Stream reject on error refactor (#212)

Better error handling of authFetch errors: added classes ValidationError and NotFoundError.

Also smaller changes:
- added missing id field to StreamPermission
- strict type check of parameter in getOrCreateStream()

Author: teogeb

src/rest/ErrorCode.ts

@@ -1,20 +0,0 @@
-export enum ErrorCode {
-    NOT_FOUND = 'NOT_FOUND',
-    VALIDATION_ERROR = 'VALIDATION_ERROR',
-    UNKNOWN = 'UNKNOWN'
-}
-
-export const parseErrorCode = (body: string) => {
-    let json
-    try {
-        json = JSON.parse(body)
-    } catch (err) {
-        return ErrorCode.UNKNOWN
-    }
-    const code = json.code
-    const keys = Object.keys(ErrorCode)
-    if (keys.includes(code)) {
-        return code as ErrorCode
-    }
-    return ErrorCode.UNKNOWN
-}

src/rest/StreamEndpoints.ts

@@ -10,10 +10,9 @@ import Stream, { StreamOperation, StreamProperties } from '../stream'
 import StreamPart from '../stream/StreamPart'
 import { isKeyExchangeStream } from '../stream/KeyExchange'
 
-import authFetch, { AuthFetchError } from './authFetch'
+import authFetch, { ErrorCode, NotFoundError } from './authFetch'
 import { Todo } from '../types'
 import StreamrClient from '../StreamrClient'
-import { ErrorCode } from './ErrorCode'
 // TODO change this import when streamr-client-protocol exports StreamMessage type or the enums types directly
 import { ContentType, EncryptionType, SignatureType, StreamMessageType } from 'streamr-client-protocol/dist/src/protocol/message_layer/StreamMessage'
 
@@ -120,7 +119,7 @@ export class StreamEndpoints {
             // @ts-expect-error
             public: false,
         })
-        return json[0] ? new Stream(this.client, json[0]) : Promise.reject(new AuthFetchError('', undefined, undefined, ErrorCode.NOT_FOUND))
+        return json[0] ? new Stream(this.client, json[0]) : Promise.reject(new NotFoundError('Stream: name=' + name))
     }
 
     async createStream(props?: StreamProperties) {
@@ -139,7 +138,7 @@ export class StreamEndpoints {
         return new Stream(this.client, json)
     }
 
-    async getOrCreateStream(props: { id?: string, name?: string }) {
+    async getOrCreateStream(props: { id: string, name?: never } | { id?: never, name: string }) {
         this.client.debug('getOrCreateStream %o', {
             props,
         })
@@ -151,9 +150,8 @@ export class StreamEndpoints {
             }
             const stream = await this.getStreamByName(props.name!)
             return stream
-        } catch (err) {
-            const isNotFoundError = (err instanceof AuthFetchError) && (err.errorCode === ErrorCode.NOT_FOUND)
-            if (!isNotFoundError) {
+        } catch (err: any) {
+            if (err.errorCode !== ErrorCode.NOT_FOUND) {
                 throw err
             }
         }

src/rest/authFetch.ts

@@ -2,32 +2,66 @@ import fetch, { Response } from 'node-fetch'
 import Debug from 'debug'
 
 import { getVersionString } from '../utils'
-import { ErrorCode, parseErrorCode } from './ErrorCode'
 import Session from '../Session'
 
+export enum ErrorCode {
+    NOT_FOUND = 'NOT_FOUND',
+    VALIDATION_ERROR = 'VALIDATION_ERROR',
+    UNKNOWN = 'UNKNOWN'
+}
+
 export const DEFAULT_HEADERS = {
     'Streamr-Client': `streamr-client-javascript/${getVersionString()}`,
 }
 
 export class AuthFetchError extends Error {
     response?: Response
     body?: any
-    errorCode?: ErrorCode
+    errorCode: ErrorCode
 
     constructor(message: string, response?: Response, body?: any, errorCode?: ErrorCode) {
+        const typePrefix = errorCode ? errorCode + ': ' : ''
         // add leading space if there is a body set
         const bodyMessage = body ? ` ${(typeof body === 'string' ? body : JSON.stringify(body).slice(0, 1024))}...` : ''
-        super(message + bodyMessage)
+        super(typePrefix + message + bodyMessage)
         this.response = response
         this.body = body
-        this.errorCode = errorCode
+        this.errorCode = errorCode || ErrorCode.UNKNOWN
 
         if (Error.captureStackTrace) {
             Error.captureStackTrace(this, this.constructor)
         }
     }
 }
 
+export class ValidationError extends AuthFetchError {
+    constructor(message: string, response?: Response, body?: any) {
+        super(message, response, body, ErrorCode.VALIDATION_ERROR)
+    }
+}
+
+export class NotFoundError extends AuthFetchError {
+    constructor(message: string, response?: Response, body?: any) {
+        super(message, response, body, ErrorCode.NOT_FOUND)
+    }
+}
+
+const ERROR_TYPES = new Map<ErrorCode, typeof AuthFetchError>()
+ERROR_TYPES.set(ErrorCode.VALIDATION_ERROR, ValidationError)
+ERROR_TYPES.set(ErrorCode.NOT_FOUND, NotFoundError)
+ERROR_TYPES.set(ErrorCode.UNKNOWN, AuthFetchError)
+
+const parseErrorCode = (body: string) => {
+    let json
+    try {
+        json = JSON.parse(body)
+    } catch (err) {
+        return ErrorCode.UNKNOWN
+    }
+    const { code } = json
+    return code in ErrorCode ? code : ErrorCode.UNKNOWN
+}
+
 const debug = Debug('StreamrClient:utils:authfetch') // TODO: could use the debug instance from the client? (e.g. client.debug.extend('authFetch'))
 
