fix: handle graphql invalid response (#2582)

frontend/src/lib/components/DBSchemaExplorer.svelte

@@ -205,9 +205,16 @@ GROUP BY table_name".replace('{dataset.id}', dataset.id)
 									publicOnly: !!schema.public || !!schema.PUBLIC
 								}
 							} else {
-								$dbSchemas[resourcePath] = {
-									lang: 'graphql',
-									schema: testResult.result
+								if (typeof testResult.result !== 'object' || !('__schema' in testResult.result)) {
+									console.error('Invalid GraphQL schema')
+									if (drawer?.isOpen()) {
+										sendUserToast('Invalid GraphQL schema', true)
+									}
+								} else {
+									$dbSchemas[resourcePath] = {
+										lang: 'graphql',
+										schema: testResult.result
+									}
 								}
 							}
 						}

frontend/src/lib/components/TestConnection.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { JobService, Preview } from '$lib/gen'
+	import { CompletedJob, JobService, Preview } from '$lib/gen'
 
 	import { Database, Loader2 } from 'lucide-svelte'
 	import Button from './common/button/Button.svelte'
@@ -15,6 +15,7 @@
 			code: string
 			lang: string
 			argName: string
+			additionalCheck?: (testResult: CompletedJob) => CompletedJob
 		}
 	} = {
 		postgresql: {
@@ -40,7 +41,25 @@
 		graphql: {
 			code: '{ __typename }',
 			lang: 'graphql',
-			argName: 'api'
+			argName: 'api',
+			additionalCheck: (testResult: CompletedJob) => {
+				if (
+					testResult.success &&
+					(typeof testResult.result !== 'object' || !('__typename' in testResult.result))
+				) {
+					return {
+						...testResult,
+						result: {
+							error: {
+								message: 'Invalid GraphQL API response'
+							}
+						},
+						success: false
+					}
+				} else {
+					return testResult
+				}
+			}
 		}
 	}
 
@@ -64,13 +83,18 @@
 
 		tryEvery({
 			tryCode: async () => {
-				const testResult = await JobService.getCompletedJob({
+				let testResult = await JobService.getCompletedJob({
 					workspace: $workspaceStore!,
 					id: job
 				})
+				if (resourceScript.additionalCheck) {
+					testResult = resourceScript.additionalCheck(testResult)
+				}
 				loading = false
 				sendUserToast(
-					testResult.success ? 'Connection successful' : testResult.result?.['error']?.['message'],
+					testResult.success
+						? 'Connection successful'
+						: 'Connection error: ' + testResult.result?.['error']?.['message'],
 					!testResult.success
 				)
 			},