How to test API calls (Twitter, Google)

So I've written a bot that uses mostly API calls to the Twitter API and the Google API (http requests).

The bot:

1. generates some random phrases from local data
2. calls google to get a related image
3. posts everything to twitter

If I'd wanted to test this bot automatically what'd be the best approach:

• Integration testing with a fake HTTP backend
• Unit tests for every API call faking some results for the actual HTTP calls
• Other

I'm working in node, in case that's relevant.