[Painless Lab][Serverless] Add integration tests (#172149)

## Summary

This PR adds serverless API integration tests for Painless Lab - for the
Observability and Security projects only, since Painless lab is disabled
in the Search project.

x-pack/test_serverless/api_integration/test_suites/common/painless_lab/index.ts

@@ -0,0 +1,16 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { FtrProviderContext } from '../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: FtrProviderContext) {
+  describe('Painless Lab API', function () {
+    this.tags(['esGate']);
+
+    loadTestFile(require.resolve('./painless_lab'));
+  });
+}

x-pack/test_serverless/api_integration/test_suites/common/painless_lab/painless_lab.ts

@@ -0,0 +1,51 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../ftr_provider_context';
+
+const API_BASE_PATH = '/api/painless_lab';
+
+export default function ({ getService }: FtrProviderContext) {
+  const supertest = getService('supertest');
+  const svlCommonApi = getService('svlCommonApi');
+
+  describe('Painless Lab Routes', function () {
+    describe('Execute', () => {
+      it('should execute a valid painless script', async () => {
+        const script =
+          '"{\\n  \\"script\\": {\\n    \\"source\\": \\"return true;\\",\\n    \\"params\\": {\\n  \\"string_parameter\\": \\"string value\\",\\n  \\"number_parameter\\": 1.5,\\n  \\"boolean_parameter\\": true\\n}\\n  }\\n}"';
+
+        const { body } = await supertest
+          .post(`${API_BASE_PATH}/execute`)
+          .set(svlCommonApi.getInternalRequestHeader())
+          .set('Content-Type', 'application/json;charset=UTF-8')
+          .send(script)
+          .expect(200);
+
+        expect(body).to.eql({
+          result: 'true',
+        });
+      });
+
+      it('should return error response for invalid painless script', async () => {
+        const invalidScript =
+          '"{\\n  \\"script\\": {\\n    \\"source\\": \\"foobar\\",\\n    \\"params\\": {\\n  \\"string_parameter\\": \\"string value\\",\\n  \\"number_parameter\\": 1.5,\\n  \\"boolean_parameter\\": true\\n}\\n  }\\n}"';
+
+        const { body } = await supertest
+          .post(`${API_BASE_PATH}/execute`)
+          .set(svlCommonApi.getInternalRequestHeader())
+          .set('Content-Type', 'application/json;charset=UTF-8')
+          .send(invalidScript)
+          .expect(200);
+
+        expect(body.error).to.not.be(undefined);
+        expect(body.error.reason).to.eql('compile error');
+      });
+    });
+  });
+}

x-pack/test_serverless/api_integration/test_suites/observability/common_configs/config.group1.ts

@@ -26,6 +26,7 @@ export default async function ({ readConfigFile }: FtrConfigProviderContext) {
       require.resolve('../../common/search_xpack'),
       require.resolve('../../common/core'),
       require.resolve('../../common/reporting'),
+      require.resolve('../../common/painless_lab'),
     ],
     junit: {
       reportName: 'Serverless Observability API Integration Tests - Common Group 1',

x-pack/test_serverless/api_integration/test_suites/security/common_configs/config.group1.ts

@@ -26,6 +26,7 @@ export default async function ({ readConfigFile }: FtrConfigProviderContext) {
       require.resolve('../../common/search_xpack'),
       require.resolve('../../common/core'),
       require.resolve('../../common/reporting'),
+      require.resolve('../../common/painless_lab'),
     ],
     junit: {
       reportName: 'Serverless Security API Integration Tests - Common Group 1',