feat(presto-client): return back the whole error object (#17)

Author: alonsovb

.gitignore

@@ -21,3 +21,5 @@ npm-debug.log
 .DS_Store
 Thumbs.db
 
+# Nx files
+.nx

apps/nest-server/src/app/app.controller.ts

@@ -14,4 +14,13 @@ export class AppController {
       console.error(err)
     }
   }
+
+  @Get('presto-error')
+  async getDataWithError() {
+    try {
+      return await this.appService.getDataWithError()
+    } catch (err) {
+      console.error(err)
+    }
+  }
 }

apps/nest-server/src/app/app.service.ts

@@ -1,5 +1,5 @@
 import { Injectable } from '@nestjs/common'
-import PrestoClient, { PrestoClientConfig } from '@prestodb/presto-js-client'
+import PrestoClient, { PrestoClientConfig, PrestoError } from '@prestodb/presto-js-client'
 
 @Injectable()
 export class AppService {
@@ -18,9 +18,35 @@ export class AppService {
       )
       return { columns: results.columns, rows: results.data }
     } catch (error) {
-      return JSON.stringify({
-        error,
-      })
+      return (error as PrestoError).message
+    }
+  }
+
+  async getDataWithError(): Promise<unknown> {
+    const clientParams: PrestoClientConfig = {
+      catalog: 'tpch',
+      host: 'http://localhost',
+      port: 8080,
+      schema: 'sf1',
+      user: 'root',
+    }
+    const client = new PrestoClient(clientParams)
+    try {
+      const results = await client.query(`SELECT * FROM A SYNTAX ERROR`)
+      return { columns: results.columns, rows: results.data }
+    } catch (error) {
+      if (error instanceof PrestoError) {
+        /* eslint-disable no-console */
+        // The error here contains all the information returned by Presto directly
+        console.info(error.message)
+        console.info(error.name)
+        console.info(error.errorCode)
+        console.info(error.stack)
+        console.info(error.failureInfo.type)
+        return 'A Presto error ocurred, please check the service logs'
+      }
+      console.error(error)
+      return error
     }
   }
 }

presto-client/README.md

@@ -64,12 +64,7 @@ If the query succeeds, the PrestoQuery object will have the following properties
 - `data`: An array of arrays that contain the actual data for the results.
 - `queryId`: The ID of the query.
 
-If the query fails, the PrestoQuery object will have the following properties:
-
-- `error`: An object that contains information about the error.
-- `queryId`: The ID of the query.
-
-You can use the `error` property to get more information about the error that occurred. You can also use the `queryId` property to cancel the query or to get more information about the status of the query.
+If the query fails, you can catch the error as a PrestoError which contains all information returned by Presto.
 
 ### Example usage
 
@@ -86,12 +81,14 @@ const client = new PrestoClient({
 
 const query = `SELECT * FROM my_table`
 
-const prestoQuery = await client.query(query)
-
-if (prestoQuery.error) {
-  // Handle the error.
-} else {
-  // Use the results of the query.
+try {
+  const prestoQuery = await client.query(query)
+  const results = prestoQuery.data
+} catch (error) {
+  if (error instanceof PrestoError) {
+    // Handle the error.
+    console.error(error.errorCode)
+  }
 }
 ```
 

presto-client/src/client.ts

@@ -1,4 +1,4 @@
-import { PrestoClientConfig, PrestoQuery, PrestoResponse } from './client.types'
+import { PrestoClientConfig, PrestoError, PrestoQuery, PrestoResponse } from './client.types'
 
 export class PrestoClient {
   private baseUrl: string
@@ -54,6 +54,9 @@ export class PrestoClient {
     })
   }
 
+  /**
+   * @throws {PrestoError} If the underlying Presto engine returns an error
+   */
   async query(
     query: string,
     options?: {
@@ -110,7 +113,8 @@ export class PrestoClient {
       }
 
       if (prestoResponse.error) {
-        throw new Error(prestoResponse.error.errorName)
+        // Throw back the whole error object which contains all error information
+        throw new PrestoError(prestoResponse.error)
       }
 
       nextUri = prestoResponse?.nextUri

presto-client/src/client.types.ts

@@ -33,11 +33,16 @@ export interface PrestoResponse {
   updateType: string
 }
 
-export interface PrestoError {
+export interface PrestoErrorObject extends Error {
   errorCode: number
   errorName: string
   errorType: string
-  failureInfo: unknown
+  failureInfo: {
+    message: string
+    stack: string[]
+    suppressed: string[]
+    type: string
+  }
   message: string
 }
 
@@ -54,3 +59,18 @@ export interface PrestoQuery {
 export type GetPrestoDataParams = PrestoClientConfig & {
   query: string
 }
+
+export class PrestoError extends Error implements PrestoErrorObject {
+  errorCode: number
+  errorName: string
+  errorType: string
+  failureInfo: PrestoErrorObject['failureInfo']
+
+  constructor({ errorCode, errorName, errorType, failureInfo, message }: PrestoErrorObject) {
+    super(message)
+    this.errorCode = errorCode
+    this.errorName = errorName
+    this.errorType = errorType
+    this.failureInfo = failureInfo
+  }
+}