Enable users to load schemas from GraphQL files.

Implemented in response to graphql-python/graphql-core#137.

Author: Sairam Krishnan

graphql/__init__.py

@@ -89,6 +89,7 @@
 # Parse and operate on GraphQL language source files.
 from .language.base import (  # no import order
     Source,
+    FileSource,
     get_location,
     # Parse
     parse,
@@ -223,6 +224,7 @@
     "BREAK",
     "ParallelVisitor",
     "Source",
+    "FileSource",
     "TypeInfoVisitor",
     "get_location",
     "parse",

graphql/language/ast.py

@@ -1079,6 +1079,7 @@ def __repr__(self):
             "name={self.name!r}"
             ", arguments={self.arguments!r}"
             ", type={self.type!r}"
+            ", directives={self.directives!r}"
             ")"
         ).format(self=self)
 

graphql/language/base.py

@@ -2,7 +2,7 @@
 from .location import get_location
 from .parser import parse, parse_value
 from .printer import print_ast
-from .source import Source
+from .source import FileSource, Source
 from .visitor import BREAK, ParallelVisitor, TypeInfoVisitor, visit
 
 __all__ = [
@@ -12,6 +12,7 @@
     "parse_value",
     "print_ast",
     "Source",
+    "FileSource",
     "BREAK",
     "ParallelVisitor",
     "TypeInfoVisitor",

graphql/language/source.py

@@ -1,5 +1,6 @@
-__all__ = ["Source"]
+import os
 
+__all__ = ["Source", "FileSource"]
 
 class Source(object):
     __slots__ = "body", "name"
@@ -15,3 +16,45 @@ def __eq__(self, other):
             and self.body == other.body
             and self.name == other.name
         )
+
+class FileSource(Source):
+    __slots__ = "body", "name"
+
+    def __init__(self, *args, **kwargs):
+        """Create a Source using the specified GraphQL files' contents."""
+        name = kwargs.get("name", "GraphQL")
+
+        # From the specified list of paths, first identify all files. Then, load
+        # their contents into a single, newline delimited string.
+        file_contents = []
+        file_paths = self.__get_file_paths__(args)
+        for fp in file_paths:
+            with open(fp) as f:
+                file_contents.append(f.read())
+        body = '\n'.join(file_contents)
+
+        super(FileSource, self).__init__(body, name)
+
+    def __get_file_paths__(self, paths):
+        """Get the paths to all files in the given list of paths. This means
+        filtering out invalid paths and recursively walking a given directory
+        path to gather the paths of all files that it contains."""
+        all_file_paths = []
+
+        # Filter out invalid paths.
+        valid_paths = [p for p in paths if os.path.exists(p)]
+
+        # Add all paths pointing to a file to all_file_paths.
+        all_file_paths += [p for p in valid_paths if os.path.isfile(p)]
+
+        # For each path referring to a directory, walk that directory's structure
+        # recursively, and add its constituent files' paths to all_file_paths.
+        all_file_paths += [
+            os.path.join(dir_name, file_name)
+            for p in valid_paths
+            if os.path.isdir(p)
+            for dir_name, _, files_in_dir in os.walk(p)
+            for file_name in files_in_dir
+        ]
+
+        return all_file_paths

graphql/language/tests/test_schema_parser.py

@@ -1,6 +1,6 @@
 from pytest import raises
 
-from graphql import Source, parse
+from graphql import FileSource, Source, parse
 from graphql.error import GraphQLSyntaxError
 from graphql.language import ast
 from graphql.language.parser import Loc
@@ -567,6 +567,132 @@ def test_parses_simple_input_object():
     assert doc == expected
 
