title: How do I write negative tests for Typescript typings?
body: <p>I have written a few test cases for the Typescript typings of a Javascript project.</p>
  
  <p>The positive tests are simple enough; Just type in a bunch of code, and it should compile. Like this: <a href="https://github.com/geon/reselect/blob/d5b46b80a28b08ceebc1f19e4300630a0dea751a/test/typings/should_compile/index.ts" rel="nofollow noreferrer">https://github.com/geon/reselect/blob/d5b46b80a28b08ceebc1f19e4300630a0dea751a/test/typings/should_compile/index.ts</a></p>
  
  <p>The <em>negative</em> tests are a bit trickier. Some things should <em>not</em> compile, but I can't have multiple tests in the same file anymore, because compilation will fail as long as a single test-case is invalid. So this won't work: <a href="https://github.com/geon/reselect/blob/d5b46b80a28b08ceebc1f19e4300630a0dea751a/test/typings/should_not_compile/index.ts" rel="nofollow noreferrer">https://github.com/geon/reselect/blob/d5b46b80a28b08ceebc1f19e4300630a0dea751a/test/typings/should_not_compile/index.ts</a></p>
  
  <p>How do I ensure the test passes only if all files fail to compile?</p>
  
  <p>The tests should probably be runnable by Travis CI. (With which I have no experience. Sorry.)</p>