Use same version of Bazel that is executing the test

[jfirebaugh]

rules_bazel_integration_test might be used in a scenario where there's already scaffolding in place to run tests under different versions of Bazel. For example, with Bazel's own CI this might be configured as a test matrix where different rows of the matrix use a specific Bazel version. This could be used to execute an entire test suite, containing both unit and integration tests, with the same Bazel version.

Because this scaffolding would exist at a level higher than rules_bazel_integration_test, it would be desirable to configure rules_bazel_integration_test to simply use the same bazel binary that's executing the top-level bazel test command, rather than configuring an explicit binary via bazel_version or bazel_binary.

Is this something that could be supported?

[cgrindel]

This is an interesting idea. What feature(s) from rules_bazel_integration_test would be useful in this situation? My mental model for rules_bazel_integration_test is that it provides a means for testing a Bazel ruleset from bootstrap through build/test from within the ruleset workspace. If there is an external system providing the matrix inputs, they could just run Bazel directly in the child workspace.