feat: add async HTTP context (#18)

Author: targos

adonis-typings/context.ts

@@ -45,6 +45,21 @@ declare module '@ioc:Adonis/Core/HttpContext' {
     extends MacroableConstructorContract<HttpContextContract> {
     app?: ApplicationContract
 
+    /**
+     * Whether async hooks are enabled and the async HTTP context can be used.
+     */
+    readonly asyncHttpContextEnabled: boolean
+
+    /**
+     * Returns the current HTTP context or null if there is none.
+     */
+    get(): HttpContextContract | null
+
+    /**
+     * Returns the current HTTP context or throws if there is none.
+     */
+    getOrFail(): HttpContextContract
+
     /**
      * Creates a new fake context instance for a given route.
      */

adonis-typings/request.ts

@@ -593,6 +593,7 @@ declare module '@ioc:Adonis/Core/Request' {
     allowMethodSpoofing: boolean
     getIp?: (request: RequestContract) => string
     trustProxy: (address: string, distance: number) => boolean
+    enableAsyncHttpContext?: boolean
   }
 
   /**

package.json

@@ -14,7 +14,7 @@
   "scripts": {
     "mrm": "mrm --preset=@adonisjs/mrm-preset",
     "pretest": "npm run lint",
-    "test": "node japaFile.js",
+    "test": "node japaFile.js && cross-env ASYNC_HOOKS=1 node japaFile.js",
     "clean": "del build",
     "compile": "npm run lint && npm run clean && tsc",
     "build": "npm run compile",
@@ -50,6 +50,7 @@
     "@types/supertest": "^2.0.11",
     "autocannon": "^7.3.0",
     "commitizen": "^4.2.3",
+    "cross-env": "^7.0.3",
     "cz-conventional-changelog": "^3.3.0",
     "del-cli": "^3.0.1",
     "eslint": "^7.26.0",

src/AsyncHttpContext/index.ts

@@ -0,0 +1,33 @@
+/**
+ * @adonisjs/http-server
+ *
+ * (c) Harminder Virk <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/// <reference path="../../adonis-typings/index.ts" />
+
+import { AsyncLocalStorage } from 'async_hooks'
+import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
+
+export let asyncHttpContextEnabled = false
+
+export function setAsyncHttpContextEnabled(enabled: boolean) {
+  asyncHttpContextEnabled = enabled
+}
+
+export const adonisLocalStorage = new AsyncLocalStorage<AsyncHttpContext>()
+
+export class AsyncHttpContext {
+  constructor(private ctx: HttpContextContract) {}
+
+  public getContext() {
+    return this.ctx
+  }
+
+  public run(callback: () => any) {
+    return adonisLocalStorage.run(this, callback)
+  }
+}

src/HttpContext/index.ts

@@ -24,6 +24,8 @@ import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext'
 import { Request } from '../Request'
 import { Response } from '../Response'
 import { processPattern } from '../helpers'
+import { adonisLocalStorage, asyncHttpContextEnabled } from '../AsyncHttpContext'
+import { Exception } from '@poppinss/utils'
 
 /**
  * Http context is passed to all route handlers, middleware,
@@ -35,6 +37,27 @@ export class HttpContext extends Macroable implements HttpContextContract {
    */
   public static app: ApplicationContract
 
+  public static get asyncHttpContextEnabled() {
+    return asyncHttpContextEnabled
+  }
+
+  public static get(): HttpContextContract | null {
+    const store = adonisLocalStorage.getStore()
+    return store !== undefined ? store.getContext() : null
+  }
+
+  public static getOrFail() {
+    const store = adonisLocalStorage.getStore()
+    if (store !== undefined) {
+      return store.getContext()
+    }
+    if (asyncHttpContextEnabled) {
+      throw new Exception('async HTTP context accessed outside of a request context')
+    } else {
+      throw new Exception('async HTTP context is disabled')
+    }
+  }
+
   /**
    * A unique key for the current route
    */

src/Server/index.ts

@@ -27,6 +27,11 @@ import { HttpContext } from '../HttpContext'
 import { RequestHandler } from './RequestHandler'
 import { MiddlewareStore } from '../MiddlewareStore'
 import { ExceptionManager } from './ExceptionManager'
+import {
+  asyncHttpContextEnabled,
+  AsyncHttpContext,
+  setAsyncHttpContextEnabled,
+} from '../AsyncHttpContext'
 
 /**
  * Server class handles the HTTP requests by using all Adonis micro modules.
@@ -80,6 +85,8 @@ export class Server implements ServerContract {
     if (httpConfig.cookie.maxAge && typeof httpConfig.cookie.maxAge === 'string') {
       httpConfig.cookie.maxAge = ms(httpConfig.cookie.maxAge) / 1000
     }
+
+    setAsyncHttpContextEnabled(httpConfig.enableAsyncHttpContext || false)
   }
 
