Add 100% test coverage for jsonrpc server

packages/jsonrpc/src/server.test.ts

@@ -5,7 +5,15 @@ import bodyParser from 'body-parser'
 
 describe('jsonrpc', () => {
 
-  class Service {
+  interface IService {
+    add(a: number, b: number): number
+    delay(): Promise<void>
+    syncError(message: string): void
+    asyncError(message: string): Promise<void>
+    httpError(statusCode: number, message: string): Promise<void>
+  }
+
+  class Service implements IService {
     constructor(readonly time: number) {}
     add(a: number, b: number) {
       return a + b
@@ -13,63 +21,141 @@ describe('jsonrpc', () => {
     multiply(...numbers: number[]) {
       return numbers.reduce((a, b) => a * b, 1)
     }
-    delay() {
+    delay(): Promise<void> {
       return new Promise(resolve => {
         setTimeout(resolve, this.time)
       })
     }
+    syncError(message: string) {
+      throw new Error(message)
+    }
+    async asyncError(message: string) {
+      throw new Error(message)
+    }
+    async httpError(statusCode: number, message: string) {
+      const err: any = new Error(message)
+      err.statusCode = statusCode
+      err.errors = [{
+        message: 'one',
+      }]
+      throw err
+    }
   }
 
   function createApp() {
     const app = express()
     app.use(bodyParser.json())
-    app.use('/myService', jsonrpc(new Service(5), ['add', 'delay']))
-    app.use((err: any, req: any, res: any, next: any) => {
-      console.log(err)
-      next(err)
-    })
+    app.use('/myService', jsonrpc(new Service(5), [
+      'add',
+      'delay',
+      'syncError',
+      'asyncError',
+      'httpError',
+    ]))
     return app
   }
 
-  describe('errors', () => {
+  type ArgumentTypes<T> = T extends (...args: infer U) => infer R ? U: never
+  type RetType<T> = T extends (...args: any[]) => infer R ? R : never
+  type RetProm<T> = T extends Promise<any> ? T : Promise<T>
+  type PromisifyReturnType<T> = (...a: ArgumentTypes<T>) => RetProm<RetType<T>>
+  type Asyncified<T> = {
+    [K in keyof T]: PromisifyReturnType<T[K]>
+  }
 
+  function createClient<T>(app: express.Application) {
+    let id = 0
+    const proxy = new Proxy({}, {
+      get(obj, prop) {
+        id++
+        return async function makeRequest(...args: any[]) {
+          const result = await request(app)
+          .post('/myService')
+          .send({
+            jsonrpc: '2.0',
+            id,
+            method: prop,
+            params: args,
+          })
+          const {body} = result
+          if (body.error) {
+            throw body.error
+          }
+          return body.result
+        }
+      },
+    })
+    return proxy as Asyncified<T>
+  }
+
+  const client = createClient<IService>(createApp())
+
+  async function getError(promise: Promise<void>) {
+    let error
+    try {
+      await promise
+    } catch (err) {
+      error = err
+    }
+    expect(error).toBeTruthy()
+    return error
+  }
+
+  describe('errors', () => {
+    it('handles sync errors', async () => {
+      const response = await request(createApp())
+      .post('/myService')
+      .send({
+        id: 1,
+        jsonrpc: '2.0',
+        method: 'syncError',
+        params: ['test'],
+      })
+      .expect(500)
+      expect(response.body.id).toEqual(1)
+      expect(response.body).toEqual({
+        jsonrpc: '2.0',
+        id: 1,
+        result: null,
+        error: {
+          code: -32000,
+          message: 'Server error',
+        },
+      })
+    })
+    it('handles async errors', async () => {
+      const err = await getError(client.asyncError('test'))
+      expect(err.message).toBe('Server error')
+      expect(err.code).toBe(-32000)
+    })
+    it('returns an error when message is not in json format', async () => {
+      const result = await request(createApp())
+      .post('/myService')
+      .send('a=1')
+      .expect(400)
+      expect(result.body.error.message).toEqual('Parse error')
+    })
+    it('returns an error when message is not valid', async () => {
+      const result = await request(createApp())
+      .post('/myService')
+      .send({})
+      .expect(400)
+      expect(result.body.error.message).toEqual('Invalid Request')
+    })
+    it('converts http errors into jsonrpc errors', async () => {
+      const err = await getError(client.httpError(403, 'Unauthorized'))
+      expect(err.message).toEqual('Unauthorized')
+    })
   })
 
