Option to delay test execution in watch mode

[novemberborn]

Prompted by @jakobrosenberg, I'd like to explore options to delay test execution in watch mode. Specifically for use cases where tests are run against build output, and the build process takes a while to settle down.

@jakobrosenberg you mentioned Rollup's buildDelay, but also suggested a diskIdle option. Is that something you've seen elsewhere? How would you characterize the differences?

[jakobrosenberg]

How would you characterize the differences?

I think I misphrased "better option". I really meant a better name (compared to delay, which can be very ambiguous). diskIdle on the other hand reminds me of window.requestIdleCallback, which I find self explanatory.

[novemberborn]

By "idle" you mean "this much time has passed since we last observed a file change"?

[jakobrosenberg]

Correct. It's a slight misnomer. 😳

[novemberborn]

No worries. See #2715 for the issue.