fix: context params and pass req and res in an object (#1295)

`req` and `res` are now also set by default in the GraphQL context.

BREAKING CHANGES:

- The function passed to `schema.addToContext` (known as a "Context Adder") no longer has its first parameter being the request object. Instead it now receives an object (known as the "Context Adder Lens") _containing_ the request object. In addition, on this lens, the response object can also be found. The lens exposes the request and response objects on properties `req` and `res` respectively. If you feel strongly that they should be `request` and `response` or any other thoughts you have please let us know on the issue tracker!

  before:

  ```ts
  schema.addToContext((req) => {
    // do something
  })
  ```

  after:

  ```ts
  schema.addToContext(({ req, res }}) => {
    // do something
  })
  ```

Author: Weakky

src/lib/add-to-context-extractor/extractor.spec.ts

@@ -2,6 +2,7 @@ import { isLeft } from 'fp-ts/lib/Either'
 import * as tsm from 'ts-morph'
 import { normalizePathsInData } from '../../lib/utils'
 import { extractContextTypes } from './extractor'
+import { DEFAULT_CONTEXT_TYPES } from './typegen'
 
 describe('syntax cases', () => {
   it('will extract from import name of nexus default export', () => {
@@ -141,6 +142,21 @@ it('extracts from returned object of referenced primitive value', () => {
   `)
 })
 
+it('can access all default context types', () => {
+  const allTypesExported = DEFAULT_CONTEXT_TYPES.typeImports.every(i => {
+    const project = new tsm.Project({
+      addFilesFromTsConfig: false,
+      skipFileDependencyResolution: true
+    })
+
+    const sourceFile = project.addSourceFileAtPath(i.modulePath + '.d.ts')
+
+    return sourceFile.getExportedDeclarations().has(i.name)
+  })
+
+  expect(allTypesExported).toEqual(true)
+})
+
 it('extracts from returned object of referenced object value', () => {
   expect(
     extract(`

src/lib/add-to-context-extractor/extractor.ts

@@ -42,13 +42,13 @@ function contribTypeLiteral(value: string): ContribTypeLiteral {
 /**
  * Extract types from all `addToContext` calls.
  */
-export function extractContextTypes(program: tsm.Project): Either<Exception, ExtractedContextTypes> {
+export function extractContextTypes(
+  program: tsm.Project,
+  defaultTypes: ExtractedContextTypes = { typeImports: [], types: [] }
+): Either<Exception, ExtractedContextTypes> {
   const typeImportsIndex: Record<string, TypeImportInfo> = {}
 
-  const contextTypeContributions: ExtractedContextTypes = {
-    typeImports: [],
-    types: [],
-  }
+  const contextTypeContributions: ExtractedContextTypes = defaultTypes
 
   const appSourceFiles = findModulesThatImportModule(program, 'nexus')
 

src/lib/add-to-context-extractor/typegen.ts

@@ -18,6 +18,18 @@ export const NEXUS_DEFAULT_RUNTIME_CONTEXT_TYPEGEN_PATH = fs.path(
   'index.d.ts'
 )
 
+export const DEFAULT_CONTEXT_TYPES: ExtractedContextTypes = {
+  typeImports: [
+    {
+      name: 'ContextAdderLens',
+      modulePath: require.resolve('../../../dist/runtime/schema/schema').split('.')[0],
+      isExported: true,
+      isNode: false,
+    },
+  ],
+  types: [{ kind: 'ref', name: 'ContextAdderLens' }],
+}
+
 /**
  * Run the pure extractor and then write results to a typegen module.
  */
@@ -28,7 +40,7 @@ export async function generateContextExtractionArtifacts(
   const errProject = createTSProject(layout, { withCache: true })
   if (isLeft(errProject)) return errProject
   const tsProject = errProject.right
-  const contextTypes = extractContextTypes(tsProject)
+  const contextTypes = extractContextTypes(tsProject, DEFAULT_CONTEXT_TYPES)
 
   if (isLeft(contextTypes)) {
     return contextTypes

src/runtime/app.ts

@@ -9,7 +9,6 @@ import { Index } from '../lib/utils'
 import * as Lifecycle from './lifecycle'
 import * as Schema from './schema'
 import * as Server from './server'
-import { ContextCreator } from './server/server'
 import * as Settings from './settings'
 import { assertAppNotAssembled } from './utils'
 
@@ -88,7 +87,7 @@ export type AppState = {
     schema: NexusSchema.core.NexusGraphQLSchema
     missingTypes: Index<NexusSchema.core.MissingType>
     loadedPlugins: RuntimeContributions<any>[]
-    createContext: ContextCreator
+    createContext: Schema.ContextAdder
   }
   running: boolean
   components: {
@@ -223,6 +222,11 @@ export function create(): App {
   app.schema.importType(builtinScalars.DateTime, 'date')
   app.schema.importType(builtinScalars.Json, 'json')
 