   /**
@@ -123,6 +130,13 @@ export class Server implements ServerContract {
     )
   }
 
+  /**
+   * Returns a new async HTTP context for the new request
+   */
+  private getAsyncContext(ctx: HttpContextContract): AsyncHttpContext {
+    return new AsyncHttpContext(ctx)
+  }
+
   /**
    * Define custom error handler to handler all errors
    * occurred during HTTP request
@@ -161,6 +175,19 @@ export class Server implements ServerContract {
     const requestAction = this.getProfilerRow(request)
     const ctx = this.getContext(request, response, requestAction)
 
+    if (asyncHttpContextEnabled) {
+      const asyncContext = this.getAsyncContext(ctx)
+      return asyncContext.run(() => this.handleImpl(ctx, requestAction, res))
+    } else {
+      this.handleImpl(ctx, requestAction, res)
+    }
+  }
+
+  private async handleImpl(
+    ctx: HttpContext,
+    requestAction: ProfilerRowContract,
+    res: ServerResponse
+  ) {
     /*
      * Handle request by executing hooks, request middleware stack
      * and route handler

test-helpers/index.ts

@@ -30,6 +30,7 @@ export const requestConfig: RequestConfig = {
   trustProxy: proxyaddr.compile('loopback'),
   subdomainOffset: 2,
   generateRequestId: true,
+  enableAsyncHttpContext: Boolean(process.env.ASYNC_HOOKS),
 }
 
 export const responseConfig: ResponseConfig = {
@@ -59,7 +60,8 @@ export async function setupApp(providers?: string[]) {
 		export const appKey = '${appSecret}'
 		export const http = {
 			trustProxy: () => true,
-			cookie: {}
+			cookie: {},
+      enableAsyncHttpContext: ${process.env.ASYNC_HOOKS ? 'true' : 'false'}
 		}
 	`
   )

test/server.spec.ts

@@ -19,6 +19,7 @@ import { ProfilerAction, ProfilerRow } from '@ioc:Adonis/Core/Profiler'
 
 import { Server } from '../src/Server'
 import { serverConfig, fs, setupApp, encryption } from '../test-helpers'
+import { HttpContext } from '../src/HttpContext'
 
 test.group('Server | Response handling', (group) => {
   group.afterEach(async () => {
@@ -1257,4 +1258,74 @@ test.group('Server | all', (group) => {
     const { body } = await supertest(httpServer).get(url).expect(200)
     assert.deepEqual(body, { hasValidSignature: true })
   })
+
+  if (process.env.ASYNC_HOOKS) {
+    test('async HTTP context (enabled)', async (assert) => {
+      const app = await setupApp()
+      const server = new Server(app, encryption, serverConfig)
+
+      server.router.get('/', async (ctx) => {
+        return {
+          enabled: HttpContext.asyncHttpContextEnabled,
+          get: HttpContext.get() === ctx,
+          getOrFail: HttpContext.getOrFail() === ctx,
+        }
+      })
+
+      server.optimize()
+
+      const httpServer = createServer(server.handle.bind(server))
+
+      assert.strictEqual(HttpContext.asyncHttpContextEnabled, true)
+      assert.strictEqual(HttpContext.get(), null)
+      assert.throws(
+        () => HttpContext.getOrFail(),
+        'async HTTP context accessed outside of a request context'
+      )
+
+      const { body } = await supertest(httpServer).get('/').expect(200)
+      assert.deepStrictEqual(body, {
+        enabled: true,
+        get: true,
+        getOrFail: true,
+      })
+    })
+  } else {
+    test('async HTTP context (disabled)', async (assert) => {
+      const app = await setupApp()
+      const server = new Server(app, encryption, serverConfig)
+
+      server.errorHandler(async (error, { response }) => {
+        response.status(200).send(error.message)
+      })
+
+      server.router.get('/', async () => {
+        return {
+          enabled: HttpContext.asyncHttpContextEnabled,
+          get: HttpContext.get() === null,
+        }
+      })
+
+      server.router.get('/fail', async () => {
+        return HttpContext.getOrFail()
+      })
+
+      server.optimize()
+
+      const httpServer = createServer(server.handle.bind(server))
+
+      assert.strictEqual(HttpContext.asyncHttpContextEnabled, false)
+      assert.strictEqual(HttpContext.get(), null)
+      assert.throws(() => HttpContext.getOrFail(), 'async HTTP context is disabled')
+
+      const { body } = await supertest(httpServer).get('/').expect(200)
+      assert.deepStrictEqual(body, {
+        enabled: false,
+        get: true,
+      })
+
+      const { text } = await supertest(httpServer).get('/fail').expect(200)
+      assert.strictEqual(text, 'async HTTP context is disabled')
+    })
+  }
 })