improve stack trace of errors

Author: bjrmatos

lib/client.js

@@ -47,6 +47,14 @@ class Client {
       const responseStream = request.post(optionsToUse)
 
       responseStream.on('error', (err) => {
+        const error = new Error('Error while executing request to remote server')
+
+        addStack(error, err.stack, {
+          stackPrefix: 'Request Error stack:'
+        })
+
+        error.message = `${error.message}. ${err.message}`
+
         reject(err)
       })
 
@@ -60,10 +68,21 @@ class Client {
             try {
               const errorMessage = JSON.parse(data.toString())
               const error = new Error(errorMessage.message)
+
+              addStack(error, errorMessage.stack, {
+                stripMessage: true,
+                stackPrefix: 'Remote stack: '
+              })
+
               error.remoteStack = errorMessage.stack
               reject(error)
             } catch (e) {
-              const err = new Error('Unknown error, status code ' + response.statusCode)
+              const err = new Error(`Error while executing request to remote server: Unknown error, status code ${response.statusCode}`)
+
+              addStack(err, e.stack, {
+                stackPrefix: 'Parsing Error stack:'
+              })
+
               err.response = response
               reject(err)
             }
@@ -117,3 +136,28 @@ function extractDataFromResponse (response, cb) {
   response.on('error', (err) => cb(err))
   response.pipe(writeStream)
 }
+
+function addStack (err, stack, { stackPrefix = '', stripMessage = false } = {}) {
+  if (stack != null && stack !== '') {
+    let newStack = stack
+    let originalStack = ''
+
+    if (err.stack != null && err.stack !== '') {
+      originalStack = `${err.stack}\n`
+    }
+
+    if (stripMessage) {
+      // to avoid duplicating message we strip the message
+      // from the stack if it is equals to the message of error
+      newStack = newStack.replace(/(\S+:) (.+)(\r?\n)/, (match, gLabel, gMessage, gRest) => {
+        if (err.message === gMessage) {
+          return `${gLabel}${gRest}`
+        }
+
+        return match
+      })
+    }
+
+    err.stack = `${originalStack}${stackPrefix}${newStack}`
+  }
+}