child
      .stdin
      .as_ref()
      .unwrap()
      .write_all(&self.stdin)
      .unwrap();

    let output = child.wait_with_output().unwrap();

    let stdout = str::from_utf8(&output.stdout).unwrap();
    let stderr = str::from_utf8(&output.stderr).unwrap();
    if output.status.code() != Some(self.expected_exit_code) {
      panic!(
        "Test failed: {}\nstdout:\n{}\nstderr:\n{}",
        output.status, stdout, stderr
      );
    }

    self.expected_stderr.assert_match(stderr);
    self.expected_stdout.assert_match(stdout);

    (self.tempdir, stdout.into())
  }

  pub(crate) fn run_and_extract_file(self, path: impl AsRef<Path>) -> String {
    let tempdir = self.run().0;
    fs::read_to_string(tempdir.path().join(path)).unwrap()
  }

  pub(crate) fn run_and_extract_stdout(self) -> String {
    self.run().1
  }

  pub(crate) fn run_and_deserialize_output<T: DeserializeOwned>(self) -> T {
    let stdout = self.stdout_regex(".*").run_and_extract_stdout();
    serde_json::from_str(&stdout)
      .unwrap_or_else(|err| panic!("Failed to deserialize JSON: {err}\n{stdout}"))