feat(functionality to extend types): added createBuild().extendType(type: string, config: TypeConfig

fix #111

Author: lordnox

src/bugs/111-need-to-be-able-to-extend-type.spec.ts

@@ -0,0 +1,40 @@
+import { graphql } from 'graphql'
+import { createSchemaBuilder } from '..'
+
+it('should not at inherit to interface definitions', async () => {
+  const builder = createSchemaBuilder()
+
+  const model = builder.model('Model', {
+    findOne: async () => ({
+      id: '1234567890',
+      created_at: new Date(),
+      updated_at: new Date(),
+      deleted_at: new Date(),
+    }),
+  })
+  model.attr('someInt', 'Int')
+  model.resolve(() => ({
+    someInt: () => 123,
+  }))
+
+  const build = builder.createBuild()
+  build.extendType('Model', {
+    fields: {
+      someStr: 'String!',
+    },
+    resolver: {
+      someStr: () => 'New String',
+    },
+  })
+
+  const schema = build.toSchema()
+
+  const { data } = await graphql({
+    schema,
+    source: '{ getModel(where: {}) { someInt someStr }}',
+  })
+  expect(data.getModel).toEqual({
+    someInt: 123,
+    someStr: 'New String',
+  })
+})

src/createBuild/index.ts

@@ -2,7 +2,7 @@ import { IFieldResolver, makeExecutableSchema } from 'graphql-tools'
 
 import { forEach, identity } from 'lodash'
 import { generateTypeDefs } from './generateTypeDefs'
-import { createAddType } from './method-addType'
+import { AddObjectTypeConfig, createAddType } from './method-addType'
 import { resolvablesCreator } from './method-resolvablesCreator'
 import {
   AddResolvableConfig,
@@ -102,6 +102,26 @@ export const createBuild = <BuildMode = null, Context = any>(
     },
   )
 
+  const extendType = <Source>(
+    typeName: string,
+    config: AddObjectTypeConfig<BuildMode, Source, Context>,
+  ) => {
+    const baseConfig = types.type[typeName]
+    if (!baseConfig)
+      throw new Error('Cannot extend an type that is not defined!')
+    if (config.resolver) addResolvers(typeName, config.resolver)
+    const fields = convertSimpleFieldsToFields(buildModeResolver(config.fields))
+    const interfaces = baseConfig.interface
+      .split('&')
+      .concat((buildModeResolver(config.interface) || '').split('&'))
+      .filter(_ => _)
+    types.type[typeName] = {
+      // adding new fields
+      fields: { ...baseConfig.fields, ...fields },
+      interface: interfaces.join('&'),
+    }
+  }
+
   const builder: Build<BuildMode, Context> = {
     type: GQLBUILDER,
     buildMode,
@@ -110,6 +130,7 @@ export const createBuild = <BuildMode = null, Context = any>(
     addResolver,
     addSubscription: createResolvable('Subscription'),
     addType,
+    extendType,
     isScalar: type =>
       ['String', 'Int', 'Float', 'ID'].includes(type) ||
       types.scalar.includes(type),

src/createBuild/types.ts

@@ -3,7 +3,7 @@ import { IFieldResolver, IResolvers, ITypeDefinitions } from 'graphql-tools'
 
 import { GQLBUILDER } from '../types/constants'
 
-import { createAddType } from './method-addType'
+import { AddObjectTypeConfig, createAddType } from './method-addType'
 
 // Context == GraphQLContext ({ user: {…}, db: DBConnection })
 // BuildMode == BuildMode of the build ('user' | 'admin')
@@ -24,6 +24,10 @@ export interface Build<BuildMode, Context> {
   ) => void
   addSubscription: AddResolvable<BuildMode, Context>
   addType: ReturnType<typeof createAddType>
+  extendType: <Source>(
+    typeName: string,
+    config: AddObjectTypeConfig<BuildMode, Source, Context>,
+  ) => void
   isScalar: (type: string) => boolean
   isType: (type: string) => boolean
   toSchema: () => GraphQLSchema