Add scenario recorder

This adds a new class which will setup the MSW server to record requests,
save them to memory and save them to files when calling a separate save
method.

extensions/ql-vscode/src/mocks/recorder.ts

@@ -0,0 +1,176 @@
+import * as fs from 'fs-extra';
+import * as path from 'path';
+
+import { MockedRequest } from 'msw';
+import { SetupServerApi } from 'msw/node';
+import { IsomorphicResponse } from '@mswjs/interceptors';
+
+import { DisposableObject } from '../pure/disposable-object';
+
+import { GitHubApiRequest, RequestKind } from './gh-api-request';
+
+export class Recorder extends DisposableObject {
+  private readonly allRequests = new Map<string, MockedRequest>();
+  private currentRecordedScenario: GitHubApiRequest[] = [];
+
+  private _recording = false;
+
+  constructor(
+    private readonly server: SetupServerApi,
+  ) {
+    super();
+    this.onRequestStart = this.onRequestStart.bind(this);
+    this.onResponseBypass = this.onResponseBypass.bind(this);
+  }
+
+  public get isRecording(): boolean {
+    return this._recording;
+  }
+
+  public get scenarioRequestCount(): number {
+    return this.currentRecordedScenario.length;
+  }
+
+  public start(): void {
+    if (this._recording) {
+      return;
+    }
+
+    this._recording = true;
+
+    this.clear();
+
+    this.server.events.on('request:start', this.onRequestStart);
+    this.server.events.on('response:bypass', this.onResponseBypass);
+  }
+
+  public stop(): void {
+    if (!this._recording) {
+      return;
+    }
+
+    this._recording = false;
+
+    this.server.events.removeListener('request:start', this.onRequestStart);
+    this.server.events.removeListener('response:bypass', this.onResponseBypass);
+  }
+
+  public clear() {
+    this.currentRecordedScenario = [];
+    this.allRequests.clear();
+  }
+
+  public async save(scenariosDirectory: string, name: string): Promise<string> {
+    const scenarioDirectory = path.join(scenariosDirectory, name);
+
+    await fs.ensureDir(scenarioDirectory);
+
+    for (let i = 0; i < this.currentRecordedScenario.length; i++) {
+      const request = this.currentRecordedScenario[i];
+
+      const fileName = `${i}-${request.request.kind}.json`;
+      const filePath = path.join(scenarioDirectory, fileName);
+      await fs.writeFile(filePath, JSON.stringify(request, null, 2));
+    }
+
+    this.stop();
+
+    return scenarioDirectory;
+  }
+
+  private onRequestStart(request: MockedRequest): void {
+    this.allRequests.set(request.id, request);
+  }
+
+  private onResponseBypass(response: IsomorphicResponse, requestId: string): void {
+    const request = this.allRequests.get(requestId);
+    this.allRequests.delete(requestId);
+    if (!request) {
+      return;
+    }
+
+    if (response.body === undefined) {
+      return;
+    }
+
+    const gitHubApiRequest = createGitHubApiRequest(request.url.toString(), response.status, response.body);
+    if (!gitHubApiRequest) {
+      return;
+    }
+
+    this.currentRecordedScenario.push(gitHubApiRequest);
+  }
+}
+
+function createGitHubApiRequest(url: string, status: number, body: string): GitHubApiRequest | undefined {
+  if (!url) {
+    return undefined;
+  }
+
+  if (url.match(/\/repos\/[a-zA-Z0-9-_.]+\/[a-zA-Z0-9-_.]+$/)) {
+    return {
+      request: {
+        kind: RequestKind.GetRepo,
+      },
+      response: {
+        status,
+        body: JSON.parse(body),
+      },
+    };
+  }
+
+  if (url.match(/\/repositories\/\d+\/code-scanning\/codeql\/variant-analyses$/)) {
+    return {
+      request: {
+        kind: RequestKind.SubmitVariantAnalysis,
+      },
+      response: {
+        status,
+        body: JSON.parse(body),
+      },
+    };
+  }
+
+  if (url.match(/\/repositories\/\d+\/code-scanning\/codeql\/variant-analyses\/\d+$/)) {
+    return {
+      request: {
+        kind: RequestKind.GetVariantAnalysis,
+      },
+      response: {
+        status,
+        body: JSON.parse(body),
+      },
+    };
+  }
+
+  const repoTaskMatch = url.match(/\/repositories\/\d+\/code-scanning\/codeql\/variant-analyses\/\d+\/repositories\/(?<repositoryId>\d+)$/);
+  if (repoTaskMatch?.groups?.repositoryId) {
+    return {
+      request: {
+        kind: RequestKind.GetVariantAnalysisRepo,
+        repositoryId: parseInt(repoTaskMatch.groups.repositoryId, 10),
+      },
+      response: {
+        status,
+        body: JSON.parse(body),
+      },
+    };
+  }
+
+  // if url is a download URL for a variant analysis result, then it's a get-variant-analysis-repoResult.
+  const repoDownloadMatch = url.match(/objects-origin\.githubusercontent\.com\/codeql-query-console\/codeql-variant-analysis-repo-tasks\/\d+\/(?<repositoryId>\d+)/);
+  if (repoDownloadMatch?.groups?.repositoryId) {
+    return {
+      request: {
+        kind: RequestKind.GetVariantAnalysisRepoResult,
+        repositoryId: parseInt(repoDownloadMatch.groups.repositoryId, 10),
+      },
+      response: {
+        status,
+        body: body as unknown as ArrayBuffer,
+      }
+    };
+  }
+
+  return undefined;
+}