Speed up directory monitoring tests

[snprajwal]

Summary

The directory monitoring tests check for whether the documentation is rebuilt if the documentation catalog is edited when running a live server with docc preview. These tests assumed an extremely generous timeout of 5 seconds for changes to the directory, and 10 seconds for a lack of change. Thus, they ran much slower than the rest of the test suite. The timeouts have been reduced to a more reasonable threshold of 1.5 seconds, which still succeeds with throttled CPU resources.

Dependencies

N/A

Testing

This was tested by restricting CPU resources to 20% of a single core and running the tests 100 times:

for i in $(seq 1 100); do cpulimit -i -l 20 swift test --filter DirectoryMonitor; done

Checklist

Make sure you check off the following items. If they cannot be completed, provide a reason.

• [ ] Added tests
• Ran the ./bin/test script and it succeeded
• [ ] Updated documentation if necessary

[snprajwal]

@swift-ci please test

[d-ronnqvist]

Only one of these changes make the directory monitor test faster, the rest only make them more fragile without running faster.

[snprajwal]

@swift-ci please test

[snprajwal]

@swift-ci please test