Added reraise method to GraphQLError

.travis.yml

@@ -26,7 +26,6 @@ install:
 - pip install pytest==2.9.2
 - pip install -e .
 script:
-- flake8
 - py.test --cov=graphql graphql tests
 after_success:
 - coveralls
@@ -36,8 +35,10 @@ matrix:
     after_install:
     - pip install pytest-asyncio
     script:
-    - flake8
     - py.test --cov=graphql graphql tests tests_py35
+  - python: '2.7'
+    script:
+    - flake8
 deploy:
   provider: pypi
   user: syrusakbary

graphql/error/base.py

@@ -1,3 +1,4 @@
+import six
 from ..language.location import get_location
 
 
@@ -29,6 +30,12 @@ def positions(self):
             if any(node_positions):
                 return node_positions
 
+    def reraise(self):
+        if self.stack:
+            six.reraise(type(self), self, self.stack)
+        else:
+            raise self
+
     @property
     def locations(self):
         source = self.source

graphql/error/tests/test_base.py

@@ -0,0 +1,50 @@
+import pytest
+import traceback
+
+from graphql.execution import execute
+from graphql.language.parser import parse
+from graphql.type import (GraphQLField, GraphQLObjectType, GraphQLSchema,
+                          GraphQLString)
+
+
+def test_raise():
+    ast = parse('query Example { a }')
+
+    def resolver(context, *_):
+        raise Exception('Failed')
+
+    Type = GraphQLObjectType('Type', {
+        'a': GraphQLField(GraphQLString, resolver=resolver),
+    })
+
+    result = execute(GraphQLSchema(Type), ast)
+    assert str(result.errors[0]) == 'Failed'
+
+
+def test_reraise():
+    ast = parse('query Example { a }')
+
+    def resolver(context, *_):
+        raise Exception('Failed')
+
+    Type = GraphQLObjectType('Type', {
+        'a': GraphQLField(GraphQLString, resolver=resolver),
+    })
+
+    result = execute(GraphQLSchema(Type), ast)
+    with pytest.raises(Exception) as exc_info:
+        result.errors[0].reraise()
+
+    extracted = traceback.extract_tb(exc_info.tb)
+    formatted_tb = [row[2:] for row in extracted]
+    if formatted_tb[2][0] == 'reraise':
+        formatted_tb[2:] = formatted_tb[3:]
+
+    assert formatted_tb == [
+        ('test_reraise', 'result.errors[0].reraise()'),
+        ('reraise', 'six.reraise(type(self), self, self.stack)'),
+        # ('reraise', 'raise value.with_traceback(tb)'),
+        ('resolve_or_error', 'return executor.execute(resolve_fn, source, args, context, info)'),
+        ('execute', 'return fn(*args, **kwargs)'), ('resolver', "raise Exception('Failed')")
+    ]
+    assert str(exc_info.value) == 'Failed'

graphql/language/lexer.py

@@ -183,6 +183,7 @@ def read_token(source, from_position):
         source, position,
         u'Unexpected character {}.'.format(print_char_code(code)))
 
+
 ignored_whitespace_characters = frozenset([
     # BOM
     0xFEFF,

graphql/type/directives.py

@@ -68,6 +68,7 @@ def __init__(self, name, description=None, args=None, locations=None):
                     _arg.type)
         self.args = args or OrderedDict()
 
+
 """Used to conditionally include fields or fragments."""
 GraphQLIncludeDirective = GraphQLDirective(
     name='include',