 
+def test_parses_schema_files():
+    doc = parse(FileSource("tests/graphql_schemas"))
+    expected = ast.Document(
+        definitions=[
+            ast.ObjectTypeDefinition(
+                name=ast.Name(value="Query"),
+                interfaces=[],
+                fields=[
+                    ast.FieldDefinition(
+                        name=ast.Name(value="person"),
+                        arguments=[
+                            ast.InputValueDefinition(
+                                name=ast.Name(value="name"),
+                                type=ast.NonNullType(
+                                    type=ast.NamedType(name=ast.Name(value="ID"))
+                                ),
+                                default_value=None,
+                                directives=[]
+                            )
+                        ],
+                        type=ast.NamedType(name=ast.Name(value="Person")),
+                        directives=[]
+                    ),
+                    ast.FieldDefinition(
+                        name=ast.Name(value="skill"),
+                        arguments=[
+                            ast.InputValueDefinition(
+                                name=ast.Name(value="name"),
+                                type=ast.NonNullType(
+                                    type=ast.NamedType(name=ast.Name(value="ID"))
+                                ),
+                                default_value=None,
+                                directives=[]
+                            )
+                        ],
+                        type=ast.NamedType(name=ast.Name(value="Skill")),
+                        directives=[]
+                    )
+                ],
+                directives=[]
+            ),
+            ast.SchemaDefinition(
+                operation_types=[
+                    ast.OperationTypeDefinition(
+                        operation="query",
+                        type=ast.NamedType(name=ast.Name(value="Query"))
+                    )
+                ],
+                directives=[]
+            ),
+            ast.ObjectTypeDefinition(
+                name=ast.Name(value="Person"),
+                interfaces=[],
+                fields=[
+                    ast.FieldDefinition(
+                        name=ast.Name(value="name"),
+                        arguments=[],
+                        type=ast.NonNullType(
+                            type=ast.NamedType(name=ast.Name(value="ID"))
+                        ),
+                        directives=[]
+                    ),
+                    ast.FieldDefinition(
+                        name=ast.Name(value="age"),
+                        arguments=[],
+                        type=ast.NamedType(name=ast.Name(value="Int")),
+                        directives=[]
+                    )
+                ],
+                directives=[]
+            ),
+            ast.ObjectTypeDefinition(
+                name=ast.Name(value="Skill"),
+                interfaces=[],
+                fields=[
+                    ast.FieldDefinition(
+                        name=ast.Name(value="name"),
+                        arguments=[],
+                        type=ast.NonNullType(
+                            type=ast.NamedType(name=ast.Name(value="ID"))
+                        ),
+                        directives=[]
+                    ),
+                    ast.FieldDefinition(
+                        name=ast.Name(value="level"),
+                        arguments=[],
+                        type=ast.NamedType(name=ast.Name(value="Int")),
+                        directives=[]
+                    ),
+                    ast.FieldDefinition(
+                        name=ast.Name(value="possessors"),
+                        arguments=[],
+                        type=ast.ListType(
+                            type=ast.NonNullType(
+                                type=ast.NamedType(name=ast.Name(value="Person"))
+                            )
+                        ),
+                        directives=[]
+                    )
+                ],
+                directives=[]
+            ),
+            ast.TypeExtensionDefinition(
+                definition=ast.ObjectTypeDefinition(
+                    name=ast.Name(value="Person"),
+                    interfaces=[],
+                    fields=[
+                        ast.FieldDefinition(
+                            name=ast.Name(value="skills"),
+                            arguments=[],
+                            type=ast.ListType(
+                                type=ast.NonNullType(
+                                    type=ast.NamedType(name=ast.Name(value="Skill"))
+                                )
+                            ),
+                            directives=[]
+                        )
+                    ],
+                    directives=[]
+                )
+            )
+        ]
+    )
+    assert doc == expected
+
+
 def test_parsing_simple_input_object_with_args_should_fail():
     # type: () -> None
     body = """

tests/graphql_schemas/models/Person.graphql

@@ -0,0 +1,4 @@
+type Person {
+    name: ID!
+    age: Int
+}

tests/graphql_schemas/models/Skill.graphql

@@ -0,0 +1,9 @@
+type Skill {
+    name: ID!
+    level: Int
+    possessors: [Person!]
+}
+
+extend type Person {
+    skills: [Skill!]
+}

tests/graphql_schemas/schema.graphql

@@ -0,0 +1,8 @@
+type Query {
+    person(name: ID!): Person
+    skill(name: ID!): Skill
+}
+
+schema {
+    query: Query
+}