fixes #7

Signed-off-by: Matteo Collina <[email protected]>

README.md

@@ -49,6 +49,45 @@ export default function doWork () {
 }
 ```
 
+### enterWith
+
+If you need to alter the current asynchronous context, you can use the `enterWith` helper.
+
+```js
+import { before, describe, it } from "node:test";
+import Fastify from "fastify";
+import { app, start } from "fastify-asyncforge";
+import assert from "node:assert/strict";
+
+let fastify;
+
+async function build(config) {
+  const server = await Fastify();
+
+  server.decorate("config", config);
+  await start(server);
+  console.log("config from memo", app().config);
+
+  return server;
+}
+
+describe("support exiting from a context", () => {
+  before(async () => {
+    fastify = await build({ foo: "bar" });
+  });
+
+  it("throws", () => {
+    assert.throws(app);
+  });
+
+  it("does not throw using enterWith", () => {
+    fastify.enterWith();
+    assert.equal(app(), fastify);
+  });
+});
+```
+
+
 ## License
 
 MIT

index.js

@@ -3,12 +3,23 @@
 const fp = require('fastify-plugin')
 const { memo, setAll } = require('asyncforge')
 
-const app = memo()
-const request = memo()
-const reply = memo()
-const logger = memo()
+const app = memo('fastify.app')
+const request = memo('fastify.request')
+const reply = memo('fastify.reply')
+const logger = memo('fastify.logger')
 
 const fastifyAsyncForge = fp(function (fastify, opts, next) {
+  fastify.decorate('enterWith', function () {
+    try {
+      app()
+    } catch {
+      setAll({
+        [app.key]: this,
+        [logger.key]: this.log
+      })
+    }
+  })
+
   fastify.addHook('onRequest', async function (req, res) {
     setAll({
       [app.key]: this,

test/basic.test.js

@@ -60,3 +60,32 @@ test('basic helpers without start', async (t) => {
 
   await p.complete
 })
+
+test('fastify.enterWith', async (t) => {
+  const p = tspl(t, { plan: 7 })
+  const fastify = Fastify()
+
+  await fastify.register(fastifyAsyncForge)
+
+  fastify.enterWith()
+
+  p.strictEqual(logger(), fastify.log)
+  p.strictEqual(app(), fastify)
+
+  fastify.get('/', async function (_request, _reply) {
+    p.strictEqual(app(), this)
+    p.strictEqual(request(), _request)
+    p.strictEqual(reply(), _reply)
+    p.strictEqual(logger(), _request.log)
+    return { hello: 'world' }
+  })
+
+  const res = await fastify.inject({
+    method: 'GET',
+    url: '/'
+  })
+
+  p.strictEqual(res.statusCode, 200)
+
+  await p.complete
+})

test/issue-7.test.mjs

@@ -0,0 +1,30 @@
+import { before, describe, it } from 'node:test'
+import Fastify from 'fastify'
+import { app, start } from '../index.js'
+import assert from 'node:assert/strict'
+
+let fastify
+
+async function build (config) {
+  const server = await Fastify()
+
+  server.decorate('config', config)
+  await start(server)
+
+  return server
+}
+
+describe('support exiting from a context', () => {
+  before(async () => {
+    fastify = await build({ foo: 'bar' })
+  })
+
+  it('throws', () => {
+    assert.throws(app)
+  })
+
+  it('does not throw using enterWith', () => {
+    fastify.enterWith()
+    assert.equal(app(), fastify)
+  })
+})