   describe('success', () => {
     it('can call method and receive results', async () => {
-      const response = await request(createApp())
-      .post('/myService')
-      .send({
-        jsonrpc: '2.0',
-        id: 1,
-        method: 'add',
-        params: [1, 2],
-      })
-      .expect(200)
-
-      expect(response.body).toEqual({
-        jsonrpc: '2.0',
-        id: 1,
-        result: 3,
-        error: null,
-      })
+      const result = await client.add(3, 4)
+      expect(result).toEqual(3 + 4)
     })
     it('handles promises', async () => {
-      const response = await request(createApp())
-      .post('/myService')
-      .send({
-        jsonrpc: '2.0',
-        id: 1,
-        method: 'delay',
-        params: [],
-      })
-      .expect(200)
-      expect(response.body).toEqual({
-        jsonrpc: '2.0',
-        id: 1,
-        // result: null,
-        error: null,
-      })
+      const response = await client.delay()
+      expect(response).toEqual(undefined)
     })
     it('handles synchronous notifications', async () => {
       await request(createApp())
@@ -96,12 +182,48 @@ describe('jsonrpc', () => {
   })
 
   describe('security', () => {
-    it('cannot call toString method', () => {
-
+    it('cannot call toString method', async () => {
+      await request(createApp())
+      .post('/myService')
+      .send({
+        id: 123,
+        jsonrpc: '2.0',
+        method: 'toString',
+        params: [],
+      })
+      .expect(404)
+      .expect({
+        jsonrpc: '2.0',
+        id: 123,
+        result: null,
+        error: {
+          code: -32601,
+          message: 'Method not found',
+          data: null,
+        },
+      })
     })
 
-    it('cannot call any other methods in objects prototype', () => {
-
+    it('cannot call any other methods in objects prototype', async () => {
+      await request(createApp())
+      .post('/myService')
+      .send({
+        id: 123,
+        jsonrpc: '2.0',
+        method: '__defineGetter__',
+        params: [],
+      })
+      .expect(404)
+      .expect({
+        jsonrpc: '2.0',
+        id: 123,
+        result: null,
+        error: {
+          code: -32601,
+          message: 'Method not found',
+          data: null,
+        },
+      })
     })
   })
 

packages/jsonrpc/src/server.ts

@@ -116,7 +116,7 @@ export function jsonrpc<T, F extends FunctionPropertyNames<T>>(
       !Array.isArray(params)
     ) {
       res.status(400)
-      return res.json(createErrorResponse(null, ERROR_INVALID_REQUEST))
+      return res.json(createErrorResponse(id, ERROR_INVALID_REQUEST))
     }
 
     if (
@@ -124,14 +124,20 @@ export function jsonrpc<T, F extends FunctionPropertyNames<T>>(
       typeof (rpcService as any)[method] !== 'function'
     ) {
       res.status(404)
-      return res.json(createErrorResponse(null, ERROR_METHOD_NOT_FOUND))
+      return res.json(createErrorResponse(id, ERROR_METHOD_NOT_FOUND))
     }
 
     // if (rpcService[method].arguments.length !== params.length) {
     //   return res.json(createErrorResponse(null, ERROR_INVALID_PARAMS))
     // }
 
-    const retValue = (rpcService as any)[method](...params)
+    // TODO handle synchronous errors
+    let retValue
+    try {
+      retValue = (rpcService as any)[method](...params)
+    } catch (err) {
+      return handleError(err, req, res, next)
+    }
 
     if (!isPromise(retValue)) {
       if (isNotification) {