[scout] Add Jest events reporter (#214662)

## Summary

Same as for Playwright, this adds a custom Jest reporter that records
and uploads test events.

## Quirks

### Config file path
Jest is not including the path to the config file used to run the tests
in any information passed to the reporter, so this needs to be passed in
the `JEST_CONFIG_PATH` environment variable. If Jest is invoked with the
`scripts/jest.js` script, the `JEST_CONFIG_PATH` environment variable
will be populated with the correct value automatically.

### All the events are produced when the run has completed
This is different from the other reporters because the custom reporter
interface in Jest is giving the reporter access to necessary info at
init or when the run starts. The earliest we can start producing the
Scout events is, unfortunately, only after the test run has completed.

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Cesare de Cal <cesare.decal@elastic.co>

src/platform/packages/private/kbn-scout-reporting/src/reporting/jest/index.js

@@ -0,0 +1,11 @@
+/*
+ * 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", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+require('@kbn/babel-register').install();
+module.exports = require('./reporter').ScoutJestReporter;

src/platform/packages/private/kbn-scout-reporting/src/reporting/jest/options.ts

@@ -0,0 +1,20 @@
+/*
+ * 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", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+import { ScoutTestRunConfigCategory } from '@kbn/scout-info';
+
+/**
+ * Configuration options for the Scout Jest reporter
+ */
+export interface ScoutJestReporterOptions {
+  name?: string;
+  runId?: string;
+  configCategory?: ScoutTestRunConfigCategory;
+  outputPath?: string;
+}

