feat(#4667): optionable body parsing

lib/interceptor/response-error.js

@@ -5,41 +5,49 @@ const DecoratorHandler = require('../handler/decorator-handler')
 const { ResponseError } = require('../core/errors')
 
 class ResponseErrorHandler extends DecoratorHandler {
-  #statusCode
-  #contentType
-  #decoder
-  #headers
-  #body
-
-  constructor (_opts, { handler }) {
+  #contentType = ''
+  #isParseableRespnse = false
+  #statusCode = null
+  #decoder = null
+  #headers = null
+  #body = null
+  #opts = null
+
+  constructor (opts, { handler }) {
     super(handler)
+    this.#opts = opts
   }
 
-  #checkContentType (contentType) {
-    return (this.#contentType ?? '').indexOf(contentType) === 0
+  #isParsableContentType (contentType) {
+    return (
+      this.#contentType.indexOf('application/json') !== -1 ||
+      this.#contentType.indexO('text/plain') !== -1
+    )
   }
 
   onRequestStart (controller, context) {
-    this.#statusCode = 0
-    this.#contentType = null
-    this.#decoder = null
-    this.#headers = null
-    this.#body = ''
-
     return super.onRequestStart(controller, context)
   }
 
   onResponseStart (controller, statusCode, headers, statusMessage) {
-    this.#statusCode = statusCode
-    this.#headers = headers
-    this.#contentType = headers['content-type']
-
     if (this.#statusCode < 400) {
-      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+      return super.onResponseStart(
+        controller,
+        statusCode,
+        headers,
+        statusMessage
+      )
     }
 
-    if (this.#checkContentType('application/json') || this.#checkContentType('text/plain')) {
+    this.#statusCode = statusCode
+    this.#headers = headers
+    this.#contentType = headers['content-type']
+    this.#isParseableRespnse = this.#isParsableContentType(this.#contentType)
+    if (this.#opts.shouldParseBody && this.#isParseableRespnse) {
+      this.#body = ''
       this.#decoder = new TextDecoder('utf-8')
+    } else {
+      this.#body = [] // pushing chunks instead
     }
   }
 
@@ -48,18 +56,28 @@ class ResponseErrorHandler extends DecoratorHandler {
       return super.onResponseData(controller, chunk)
     }
 
-    this.#body += this.#decoder?.decode(chunk, { stream: true }) ?? ''
+    if (Array.isArray(this.#body)) {
+      this.#body.push(chunk)
+    } else {
+      this.#body += this.#decoder?.decode(chunk, { stream: true }) ?? ''
+    }
   }
 
   onResponseEnd (controller, trailers) {
     if (this.#statusCode >= 400) {
-      this.#body += this.#decoder?.decode(undefined, { stream: false }) ?? ''
-
-      if (this.#checkContentType('application/json')) {
-        try {
-          this.#body = JSON.parse(this.#body)
-        } catch {
-          // Do nothing...
+      if (Array.isArray(this.#body)) this.#body = Buffer.concat(this.#body)
+      else {
+        this.#body += this.#decoder?.decode(undefined, { stream: false }) ?? ''
+        if (
+          this.#isParseableRespnse &&
+          // TODO: Story content-type as part of the handler
+          this.#contentType.indexOf('application/json') !== -1
+        ) {
+          try {
+            this.#body = JSON.parse(this.#body)
+          } catch {
+            // Do nothing...
+          }
         }
       }
 
@@ -87,8 +105,19 @@ class ResponseErrorHandler extends DecoratorHandler {
 }
 
 module.exports = () => {
-  return (dispatch) => {
+  return dispatch => {
     return function Intercept (opts, handler) {
+      if (
+        opts?.shouldParseBody != null &&
+        typeof opts.shouldParseBody !== 'boolean'
+      ) {
+        throw new TypeError('opts.shouldParseBody should be a boolean')
+      }
+
+      opts = {
+        shouldParseBody: opts?.shouldParseBody ?? true
+      }
+
       return dispatch(opts, new ResponseErrorHandler(opts, { handler }))
     }
   }