added error parsing for vercel logs

lib/plugins/output-filter/vercel-format.js

@@ -7,13 +7,15 @@ const initDurationRegex = /Init\sDuration:\s([\d+]+\.[\d+]+)\sms/
 function formatVercelLogsOutput (context, config, eventEmitter, log, callback) {
   try {
     const parsedLog = parseVercelLog(log)
+    const error = parseVercelError(log.message)
+    const logToSend = { ...parsedLog, ...error }
 
     if (config.debug) {
-      console.log(parsedLog)
+      console.log(logToSend)
     }
 
-    if (parsedLog) {
-      callback(null, parsedLog)
+    if (logToSend) {
+      callback(null, logToSend)
     }
   } catch (e) {
     if (config.debug) {
@@ -56,4 +58,45 @@ function parseVercelLog (log) {
   }
 }
 
+function parseVercelError (message) {
+  try {
+    const errorLine = message
+      .split('\n')
+      .filter(line => line.length)
+      .filter(line => !(line.startsWith('REPORT') || line.startsWith('END') || line.startsWith('START')))
+      .map(line => removeErrorLineStart(line))
+      .shift()
+
+    const { errorType, errorMessage, stack } = tryParseErrorLine(errorLine)
+
+    return {
+      error: {
+        type: errorType,
+        message: errorMessage,
+        stack: stack.join('\n')
+      }
+    }
+  } catch (error) {
+    // return empty object it is not an error message
+    return {}
+  }
+}
+
+function removeErrorLineStart (line) {
+  const res = line.replace(/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z/, '')
+  return res.replace(/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/i, '')
+}
+
+function tryParseErrorLine (line) {
+  const json = line.match(/{[\s\S]*}/)
+  if (json === null) {
+    return line
+  }
+  try {
+    return JSON.parse(json[0])
+  } catch (e) {
+    return line
+  }
+}
+
 module.exports = formatVercelLogsOutput