Prevent unit tests from trying to acquire Application Default Credentials

A number of unit tests trigger autoconfiguration of DefaultCredentialsProvider. The symptom of it is “java.io.IOException: The Application Default Credentials are not available” output, plus the test takes longer than it should (because interacting with file system is relatively expensive).

1. In an environment that does not have ADC, run mvn test, which will run unit tests only, and inventory all tests that complain about credentials. Hint: you can cheat here and take any JUnit output from GitHubActions, as credentials are unavailable there.
2. Pick a test from your list. Figure out what needs to be done in test setup to override credentials, so that autoconfigured DefaultCredentialsProvider is never instantiated. Hint: it’s going to be a matter of either making a @Bean of type CredentialsProvider available in test configuration, or in using .withBean() to do the same in programmatically generated context. There are examples of both in the codebase. Some instances use a mock(CredentialsProvider.class), while others return a new credentials provider as a lambda () -> NoCredentialsProvider.create().

Bonus: measure how long all unit tests take to run before you start making changes, and measure the same after all changes are done. How much faster have our unit tests gotten?

[elefeint]

@Mowee please open a new issue describing what you are trying to achieve. This issue was for an internal test infrastructure, which should not affect you unless you are working on Spring Cloud GCP project.

[Mowee]

@elefeint Thank you, I will do.