async function getAccessToken()

in Composer/packages/client/src/utils/authClient.ts [26:92]
56 lines of code
18 McCabe index (conditional complexity)

async function getAccessToken(options: AuthParameters): Promise<string> {
  const { targetResource = '', scopes = [] } = options;
  try {
    if (isElectron()) {
      const { __csrf__ = '' } = window;

      let url = '/api/auth/getAccessToken?';
      const params = new URLSearchParams();
      if (targetResource) {
        params.append('targetResource', targetResource);
      }
      url += params.toString();
      const result = await fetch(url, { method: 'GET', headers: { 'X-CSRF-Token': __csrf__ } });
      const { accessToken = '' } = await result.json();
      return accessToken;
    } else if (authConfig.clientId && authConfig.redirectUrl && authConfig.tenantId) {
      // get access token from cache
      const key = authConfig.clientId + JSON.stringify(scopes);
      let token = getTokenFromCache(key);
      if (token && !isTokenExpired(token)) {
        return token;
      }

      // get id token
      if (!idToken) {
        // pop up window if token not exist
        const popup = createPopupWindow(
          getIdTokenUrl({ clientId: authConfig.clientId, redirectUrl: authConfig.redirectUrl })
        );
        if (popup) {
          idToken = await monitorWindowForQueryParam(popup, 'id_token', authConfig.redirectUrl);
          storage.set('idToken', idToken || '');
        }
      } else if (isTokenExpired(idToken)) {
        // refresh idToken
        const notDisplayFrame = createHiddenIframe(
          getIdTokenUrl({ clientId: authConfig.clientId, redirectUrl: authConfig.redirectUrl })
        );
        idToken =
          notDisplayFrame.contentWindow &&
          (await monitorWindowForQueryParam(notDisplayFrame.contentWindow, 'id_token', authConfig.redirectUrl));
        storage.set('idToken', idToken || '');
      }

      // use id token to get access token
      if (typeof idToken === 'string') {
        const notDisplayFrame = createHiddenIframe(
          getAccessTokenUrl({ clientId: authConfig.clientId, redirectUrl: authConfig.redirectUrl, scopes: scopes })
        );
        token =
          notDisplayFrame.contentWindow &&
          (await monitorWindowForQueryParam(notDisplayFrame.contentWindow, 'access_token', authConfig.redirectUrl));
        notDisplayFrame.remove();
        // update cache
        storage.set(key, token);
        return token || '';
      }

      return '';
    }
    return '';
  } catch (e) {
    // error handling
    console.error('Did not receive an access token back from the server: ', e);
    return '';
  }
}