Extended syntax

README.md

@@ -9,9 +9,9 @@
 Gestalt
 =======
 
-Gestalt lets you use the [GraphQL](http://graphql.org/) schema language and a
-small set of directives to define an API with a PostgreSQL backend
-declaratively, *really quickly*, and with a *tiny* amount of code.
+Gestalt lets you use an extended version of the [GraphQL](http://graphql.org/)
+schema language to define an API with a PostgreSQL backend declaratively,
+*really quickly*, and with a *tiny* amount of code.
 
 [![Build Status](https://travis-ci.org/charlieschwabacher/gestalt.svg?branch=master)](https://travis-ci.org/charlieschwabacher/gestalt?branch=master)
 
@@ -106,21 +106,20 @@ tables.  Other objects and arrays they reference are stored in PostgreSQL as
 JSON, and relationships between nodes are specified with directives.
 
 
-Object relationships
---------------------
+Language Extensions
+-------------------
 Gestalt needs information about the relationships between objects to generate a
-database schema and efficient queries.  You provide this using the
-`@relationship` directive and a syntax inspired by
-[Neo4j](//github.com/neo4j/neo4j)'s Cypher query language.
+database schema and efficient queries.  You provide this using a syntax inspired
+by [Neo4j](//github.com/neo4j/neo4j)'s Cypher query language.
 
 ```GraphQL
 type User implements Node {
   name: String
-  posts: Post @relationship(path: "=AUTHORED=>")
+  posts: =AUTHORED=> Post
 }
 type Post implements Node {
   text: String
-  author: User @relationship(path: "<-AUTHORED-")
+  author: <-AUTHORED- User
 }
 ```
 
@@ -157,14 +156,14 @@ complex relationships between types:
 ```GraphQL
 type User implements Node {
   name: String
-  posts: Post @relationship(path: "=AUTHORED=>")
-  followedUsers: User @relationship(path: "=FOLLOWED=>")
-  followers: User @relationship(path: "<=FOLLOWED=")
-  feed: Post @relationship(path: "=FOLLOWED=>User=AUTHORED=>")
+  posts: =AUTHORED=> Post
+  followedUsers: =FOLLOWED=> User
+  followers: <=FOLLOWED= User
+  feed: =FOLLOWED=> User =AUTHORED=> Post
 }
 type Post implements Node {
   text: String
-  author: User @relationship(path: "<-AUTHORED-")
+  author: <-AUTHORED- User
 }
 ```
 
@@ -187,10 +186,10 @@ user' and does not.  Following these two rules will lead to a semantic database
 schema, and readable code in `schema.graphql`.
 
 
-Other directives
-----------------
-There are a few more directives used by Gestalt to provide extra information
-about how to create the database and GraphQL schemas.
+Directives
+----------
+There are a few directives used by Gestalt to provide extra information about
+how to create the database and GraphQL schemas.
 
 - `@hidden` is used to define fields that should become part of the database
   schema but not be exposed as part of the GraphQL schema.  It can be used for

packages/blogs-example/schema.graphql

@@ -13,16 +13,16 @@ type User implements Node {
   fullName: String @virtual
   profileImage(size: Int): String! @virtual
   following: Boolean! @virtual
-  followedUsers: User @relationship(path: "=FOLLOWED=>")
-  followers: User @relationship(path: "<=FOLLOWED=")
-  posts: Post @relationship(path: "=AUTHORED=>")
-  feed: Post @relationship(path: "=FOLLOWED=>User=AUTHORED=>")
+  followedUsers: =FOLLOWED=> User
+  followers: <=FOLLOWED= User
+  posts: =AUTHORED=> Post
+  feed: =FOLLOWED=> User =AUTHORED=> Post
 }
 
 type Post implements Node {
   id: ID!
   title: String! @index
   text: String!
   createdAt: Date!
-  author: User @relationship(path: "<-AUTHORED-")
+  author: <-AUTHORED- User
 }

packages/gestalt-cli/src/migrate.js

@@ -11,8 +11,8 @@ import {blue} from 'colors/safe';
 import snake from 'snake-case';
 import {graphql, parse} from 'graphql';
 import {introspectionQuery} from 'graphql/utilities';
-import {generateGraphQLSchemaWithoutResolution, databaseInfoFromAST} from
-  'gestalt-graphql';
+import {generateGraphQLSchemaWithoutResolution, databaseInfoFromAST,
+  translateSyntaxExtensions} from 'gestalt-graphql';
 import {generateDatabaseInterface, generateDatabaseSchemaMigration,
   readExistingDatabaseSchema} from 'gestalt-postgres';
 import {invariant} from 'gestalt-utils';
@@ -30,6 +30,7 @@ export default async function migrate() {
     );
 
     const schemaText = fs.readFileSync('schema.graphql', 'utf8');
+    const translatedText = translateSyntaxExtensions(schemaText);
     const localPackage = JSON.parse(fs.readFileSync('package.json', 'utf8'));
     const localVersion = localPackage.dependencies['gestalt-server'];
     const cliVersion = require('../package.json').version;
@@ -44,8 +45,8 @@ export default async function migrate() {
 
     console.log('migrating..');
 
-    await updateJSONSchema(localPackage, schemaText);
-    await updateDatabaseSchema(localPackage, schemaText);
+    await updateJSONSchema(localPackage, translatedText);
+    await updateDatabaseSchema(localPackage, translatedText);
 