src/platform/packages/private/kbn-scout-reporting/src/reporting/jest/reporter.ts

@@ -0,0 +1,247 @@
+/*
+ * 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", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+import { Config, AggregatedResult, TestContext, ReporterOnStartOptions } from '@jest/reporters';
+import { BaseReporter } from '@jest/reporters';
+import { TestResult } from '@jest/types';
+import { ToolingLog } from '@kbn/tooling-log';
+import {
+  type CodeOwnerArea,
+  CodeOwnersEntry,
+  findAreaForCodeOwner,
+  getCodeOwnersEntries,
+  getOwningTeamsForPath,
+} from '@kbn/code-owners';
+import { SCOUT_REPORT_OUTPUT_ROOT } from '@kbn/scout-info';
+import path from 'node:path';
+import { REPO_ROOT } from '@kbn/repo-info';
+import stripAnsi from 'strip-ansi';
+import { ScoutJestReporterOptions } from './options';
+import {
+  datasources,
+  generateTestRunId,
+  getTestIDForTitle,
+  ScoutEventsReport,
+  ScoutFileInfo,
+  ScoutReportEventAction,
+  type ScoutTestRunInfo,
+  uploadScoutReportEvents,
+} from '../../..';
+
+/**
+ * Scout Jest reporter
+ */
+export class ScoutJestReporter extends BaseReporter {
+  name: string;
+  readonly scoutLog: ToolingLog;
+  readonly runId: string;
+  private report: ScoutEventsReport;
+  private baseTestRunInfo: ScoutTestRunInfo;
+  private readonly codeOwnersEntries: CodeOwnersEntry[];
+
+  constructor(
+    _jestGlobalConfig: Config.GlobalConfig,
+    private reporterOptions: ScoutJestReporterOptions
+  ) {
+    super();
+    this.scoutLog = new ToolingLog({
+      level: 'info',
+      writeTo: process.stdout,
+    });
+
+    this.name = this.reporterOptions.name || 'unknown';
+    this.runId = this.reporterOptions.runId || generateTestRunId();
+    this.scoutLog.info(`Scout test run ID: ${this.runId}`);
+
+    this.report = new ScoutEventsReport(this.scoutLog);
+    this.baseTestRunInfo = {
+      id: this.runId,
+      config: {
+        category: reporterOptions.configCategory,
+      },
+    };
+
+    this.codeOwnersEntries = getCodeOwnersEntries();
+  }
+
+  private getFileOwners(filePath: string): string[] {
+    return getOwningTeamsForPath(filePath, this.codeOwnersEntries);
+  }
+
+  private getOwnerAreas(owners: string[]): CodeOwnerArea[] {
+    return owners
+      .map((owner) => findAreaForCodeOwner(owner))
+      .filter((area) => area !== undefined) as CodeOwnerArea[];
+  }
+
+  private getScoutFileInfoForPath(filePath: string): ScoutFileInfo {
+    const fileOwners = this.getFileOwners(filePath);
+
+    return {
+      path: filePath,
+      owner: fileOwners,
+      area: this.getOwnerAreas(fileOwners),
+    };
+  }
+
+  /**
+   * Root path of this reporter's output
+   */
+  public get reportRootPath(): string {
+    const outputPath = this.reporterOptions.outputPath || SCOUT_REPORT_OUTPUT_ROOT;
+    return path.join(outputPath, `scout-jest-${this.runId}`);
+  }
+
+  /**
+   * Separate the error message from the stack trace in a Jest failure message
+   *
+   * If the message doesn't contain a stack trace, it'll return unmodified.
+   *
+   * @param message Jest failure message
+   */
+  parseJestFailureMessage(message: string) {
+    const match = message.match(/(?<message>^.+?)(\r\n|\r|\n)(?=.+?at)\s(?<stack_trace>.+$)/s);
+
+    return match === null
+      ? { message }
+      : (match.groups as { message: string; stack_trace?: string });
+  }
+
+  /**
+   * Log a Jest test result as a Scout reporter event
+   *
+   * @param test Jest test information
+   * @param test.result Jest test result
+   * @param test.filePath Jest test file path
+   *
+   */
+  logTestResult(test: { result: TestResult.AssertionResult; filePath: string }): void {
+    const suiteTitle = test.result.ancestorTitles.join(' ');
+    const parsedErrorMessages: string[] = [];
+    const parsedStackTraces: string[] = [];
+
+    test.result.failureMessages
+      .map((message) => this.parseJestFailureMessage(stripAnsi(message)))
+      .forEach((parsed) => {
+        if (parsed.message) {
+          parsedErrorMessages.push(parsed.message);
+        }
+        if (parsed.stack_trace) {
+          parsedStackTraces.push(parsed.stack_trace);
+        }
+      });
+
+    this.report.logEvent({
+      ...datasources.environmentMetadata,
+      reporter: {
+        name: this.name,
+        type: 'jest',
+      },
+      test_run: this.baseTestRunInfo,
+      suite: {
+        title: suiteTitle || 'unknown',
+        type: test.result.ancestorTitles.length <= 1 ? 'root' : 'suite',
+      },
+      test: {
+        id: getTestIDForTitle(test.result.fullName),
+        title: test.result.title,
+        tags: [],
+        file: this.getScoutFileInfoForPath(path.relative(REPO_ROOT, test.filePath)),
+        status: test.result.status === 'pending' ? 'skipped' : test.result.status,
+        duration: test.result.duration || 0,
+      },
+      event: {
+        action: ScoutReportEventAction.TEST_END,
+        error: {
+          message:
+            parsedErrorMessages.length > 0
+              ? parsedErrorMessages.join('\n--- NEXT ERROR ---\n')
+              : undefined,
+          stack_trace:
+            parsedStackTraces.length > 0
+              ? parsedStackTraces.join('\n--- NEXT STACK TRACE ---\n')
+              : undefined,
+        },
+      },
+    });
+  }
+
+  onRunStart(results: AggregatedResult, _options?: ReporterOnStartOptions): void {
+    /**
+     * Test execution started
+     */
+    // Look for Jest config path in environment variables
+    // Must do it here rather than the constructor as the reporter object is created when the Jest config is evaluated
+    // and the JEST_CONFIG_PATH environment variable might not be set
+    this.baseTestRunInfo = {
+      ...this.baseTestRunInfo,
+      config: {
+        ...this.baseTestRunInfo.config,
+        file:
+          process.env.JEST_CONFIG_PATH !== undefined
+            ? this.getScoutFileInfoForPath(path.relative(REPO_ROOT, process.env.JEST_CONFIG_PATH))
+            : undefined,
+      },
+    };
+
+    // Log "run start" event
+    this.report.logEvent({
+      ...datasources.environmentMetadata,
+      '@timestamp': new Date(results.startTime),
+      reporter: {
+        name: this.name,
+        type: 'jest',
+      },
+      test_run: this.baseTestRunInfo,
+      event: {
+        action: ScoutReportEventAction.RUN_BEGIN,
+      },
+    });
+  }
+
+  async onRunComplete(_testContexts: Set<TestContext>, results: AggregatedResult): Promise<void> {
+    /**
+     * Test execution ended
+     */
+    // Turn test results into events in bulk
+    results.testResults.forEach((suite) => {
+      suite.testResults.forEach((testResult) => {
+        this.logTestResult({ result: testResult, filePath: suite.testFilePath });
+      });
+    });
+
+    // Log "run end" event
+    this.report.logEvent({
+      ...datasources.environmentMetadata,
+      reporter: {
+        name: this.name,
+        type: 'jest',
+      },
+      test_run: {
+        ...this.baseTestRunInfo,
+        status: results.numFailedTests === 0 ? 'passed' : 'failed',
+        duration: Date.now() - results.startTime || 0,
+      },
+      event: {
+        action: ScoutReportEventAction.RUN_END,
+      },
+    });
+
+    // Save & conclude the report
+    try {
+      this.report.save(this.reportRootPath);
+      await uploadScoutReportEvents(this.report.eventLogPath, this.scoutLog);
+    } catch (e) {
+      // Log the error but don't propagate it
+      this.scoutLog.error(e);
+    } finally {
+      this.report.conclude();
+    }
+  }
+}