+  /**
+   * Add `req` and `res` to the context by default
+   */
+  app.schema.addToContext(params => params)
+
   return {
     ...app,
     private: {

src/runtime/schema/index.ts

@@ -1,2 +1,3 @@
-export { create, LazyState, Schema } from './schema'
+export { ContextAdder, create, LazyState, Schema } from './schema'
 export { SettingsData, SettingsInput } from './settings'
+

src/runtime/schema/schema.ts

@@ -17,7 +17,7 @@ import { createSchemaSettingsManager, SchemaSettingsManager } from './settings'
 import { mapSettingsAndPluginsToNexusSchemaConfig } from './settings-mapper'
 
 export type LazyState = {
-  contextContributors: ContextContributor[]
+  contextContributors: ContextAdder[]
   plugins: NexusSchema.core.NexusPlugin[]
   scalars: Scalars.Scalars
 }
@@ -40,8 +40,19 @@ export function createLazyState(): LazyState {
 export interface Request extends HTTP.IncomingMessage {
   log: NexusLogger.Logger
 }
+export interface Response extends HTTP.ServerResponse {}
 
-export type ContextContributor = (req: Request) => MaybePromise<Record<string, unknown>>
+export type ContextAdderLens = {
+  /**
+   * Incoming HTTP request
+   */
+  req: Request
+  /**
+   * Server response
+   */
+  res: Response
+}
+export type ContextAdder = (params: ContextAdderLens) => MaybePromise<Record<string, unknown>>
 
 type MiddlewareFn = (
   source: any,
@@ -66,7 +77,7 @@ export interface Schema extends NexusSchemaStatefulBuilders {
   /**
    * todo link to website docs
    */
-  addToContext(contextContributor: ContextContributor): void
+  addToContext(contextAdder: ContextAdder): void
 }
 
 /**
@@ -96,8 +107,8 @@ export function create(state: AppState): SchemaInternal {
       assertAppNotAssembled(state, 'app.schema.use', 'The Nexus Schema plugin you used will be ignored.')
       state.components.schema.plugins.push(plugin)
     },
-    addToContext(contextContributor) {
-      state.components.schema.contextContributors.push(contextContributor)
+    addToContext(contextAdder) {
+      state.components.schema.contextContributors.push(contextAdder)
     },
     middleware(fn) {
       api.use(

src/runtime/server/context.spec.ts

@@ -0,0 +1,71 @@
+import { makeSchema, queryType } from '@nexus/schema'
+import { IncomingMessage, ServerResponse } from 'http'
+import { Socket } from 'net'
+import { createRequestHandlerGraphQL } from './handler-graphql'
+import { NexusRequestHandler } from './server'
+import { errorFormatter } from './error-formatter'
+
+let handler: NexusRequestHandler
+let socket: Socket
+let req: IncomingMessage
+let res: ServerResponse
+let contextInput: any
+
+beforeEach(() => {
+  // todo actually use req body etc.
+  contextInput = null
+  socket = new Socket()
+  req = new IncomingMessage(socket)
+  res = new ServerResponse(req)
+  createHandler(
+    queryType({
+      definition(t) {
+        t.boolean('foo', () => false)
+      },
+    })
+  )
+})
+
+it('passes the request and response to the schema context', async () => {
+  reqPOST(`{ foo }`)
+
+  await handler(req, res)
+
+  expect(contextInput.req).toBeInstanceOf(IncomingMessage)
+  expect(contextInput.res).toBeInstanceOf(ServerResponse)
+})
+
+/**
+ * helpers
+ */
+
+function createHandler(...types: any) {
+  handler = createRequestHandlerGraphQL(
+    makeSchema({
+      outputs: false,
+      types,
+    }),
+    (params) => {
+      contextInput = params
+
+      return params
+    },
+    {
+      introspection: true,
+      errorFormatterFn: errorFormatter,
+      path: '/graphql',
+      playground: false,
+    }
+  )
+}
+
+function reqPOST(params: string | { query?: string; variables?: string }): void {
+  req.method = 'POST'
+  if (typeof params === 'string') {
+    ;(req as any).body = {
+      query: params,
+    }
+  } else {
+    ;(req as any).body = params
+  }
+}

src/runtime/server/handler-graphql.ts

@@ -1,7 +1,8 @@
 import { GraphQLError, GraphQLFormattedError, GraphQLSchema } from 'graphql'
+import { ContextAdder } from '../schema'
 import { ApolloServerless } from './apollo-server'
 import { log } from './logger'
-import { ContextCreator, NexusRequestHandler } from './server'
+import { NexusRequestHandler } from './server'
 import { PlaygroundInput } from './settings'
 
 type Settings = {
@@ -13,7 +14,7 @@ type Settings = {
 
 type CreateHandler = (
   schema: GraphQLSchema,
-  createContext: ContextCreator,
+  createContext: ContextAdder,
   settings: Settings
 ) => NexusRequestHandler
 

