Improved GraphQL DSL 😊. Fixed #12

Author: syrusakbary

gql/dsl.py

@@ -5,9 +5,44 @@
 import six
 from graphql.language import ast
 from graphql.language.printer import print_ast
-from graphql.type import (GraphQLField, GraphQLFieldDefinition, GraphQLList,
+from graphql.type import (GraphQLField, GraphQLList,
                           GraphQLNonNull, GraphQLEnumType)
 
+from .utils import to_camel_case
+
+
+class DSLSchema(object):
+    def __init__(self, client):
+        self.client = client
+
+    @property
+    def schema(self):
+        return self.client.schema
+
+    def __getattr__(self, name):
+        type_def = self.schema.get_type(name)
+        return DSLType(type_def)
+
+
+class DSLType(object):
+    def __init__(self, type):
+        self.type = type
+
+    def __getattr__(self, name):
+        formatted_name, field_def = self.get_field(name)
+        return DSLField(formatted_name, field_def)
+
+    def get_field(self, name):
+        camel_cased_name = to_camel_case(name)
+
+        if name in self.type.fields:
+            return name, self.type.fields[name]
+
+        if camel_cased_name in self.type.fields:
+            return camel_cased_name, self.type.fields[camel_cased_name]
+
+        raise KeyError('Field {} doesnt exist in type {}.'.format(name, self.type.name))
+
 
 def selections(*fields):
     for _field in fields:
@@ -30,9 +65,9 @@ def get_ast_value(value):
 
 class DSLField(object):
 
-    def __init__(self, field):
+    def __init__(self, name, field):
         self.field = field
-        self.ast_field = ast.Field(name=ast.Name(value=field.name), arguments=[])
+        self.ast_field = ast.Field(name=ast.Name(value=name), arguments=[])
         self.selection_set = None
 
     def get(self, *fields):
@@ -41,21 +76,16 @@ def get(self, *fields):
         self.ast_field.selection_set.selections.extend(selections(*fields))
         return self
 
+    def __call__(self, *args, **kwargs):
+        return self.get(*args, **kwargs)
+
     def alias(self, alias):
         self.ast_field.alias = ast.Name(value=alias)
         return self
 
-    def get_field_args(self):
-        if isinstance(self.field, GraphQLFieldDefinition):
-            # The args will be an array
-            return {
-                arg.name: arg for arg in self.field.args
-            }
-        return self.field.args
-
     def args(self, **args):
         for name, value in args.items():
-            arg = self.get_field_args().get(name)
+            arg = self.field.args.get(name)
             arg_type_serializer = get_arg_serializer(arg.type)
             value = arg_type_serializer(value)
             self.ast_field.arguments.append(
@@ -75,7 +105,7 @@ def __str__(self):
 
 
 def field(field, **args):
-    if isinstance(field, (GraphQLField, GraphQLFieldDefinition)):
+    if isinstance(field, GraphQLField):
         return DSLField(field).args(**args)
     elif isinstance(field, DSLField):
         return field

gql/utils.py

@@ -0,0 +1,21 @@
+import re
+
+
+# From this response in Stackoverflow
+# http://stackoverflow.com/a/19053800/1072990
+def to_camel_case(snake_str):
+    components = snake_str.split('_')
+    # We capitalize the first letter of each component except the first one
+    # with the 'title' method and join them together.
+    return components[0] + "".join(x.title() if x else '_' for x in components[1:])
+
+
+# From this response in Stackoverflow
+# http://stackoverflow.com/a/1176023/1072990
+def to_snake_case(name):
+    s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', name)
+    return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()
+
+
+def to_const(string):
+    return re.sub('[\W|^]+', '_', string).upper()

tests/starwars/test_dsl.py

@@ -1,39 +1,52 @@
-from gql import dsl
+import pytest
+
+from gql import Client
+from gql.dsl import DSLSchema
 
 from .schema import characterInterface, humanType, queryType
 
 
 # We construct a Simple DSL objects for easy field referencing
 
-class Query(object):
-    hero = queryType.get_fields()['hero']
-    human = queryType.get_fields()['human']
+# class Query(object):
+#     hero = queryType.fields['hero']
+#     human = queryType.fields['human']
+
+
+# class Character(object):
+#     id = characterInterface.fields['id']
+#     name = characterInterface.fields['name']
+#     friends = characterInterface.fields['friends']
+#     appears_in = characterInterface.fields['appearsIn']
 
 
-class Character(object):
-    id = characterInterface.get_fields()['id']
-    name = characterInterface.get_fields()['name']
-    friends = characterInterface.get_fields()['friends']
-    appears_in = characterInterface.get_fields()['appearsIn']
+# class Human(object):
+#     name = humanType.fields['name']
 
 
-class Human(object):
-    name = humanType.get_fields()['name']
+from .schema import StarWarsSchema
 
 
-def test_hero_name_query():
+@pytest.fixture
+def ds():
+    client = Client(schema=StarWarsSchema)
+    ds = DSLSchema(client)
+    return ds
+
+
+def test_hero_name_query(ds):
     query = '''
 hero {
   name
 }
     '''.strip()
-    query_dsl = dsl.field(Query.hero).get(
-        Character.name
+    query_dsl = ds.Query.hero(
+        ds.Character.name
     )
     assert query == str(query_dsl)
 
 
-def test_hero_name_and_friends_query():
+def test_hero_name_and_friends_query(ds):
     query = '''
 hero {
   id
@@ -43,17 +56,17 @@ def test_hero_name_and_friends_query():
   }
 }
     '''.strip()
-    query_dsl = dsl.field(Query.hero).get(
-        Character.id,
-        Character.name,
-        dsl.field(Character.friends).get(
-            Character.name,
+    query_dsl = ds.Query.hero(
+        ds.Character.id,
+        ds.Character.name,
+        ds.Character.friends(
+            ds.Character.name,
         )
     )
     assert query == str(query_dsl)
 
 
-def test_nested_query():
+def test_nested_query(ds):
     query = '''
 hero {
   name
@@ -66,27 +79,27 @@ def test_nested_query():
   }
 }
     '''.strip()
-    query_dsl = dsl.field(Query.hero).get(
-        Character.name,
-        dsl.field(Character.friends).get(
-            Character.name,
-            Character.appears_in,
-            dsl.field(Character.friends).get(
-                Character.name
+    query_dsl = ds.Query.hero(
+        ds.Character.name,
+        ds.Character.friends(
+            ds.Character.name,
+            ds.Character.appears_in,
+            ds.Character.friends(
+                ds.Character.name
             )
         )
     )
     assert query == str(query_dsl)
 
 
-def test_fetch_luke_query():
+def test_fetch_luke_query(ds):
     query = '''
 human(id: "1000") {
   name
 }
     '''.strip()
-    query_dsl = dsl.field(Query.human, id="1000").get(
-        Human.name,
+    query_dsl = ds.Query.human.args(id="1000").get(
+        ds.Human.name,
     )
 
     assert query == str(query_dsl)
@@ -153,19 +166,14 @@ def test_fetch_luke_query():
 #     assert result.data == expected
 
 
-def test_fetch_luke_aliased():
+def test_fetch_luke_aliased(ds):
     query = '''
 luke: human(id: "1000") {
   name
 }
     '''.strip()
-    expected = {
-        'luke': {
-            'name': 'Luke Skywalker',
-        }
-    }
-    query_dsl = dsl.field(Query.human, id=1000).alias('luke').get(
-        Character.name,
+    query_dsl = ds.Query.human.args(id=1000).alias('luke').get(
+        ds.Character.name,
     )
     assert query == str(query_dsl)