src/platform/packages/shared/kbn-test/jest-preset.js

@@ -52,6 +52,14 @@ module.exports = {
           ],
         ]
       : []),
+    ...(['1', 'yes', 'true'].includes(process.env.SCOUT_REPORTER_ENABLED)
+      ? [
+          [
+            '<rootDir>/src/platform/packages/private/kbn-scout-reporting/src/reporting/jest',
+            { name: 'Jest tests (unit)', configCategory: 'unit-test' },
+          ],
+        ]
+      : []),
   ],
 
   // The paths to modules that run some code to configure or set up the testing environment before each test

src/platform/packages/shared/kbn-test/jest_integration/jest-preset.js

@@ -39,6 +39,14 @@ module.exports = {
           ],
         ]
       : []),
+    ...(['1', 'yes', 'true'].includes(process.env.SCOUT_REPORTER_ENABLED)
+      ? [
+          [
+            '<rootDir>/src/platform/packages/private/kbn-scout-reporting/src/reporting/jest',
+            { name: 'Jest tests (integration)', configCategory: 'unit-integration-test' },
+          ],
+        ]
+      : []),
   ],
   coverageReporters: !!process.env.CI
     ? [['json', { file: 'jest-integration.json' }]]

src/platform/packages/shared/kbn-test/jest_integration_node/jest-preset.js

@@ -46,6 +46,14 @@ module.exports = {
         testGroupType: 'Jest Integration Tests',
       },
     ],
+    ...(['1', 'yes', 'true'].includes(process.env.SCOUT_REPORTER_ENABLED)
+      ? [
+          [
+            '<rootDir>/src/platform/packages/private/kbn-scout-reporting/src/reporting/jest',
+            { name: 'Jest tests (integration, node)', configCategory: 'unit-integration-test' },
+          ],
+        ]
+      : []),
   ],
   coverageReporters: !!process.env.CI
     ? [['json', { file: 'jest-integration.json' }]]

src/platform/packages/shared/kbn-test/src/jest/run.ts

@@ -27,6 +27,7 @@ import { createFailError } from '@kbn/dev-cli-errors';
 import { REPO_ROOT } from '@kbn/repo-info';
 import { map } from 'lodash';
 import getopts from 'getopts';
+import { SCOUT_REPORTER_ENABLED } from '@kbn/scout-info';
 import jestFlags from './jest_flags.json';
 
 // yarn test:jest src/core/server/saved_objects
@@ -144,12 +145,22 @@ export function runJest(configName = 'jest.config.js') {
     }
 
     log.info('yarn jest', process.argv.slice(2).join(' '));
+
+    if (SCOUT_REPORTER_ENABLED) {
+      // Expose Jest config file path via environment variables
+      process.env.JEST_CONFIG_PATH = configPath;
+    }
   }
 
   if (process.env.NODE_ENV == null) {
     process.env.NODE_ENV = 'test';
   }
 
+  if (SCOUT_REPORTER_ENABLED && argv.config) {
+    // Expose Jest config file path via environment variables
+    process.env.JEST_CONFIG_PATH = argv.config;
+  }
+
   run().then(() => {
     // Success means that tests finished, doesn't mean they passed.
     reportTime(runStartTime, 'total', {