Method postMessage

vscode/src/webview/createVscodeOrpcLink.test.ts:16–22

(payload: WebviewToExtensionMessage)

  private readonly listeners = new Set<(data: unknown) => void>();

  postMessage(payload: WebviewToExtensionMessage): void {
    this.sent.push(payload);

    if (this.throwOnPostMessage) {
      throw new Error("postMessage failed");
    }
  }

  onMessage(handler: (data: unknown) => void): () => void {
    this.listeners.add(handler);