier", formats)