src/runtime/server/server.ts

@@ -4,10 +4,10 @@ import * as HTTP from 'http'
 import { HttpError } from 'http-errors'
 import * as Net from 'net'
 import * as Plugin from '../../lib/plugin'
-import { httpClose, httpListen, MaybePromise, noop } from '../../lib/utils'
+import { httpClose, httpListen, noop } from '../../lib/utils'
 import { AppState } from '../app'
 import * as DevMode from '../dev-mode'
-import { ContextContributor } from '../schema/schema'
+import { ContextAdder } from '../schema'
 import { assembledGuard } from '../utils'
 import { ApolloServerExpress } from './apollo-server'
 import { errorFormatter } from './error-formatter'
@@ -45,7 +45,7 @@ export interface Server {
 interface State {
   running: boolean
   httpServer: HTTP.Server
-  createContext: null | (() => ContextCreator<Record<string, any>, Record<string, any>>)
+  createContext: null | (() => ContextAdder)
   apolloServer: null | ApolloServerExpress
 }
 
@@ -183,37 +183,28 @@ const wrapHandlerWithErrorHandling = (handler: NexusRequestHandler): NexusReques
   }
 }
 
-type AnonymousRequest = Record<string, any>
-
-type AnonymousContext = Record<string, any>
-
-export type ContextCreator<
-  Req extends AnonymousRequest = AnonymousRequest,
-  Context extends AnonymousContext = AnonymousContext
-> = (req: Req) => MaybePromise<Context>
-
 /**
  * Combine all the context contributions defined in the app and in plugins.
  */
 function createContextCreator(
-  contextContributors: ContextContributor[],
+  contextContributors: ContextAdder[],
   plugins: Plugin.RuntimeContributions[]
-): ContextCreator {
-  const createContext: ContextCreator = async (req) => {
+): ContextAdder {
+  const createContext: ContextAdder = async (params) => {
     let context: Record<string, any> = {}
 
     // Integrate context from plugins
     for (const plugin of plugins) {
       if (!plugin.context) continue
-      const contextContribution = await plugin.context.create(req)
+      const contextContribution = plugin.context.create(params.req)
 
       Object.assign(context, contextContribution)
     }
 
     // Integrate context from app context api
     // TODO good runtime feedback to user if something goes wrong
     for (const contextContributor of contextContributors) {
-      const contextContribution = await contextContributor(req as any)
+      const contextContribution = await contextContributor(params)
 
       Object.assign(context, contextContribution)
     }

website/content/011-adoption-guides/010-nexus-schema-users.mdx

@@ -94,7 +94,7 @@ Nexus has an API for adding to context.
 +++ app.ts
 + import { schema } from 'nexus'
 
-+ schema.addToContext(req => {
++ schema.addToContext(({ req, res }) => {
 +   return { ... }
 + })
 

website/content/011-adoption-guides/020-prisma-users.mdx

@@ -22,7 +22,7 @@ import { schema } from 'nexus'
 
 const db = new PrismaClient()
 
-schema.addToContext(req => ({ db })) // exopse Prisma Client to all resolvers
+schema.addToContext(({ req, res }) => ({ db })) // expose Prisma Client to all resolvers
 
 schema.queryType({
   definition(t) {

website/content/040-api/01-nexus/01-schema.mdx

@@ -922,12 +922,16 @@ Sugar for creating arguments of type `Int` `String` `Float` `ID` `Boolean`.
 
 Add context to your graphql resolver functions. The objects returned by your context contributor callbacks will be shallow-merged into `ctx`. The `ctx` type will also accurately reflect the types you return from callbacks passed to `addToContext`.
 
+The incoming request and server response are passed to the callback in the following shape: `{ req: IncomingMessage, res: ServerResponse }`. See below how to use them.
+
 ### Example
 
+Defining arbitrary values to your GraphQL context
+
 ```ts
 import { schema } from 'nexus'
 
-schema.addToContext(_req => {
+schema.addToContext(({ req, res }) => {
   return {
     greeting: 'Howdy!',
   }
@@ -944,6 +948,30 @@ schema.queryType({
 })
 ```
 
+Forwarding the incoming request to your GraphQL Context
+
+```ts
+import { schema } from 'nexus'
+
+schema.addToContext(({ req, res }) => {
+  return {
+    req
+  }
+})
+
+schema.queryType({
+  definition(t) {
+    t.string('hello', {
+      resolve(_root, _args, ctx) {
+        if (ctx.req.headers['authorization']) {
+          /* ... */
+        }
+      },
+    })
+  },
+})
+```
+
 ## `use`
 
 Add schema plugins to your app. These plugins represent a subset of what framework plugins ([`app.use`](../../api/nexus/use) can do. This is useful when, for example, a schema plugin you would like to use has not integrated into any framework plugin. You can find a list of schema plugins [here](../../components-standalone/schema/plugins).