Function waitForPattern

extensions/cli/src/test-helpers/cli-helpers.ts:212–240

(
  proc: Subprocess,
  pattern: RegExp | string,
  timeout: number = 5000,
)

 * Waits for a pattern in the output
 */
export function waitForPattern(
  proc: Subprocess,
  pattern: RegExp | string,
  timeout: number = 5000,
): Promise<string> {
  return new Promise((resolve, reject) => {
    let output = "";
    const timer = setTimeout(() => {
      proc.kill();
      reject(new Error(`Timeout waiting for pattern: ${pattern}`));
    }, timeout);

    const checkOutput = (data: string) => {
      output += data;
      const match =
        typeof pattern === "string"
          ? output.includes(pattern)
          : pattern.test(output);

      if (match) {
        clearTimeout(timer);
        resolve(output);
      }
    };

    proc.stdout?.on("data", checkOutput);
    proc.stderr?.on("data", checkOutput);
  });
}

/**
 * Simulates user input in interactive mode