 let ID = 0
@@ -78,6 +112,8 @@ export default async function authFetch<T extends object>(url: string, session?:
         return authFetch<T>(url, session, options, true)
     } else {
         debug('%d %s – failed', id, url)
-        throw new AuthFetchError(`Request ${id} to ${url} returned with error code ${response.status}.`, response, body, parseErrorCode(body))
+        const errorCode = parseErrorCode(body)
+        const ErrorClass = ERROR_TYPES.get(errorCode)!
+        throw new ErrorClass(`Request ${id} to ${url} returned with error code ${response.status}.`, response, body, errorCode)
     }
 }

src/stream/index.ts

@@ -6,6 +6,7 @@ import StreamrClient from '../StreamrClient'
 import { Todo } from '../types'
 
 interface StreamPermisionBase {
+    id: number
     operation: StreamOperation
 }
 
@@ -72,6 +73,8 @@ export default class Stream {
     // TODO add field definitions for all fields
     // @ts-expect-error
     id: string
+    // @ts-expect-error
+    name: string
     config: {
         fields: Field[];
     } = { fields: [] }

test/integration/StreamEndpoints.test.js renamed to test/integration/StreamEndpoints.test.ts

@@ -1,4 +1,6 @@
-import { ethers } from 'ethers'
+import { ethers, Wallet } from 'ethers'
+import { NotFoundError, ValidationError } from '../../src/rest/authFetch'
+import Stream, { StreamOperation } from '../../src/stream'
 
 import StreamrClient from '../../src/StreamrClient'
 import { uid } from '../utils'
@@ -9,17 +11,17 @@ import config from './config'
  * These tests should be run in sequential order!
  */
 
-function TestStreamEndpoints(getName) {
-    let client
-    let wallet
-    let createdStream
+function TestStreamEndpoints(getName: () => string) {
+    let client: StreamrClient
+    let wallet: Wallet
+    let createdStream: Stream
 
     const createClient = (opts = {}) => new StreamrClient({
         ...config.clientOptions,
         autoConnect: false,
         autoDisconnect: false,
         ...opts,
-    })
+    } as any)
 
     beforeAll(() => {
         wallet = ethers.Wallet.createRandom()
@@ -53,7 +55,7 @@ function TestStreamEndpoints(getName) {
         })
 
         it('invalid id', () => {
-            return expect(() => client.createStream({ id: 'invalid.eth/foobar' })).rejects.toThrow()
+            return expect(() => client.createStream({ id: 'invalid.eth/foobar' })).rejects.toThrow(ValidationError)
         })
     })
 
@@ -66,7 +68,7 @@ function TestStreamEndpoints(getName) {
 
         it('get a non-existing Stream', async () => {
             const id = `${wallet.address}/StreamEndpoints-integration-nonexisting-${Date.now()}`
-            return expect(() => client.getStream(id)).rejects.toThrow()
+            return expect(() => client.getStream(id)).rejects.toThrow(NotFoundError)
         })
     })
 
@@ -79,7 +81,7 @@ function TestStreamEndpoints(getName) {
 
         it('get a non-existing Stream', async () => {
             const name = `${wallet.address}/StreamEndpoints-integration-nonexisting-${Date.now()}`
-            return expect(() => client.getStreamByName(name)).rejects.toThrow()
+            return expect(() => client.getStreamByName(name)).rejects.toThrow(NotFoundError)
         })
     })
 
@@ -205,25 +207,25 @@ function TestStreamEndpoints(getName) {
         })
 
         it('Stream.hasPermission', async () => {
-            expect(await createdStream.hasPermission('stream_share', wallet.address)).toBeTruthy()
+            expect(await createdStream.hasPermission(StreamOperation.STREAM_SHARE, wallet.address)).toBeTruthy()
         })
 
         it('Stream.grantPermission', async () => {
-            await createdStream.grantPermission('stream_subscribe', null) // public read
-            expect(await createdStream.hasPermission('stream_subscribe', null)).toBeTruthy()
+            await createdStream.grantPermission(StreamOperation.STREAM_SUBSCRIBE, undefined) // public read
+            expect(await createdStream.hasPermission(StreamOperation.STREAM_SUBSCRIBE, undefined)).toBeTruthy()
         })
 
         it('Stream.revokePermission', async () => {
-            const publicRead = await createdStream.hasPermission('stream_subscribe', null)
-            await createdStream.revokePermission(publicRead.id)
-            expect(!(await createdStream.hasPermission('stream_subscribe', null))).toBeTruthy()
+            const publicRead = await createdStream.hasPermission(StreamOperation.STREAM_SUBSCRIBE, undefined)
+            await createdStream.revokePermission(publicRead!.id)
+            expect(!(await createdStream.hasPermission(StreamOperation.STREAM_SUBSCRIBE, undefined))).toBeTruthy()
         })
     })
 
     describe('Stream deletion', () => {
         it('Stream.delete', async () => {
             await createdStream.delete()
-            return expect(() => client.getStream(createdStream.id)).rejects.toThrow()
+            return expect(() => client.getStream(createdStream.id)).rejects.toThrow(NotFoundError)
         })
     })