We have new APIs with very good test coverage, but on the whole we haven't done a great job with this. Part of the problem is economics: with hundreds/thousands of blocking bugs, it's hard to justify the cost of spending a lot of time spinning up a test harness for an API with a small state space, that's being tested and hacked on frequently by developers. But as we move forwards and developers start to work on new features, regressions become a constant, increasing cost. And in particular, for big new projects like bug 761935, we have no hope of not Breaking The World without automated testing. A problem with testing some of the new APIs we've created is that writing the /first/ test is often very difficult. Test harnesses rarely fit new uses 100%, so some hard problems have to be solved to clear a path for the first test. After that, additional tests are much easier, since they can usually follow the example of the first. The project of this meta-bug is to "clear the paths" for all the new APIs; solve the problems that block having a first test written for each. After that, we can fill state-space coverage using normal processes, as we go along. For example, using branch coverage metrics. To do this we'll need to audit the new APIs we've added.