feat: Output code property when it doesn't start with standard prefix.

Author: ShogunPanda

README.md

@@ -37,6 +37,7 @@ The handler response format will compatible with standard fastify error response
 }
 ```
 
+If the original error's `code` properties does not start with `HTTP_ERROR_` ([http-errors-enhanced](https://github.com/ShogunPanda/http-errors-enhanced) standard error prefix), then the `code` is also included in output object.
 In addition, the response headers will contain all headers defined in `error.headers` and the response body will contain all additional enumerable properties of the error.
 
 To clarify, take this server as a example:
@@ -49,7 +50,10 @@ server.register(require('fastify-http-errors-enhanced'))
 
 server.get('/invalid', {
   handler: async function (request, reply) {
-    throw new NotFoundError('You are not supposed to reach this.', { header: { 'X-Req-Id': request.id, id: 123 } })
+    throw new NotFoundError('You are not supposed to reach this.', {
+      header: { 'X-Req-Id': request.id, id: 123 },
+      code: 'UNREACHABLE'
+    })
   }
 })
 
@@ -65,6 +69,7 @@ When hitting `/invalid` it will return the following:
 ```json
 {
   "error": "Not Found",
+  "code": "UNREACHABLE",
   "message": "You are not supposed to reach this.",
   "statusCode": 404,
   "id": 123

package.json

@@ -39,7 +39,7 @@
   "dependencies": {
     "ajv": "^6.12.6",
     "fastify-plugin": "^3.0.0",
-    "http-errors-enhanced": "^0.3.0"
+    "http-errors-enhanced": "^0.4.2"
   },
   "devDependencies": {
     "@cowtech/eslint-config": "^7.10.1",

test/index.test.ts

@@ -53,6 +53,14 @@ function routes(instance: FastifyInstance, _options: unknown, done: Callback): v
     }
   })
 
+  instance.get('/error-with-code', {
+    async handler(): Promise<void> {
+      const error = createError(BAD_GATEWAY, 'This was the error message.', { code: 'CODE' })
+
+      throw error
+    }
+  })
+
   instance.get('/weird-code', {
     async handler(): Promise<void> {
       const error = new BadGatewayError('This was the error message.')
@@ -233,6 +241,20 @@ t.test('Plugin', (t: Test) => {
       })
     })
 
+    t.test('should correctly return error codes when not starting with the prefix', async (t: Test) => {
+      await buildServer()
+
+      const response = await server!.inject({ method: 'GET', url: '/error-with-code' })
+
+      t.equal(response.statusCode, BAD_GATEWAY)
+      t.deepEqual(JSON.parse(response.payload), {
+        error: 'Bad Gateway',
+        message: 'This was the error message.',
+        statusCode: BAD_GATEWAY,
+        code: 'CODE'
+      })
+    })
+
     t.test('should correctly return server duck-typed errors', async (t: Test) => {
       await buildServer()
 
@@ -569,7 +591,8 @@ t.test('Plugin', (t: Test) => {
       t.deepEqual(payload, {
         error: 'Internal Server Error',
         message: '[CODE] This was a generic message.',
-        statusCode: INTERNAL_SERVER_ERROR
+        statusCode: INTERNAL_SERVER_ERROR,
+        code: 'CODE'
       })
     })
 
@@ -581,7 +604,6 @@ t.test('Plugin', (t: Test) => {
       t.equal(response.statusCode, INTERNAL_SERVER_ERROR)
 
       const payload = JSON.parse(response.payload)
-      console.log(JSON.stringify(payload, null, 2))
       t.match(payload.stack[1], /wrapValidationError \(\$ROOT\/node_modules\/fastify\/.+:\d+:\d+\)/)
       delete payload.stack