fix(redshift): misleading error for queries with no results

Author: sathiish-kumar

src/redshift/notebook/redshiftNotebookController.ts

@@ -5,7 +5,7 @@
  */
 
 import * as vscode from 'vscode'
-import { DefaultRedshiftClient, ExecuteQueryResponse } from '../../shared/clients/redshiftClient'
+import { DefaultRedshiftClient } from '../../shared/clients/redshiftClient'
 import { ConnectionParams } from '../models/models'
 import { RedshiftData } from 'aws-sdk'
 import { telemetry } from '../../shared/telemetry/telemetry'
@@ -84,16 +84,22 @@ export class RedshiftNotebookController {
             let nextToken: string | undefined
             // get all the pages of the result
             do {
-                const result: ExecuteQueryResponse = await this.redshiftClient!.executeQuery(
+                const result = await this.redshiftClient!.executeQuery(
                     connectionParams,
                     cell.document.getText(),
                     nextToken,
                     executionId
                 )
-                nextToken = result.statementResultResponse.NextToken
-                executionId = result.executionId
-                columnMetadata = result.statementResultResponse.ColumnMetadata
-                records.push(...result.statementResultResponse.Records)
+                if (result) {
+                    nextToken = result.statementResultResponse.NextToken
+                    executionId = result.executionId
+                    columnMetadata = result.statementResultResponse.ColumnMetadata
+                    records.push(...result.statementResultResponse.Records)
+                } else {
+                    return new vscode.NotebookCellOutput([
+                        vscode.NotebookCellOutputItem.text('No records.', 'text/plain'),
+                    ])
+                }
             } while (nextToken)
 
             if (columnMetadata) {

src/shared/clients/redshiftClient.ts

@@ -149,7 +149,7 @@ export class DefaultRedshiftClient {
         queryToExecute: string,
         nextToken?: string,
         executionId?: string
-    ): Promise<ExecuteQueryResponse> {
+    ): Promise<ExecuteQueryResponse | undefined> {
         const redshiftData = await this.redshiftDataClientProvider(this.regionCode)
         // if executionId is not passed in, that means that we're executing and retrieving the results of the query for the first time.
         if (!executionId) {
@@ -189,6 +189,8 @@ export class DefaultRedshiftClient {
                         throw new Error(
                             `Failed to run query: '${queryToExecute}': '${describeStatementResponse.Error}'`
                         )
+                    } else if (status === 'FINISHED') {
+                        return undefined
                     }
                     break
                 } else {