Properly handle TestKit's FrontendError

Author: robsdedude

packages/testkit-backend/src/controller/local.js

@@ -1,6 +1,7 @@
 import Context from '../context'
 import Controller from './interface'
 import stringify from '../stringify'
+import { isFrontendError } from '../request-handlers'
 
 
 /**
@@ -24,7 +25,7 @@ export default class LocalController extends Controller {
   closeContext (contextId) {
     this._contexts.delete(contextId)
   }
-  
+
   async handle (contextId, { name, data }) {
     if (!this._contexts.has(contextId)) {
       throw new Error(`Context ${contextId} does not exist`)
@@ -58,15 +59,21 @@ export default class LocalController extends Controller {
 
   _writeError (contextId, e) {
     if (e.name) {
-      const id = this._contexts.get(contextId).addError(e)
-      this._writeResponse(contextId, 'DriverError', {
-        id,
-        msg: e.message + ' (' + e.code + ')',
-        code: e.code
-      })
+      if (isFrontendError(e)) {
+        this._writeResponse(contextId, 'FrontendError', {
+          msg: 'Simulating the client code throwing some error.',
+        })
+      } else {
+        const id = this._contexts.get(contextId).addError(e)
+        this._writeResponse(contextId, 'DriverError', {
+          id,
+          msg: e.message + ' (' + e.code + ')',
+          code: e.code
+        })
+      }
       return
     }
     this._writeBackendError(contextId, e)
   }
-  
+
 }

packages/testkit-backend/src/request-handlers.js

@@ -1,7 +1,7 @@
 import neo4j from './neo4j'
-import { 
-  cypherToNative, 
-  nativeToCypher, 
+import {
+  cypherToNative,
+  nativeToCypher,
 } from './cypher-native-binders.js'
 import {
   nativeToTestkitSummary,
@@ -21,6 +21,14 @@ const SUPPORTED_TLS = (() => {
   return [];
 })();
 
+export function throwFrontendError() {
+  throw new Error("TestKit FrontendError")
+}
+
+export function isFrontendError(error) {
+  return error.message === 'TestKit FrontendError'
+}
+
 export function NewDriver (context, data, wire) {
   const {
     uri,
@@ -107,8 +115,7 @@ export function DriverClose (context, data, wire) {
     .then(() => {
       wire.writeResponse('Driver', { id: driverId })
     })
-    .catch(err => wire.writeError(err)) 
-    .finally(() => context.removeDriver(driverId))
+    .catch(err => wire.writeError(err))
 }
 
 export function NewSession (context, data, wire) {
@@ -213,8 +220,6 @@ export function ResultPeek (context, data, wire) {
 }
 
 export function ResultConsume (context, data, wire) {
-  
-
   const { resultId } = data
   const result = context.getResult(resultId)
 
@@ -276,7 +281,7 @@ export function RetryablePositive (context, data, wire) {
 
 export function RetryableNegative (context, data, wire) {
   const { sessionId, errorId } = data
-  const error = context.getError(errorId) || new Error('Client error')
+  const error = context.getError(errorId) || new Error('TestKit FrontendError')
   context.getTxsBySessionId(sessionId).forEach(tx => {
     tx.reject(error)
   })