GitHub-auth.ts

private async getGitHubToken(scopes: readonly string[]): Promise<[string, string]> {
    return window.withProgress<[string, string]>({
      location: ProgressLocation.Notification,
      title: "Signing in to GitHub...",
      cancellable: true
    }, async (_, token) => {
      const state = uuid();
      const scopeString = scopes.join(' ');
      const authUrl = `${GITHUB_AUTH_URL}` +
        `?client_id=${config.githubClientId}` +
        `&redirect_uri=${encodeURIComponent(CALLBACK_URI)}` +
        `&scope=${encodeURIComponent(scopeString)}` +
        `&state=vscode-${state}`;

      return new Promise<[string, string]>((resolve, reject) => {
        this._pendingStates.set(state, resolve);
        env.openExternal(Uri.parse(authUrl));

        token.onCancellationRequested(() => {
          this._pendingStates.delete(state);
          reject(new Error('User cancelled login'));
        });

        setTimeout(() => {
          this._pendingStates.delete(state);
          reject(new Error('Login timed out'));
        }, 300000);
      });
    });
  }

  private async exchangeCodeForToken(code: string, state: string): Promise<string> {
    const response = await fetch(GITHUB_TOKEN_URL, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Accept': 'application/json'
      },
      body: JSON.stringify({
        client_id: config.githubClientId,
        client_secret: config.githubClientSecret,
        code: code,
        redirect_uri: CALLBACK_URI,
        state: `vscode-${state}`
      })
    });

    const data = await response.json() as GitHubOAuthResponse;
    if (!response.ok || data.error) {
      throw new Error(`Token exchange error: ${data.error || 'Unknown error'}`);
    }

    return data.access_token;
  }

   private async exchangeGitHubTokenForGCPToken(githubToken: string): Promise<TokenResponse> {
    const credential = GithubAuthProvider.credential(githubToken);

    try {
      const result = await signInWithCredential(this.auth, credential);
      const user = result.user;
      const idTokenResult = await user.getIdTokenResult();

      return {
        accessToken: idTokenResult.token,
        refreshToken: user.refreshToken,
        expiresAt: new Date(idTokenResult.expirationTime).getTime()
      };
    } catch (error) {
      this.outputChannel.appendLine(`Error signing in with credential: ${error}`);
      throw error;
    }
  }