   } catch (err) {
 

packages/gestalt-graphql/src/generateGraphQLSchema.js

@@ -7,6 +7,7 @@ import camel from 'camel-case';
 import {parse, buildASTSchema, concatAST, printSchema, GraphQLObjectType,
   getNamedType, GraphQLSchema} from 'graphql';
 import {mutationWithClientMutationId} from 'graphql-relay';
+import translateSyntaxExtensions from './translateSyntaxExtensions';
 import {insertConnectionTypes, removeHiddenNodes} from './ASTTransforms';
 import databaseInfoFromAST from './databaseInfoFromAST';
 import scalarTypeDefinitions from './scalarTypeDefinitions';
@@ -25,7 +26,8 @@ export default function generateGraphQLSchema(
   databaseInterfaceDefinitionFn: DatabaseInterfaceDefinitionFn,
   config?: GestaltServerConfig,
 ): {schema: GraphQLSchema, databaseInterface: DatabaseInterface} {
-  const ast = parse(schemaText);
+  const translatedText = translateSyntaxExtensions(schemaText);
+  const ast = parse(translatedText);
 
   // we take inventory of object definitions and relationships before the ast
   // is modified

packages/gestalt-graphql/src/index.js

@@ -1,3 +1,5 @@
 export {default, generateGraphQLSchemaWithoutResolution} from
   './generateGraphQLSchema';
 export {default as databaseInfoFromAST} from './databaseInfoFromAST';
+export {default as translateSyntaxExtensions} from
+  './translateSyntaxExtensions';

packages/gestalt-graphql/src/translateSyntaxExtensions.js

@@ -0,0 +1,31 @@
+// @flow
+
+// the regex below matches singular or plural arrows in either direction,
+// followed by typenames, repeating any number of times.
+// ie:
+// =FOLLOWED=>User=AUTHORED=>Post
+// or:
+// <-AUTHORED-User
+
+import {invariant} from 'gestalt-utils';
+
+const ARROW_MATCHER =
+  /:[ \t]*(?:(?:<([=-])[ \t]*[A-Z_]+[ \t]*\1|([=-])[ \t]*[A-Z_]+[ \t]*\2>)[ \t]*[A-Z][a-zA-Z0-9]*!?[ \t]*)+/g;
+
+export default function translateSyntaxExtensions(schemaText: string): string {
+  const translatedSchema = schemaText.replace(
+    ARROW_MATCHER,
+    (arrow: string): string => {
+      const normalArrow = arrow.replace(/[ \t:]/g, '');
+
+      const match = normalArrow.match(/[A-Z][a-zA-Z0-9]+!?$/);
+      invariant(match != null, 'error parsing schema');
+      const finalType = match[0];
+
+      const path = normalArrow.slice(0, normalArrow.length - finalType.length);
+
+      return `: ${finalType} @relationship(path: "${path}")`;
+    }
+  );
+  return translatedSchema;
+}

packages/gestalt-graphql/test/fixtures/schemaWithSyntaxExtensions.graphql

@@ -0,0 +1,36 @@
+type Session {
+  id: ID!
+  currentUser: User
+}
+
+type User implements Node {
+  id: ID!
+  email: String! @unique @hidden @index
+  passwordHash: String! @hidden
+  createdAt: Date!
+  firstName: String
+  lastName: String
+  fullName: String @virtual
+  followedUsers: =FOLLOWED=> User
+  followers: <=FOLLOWED= User
+  posts: =AUTHORED=> Post
+  comments: =AUTHORED=> Comment
+  feed: =FOLLOWED=> User =AUTHORED=> Post
+}
+
+type Post implements Node {
+  id: ID!
+  title: String! @index
+  text: String!
+  createdAt: Date!
+  author: <-AUTHORED- User!
+  comments: =INSPIRED=> Comment
+}
+
+type Comment implements Node {
+  id: ID!
+  text: String!
+  createdAt: Date!
+  author: <-AUTHORED- User
+  subject: <-INSPIRED- Post!
+}

packages/gestalt-graphql/test/translateSyntaxExtensionsText.js

@@ -0,0 +1,15 @@
+import assert from 'assert';
+import fs from 'fs';
+import translateSyntaxExtensions from '../src/translateSyntaxExtensions';
+
+const schema = fs.readFileSync(`${__dirname}/fixtures/schema.graphql`, 'utf8');
+const schemaWithSyntaxExtensions = fs.readFileSync(
+  `${__dirname}/fixtures/schemaWithSyntaxExtensions.graphql`,
+  'utf8'
+);
+
+describe('translateSyntaxExtensions', () => {
+  it('translates infix arrow syntax to @relationship directives', () => {
+    assert.equal(translateSyntaxExtensions(schemaWithSyntaxExtensions), schema);
+  });
+});

packages/gestalt-postgres/src/index.js

@@ -9,6 +9,7 @@ export {default as generateDatabaseSchemaMigration} from
   './generateDatabaseSchemaMigration';
 export {default as readExistingDatabaseSchema} from
   './readExistingDatabaseSchema';
+export {default as DB} from './DB';
 
 export default function gestaltPostgres(databaseAdapterConfig: {
   databaseURL: string