Migrate from factory function to single instance of Fastify plugin (#34)

Also fixes misprints in readme

README.md

@@ -87,18 +87,18 @@ Use the plugin provided by the library:
 const fastify = require('fastify')()
 const rTracer = require('cls-rtracer')
 
-// any third party middleware that does not need access to request ids goes here
+// any third party plugin that does not need access to request ids goes here
 // ...
 
-fastify.use(rTracer.fastifyPlugin())
-// optionally, you can override default middleware config:
-// fastify.use(rTracer.fastifyPlugin({
+fastify.register(rTracer.fastifyPlugin)
+// optionally, you can override default plugin config:
+// fastify.register(rTracer.fastifyPlugin, {
 //   useHeader: true,
 //   headerName: 'X-Your-Request-Header',
 //   useFastifyRequestId: true
 // }))
 
-// all code in middlewares, starting from here, has access to request ids
+// all code in plugins or handlers, starting from here, has access to request ids
 ```
 
 Obtain request id in middlewares on the incoming request:
@@ -204,12 +204,12 @@ const init = async () => {
   // ...
 
   await server.register({
-    plugin: rtracer.hapiPlugin
+    plugin: rTracer.hapiPlugin
   })
 
   // optionally, you can override default middleware config:
   //  await server.register({
-  //    plugin: rtracer.hapiPlugin,
+  //    plugin: rTracer.hapiPlugin,
   //    options: {
   //      useHeader: true,
   //      headerName: 'X-Your-Request-Header'

index.d.ts

@@ -31,10 +31,8 @@ export declare const expressMiddleware: (
 ) => void
 
 export declare const fastifyPlugin: (
-  options?: IFastifyOptions,
-) => (
   fastify: any,
-  options: any,
+  options: IFastifyOptions,
   done: (err?: any) => void,
 ) => void
 

samples/fastify.winston.js

@@ -28,7 +28,7 @@ const logger = createLogger({
 const Fastify = require('fastify')
 const app = new Fastify()
 
-app.register(rTracer.fastifyPlugin())
+app.register(rTracer.fastifyPlugin)
 
 app.get('/', async (request, reply) => {
   logger.info('Starting request handling')

src/rtracer.js

@@ -42,7 +42,7 @@ const expressMiddleware = ({
 }
 
 /**
- * Generates a request tracer plugin for Fastify.
+ * Request tracer plugin for Fastify.
  *
  * @param {Object} options possible options
  * @param {boolean} options.useHeader respect request header flag
@@ -52,34 +52,34 @@ const expressMiddleware = ({
  * @param {boolean} options.useFastifyRequestId respect Fastify request id flag
  *                                    (default: `false`)
  */
-const fastifyPlugin = ({
-  useHeader = false,
-  headerName = 'X-Request-Id',
-  useFastifyRequestId = false
-} = {}) => {
-  const plugin = (fastify, _, next) => {
-    fastify.addHook('onRequest', (request, reply, done) => {
-      let requestId
-      if (useHeader) {
-        requestId = request.headers[headerName.toLowerCase()]
-      }
-      if (useFastifyRequestId) {
-        requestId = requestId || request.id
-      }
-      requestId = requestId || uuidv1()
+const fastifyPlugin = (fastify, options, next) => {
+  const {
+    useHeader = false,
+    headerName = 'X-Request-Id',
+    useFastifyRequestId = false
+  } = options
+
+  fastify.addHook('onRequest', (request, reply, done) => {
+    let requestId
+    if (useHeader) {
+      requestId = request.headers[headerName.toLowerCase()]
+    }
+    if (useFastifyRequestId) {
+      requestId = requestId || request.id
+    }
+    requestId = requestId || uuidv1()
 
-      als.run(requestId, () => {
-        wrapHttpEmitters(request.raw, reply.res)
-        done()
-      })
+    als.run(requestId, () => {
+      wrapHttpEmitters(request.raw, reply.res)
+      done()
     })
-    next()
-  }
-  plugin[Symbol.for('skip-override')] = true
-  plugin[Symbol.for('fastify.display-name')] = pluginName
-  return plugin
+  })
+  next()
 }
 
+fastifyPlugin[Symbol.for('skip-override')] = true
+fastifyPlugin[Symbol.for('fastify.display-name')] = pluginName
+
 /**
  * Generates a request tracer middleware for Koa v2.
  *
@@ -138,7 +138,7 @@ const koaV1Middleware = ({
 }
 
 /**
- * A request tracer plugin for Hapi.
+ * Request tracer plugin for Hapi.
  *
  * @type {{once: boolean, name: string, register: hapiPlugin.register}}
  */
@@ -181,8 +181,8 @@ const runWithId = (fn, id) => {
 }
 
 /**
- * Returns request tracer id or `undefined` in case if the call is made from
- * an outside CLS context.
+ * Returns request tracer id or `undefined` in case if the call
+ * is made outside of the CLS context.
  */
 const id = () => als.getStore()
 

tests/fastify.test.js

@@ -13,7 +13,7 @@ const types = [pluginType, middlewareType]
 const register = (type, app, options) => {
   switch (type) {
     case pluginType:
-      return app.register(rTracer.fastifyPlugin(options))
+      return app.register(rTracer.fastifyPlugin, options)
     case middlewareType:
       return app.use(rTracer.fastifyMiddleware(options))
     default: