Help Identify Which Partial Tests Based on Changes

[ralphcallaway]

Some orgs have massive test suites that are VERY slow. If I'd like to deploy without running the full suite I can specify which tests classes to run, but figure out which ones will get me to 75% code coverage for everything in my package is nearly impossible without first running the full test suite.

Perhaps the test runner could store data on which tests classes touch which apex classes and triggers along with the percent of the code they cover. With that data we could expose an endpoint we could use with an sfdx plugin to make a best guess at what test classes to use to deploy a specific piece of code.