fix: Non-determinism in S3PropertySourceTest

[yonghanlin]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

This pull request updates the S3PropertySourceTest.shouldParseDifferentFilesFromBucket test to avoid relying on a non-deterministic ordering of property names.

The test asserted the exact order of the property names:

assertThat(propertySource.getPropertyNames()).containsExactly("key1", "key2");

However, propertySource.getPropertyNames() is derived from a collection whose iteration order is not guaranteed (e.g. Hashtable). With repeated run, the property names can be returned as ["key2", "key1"]. The changes in this pull request use containsExactlyInAnyOrder() to validate the presence of both keys regardless of order:

assertThat(propertySource.getPropertyNames()).containsExactlyInAnyOrder("key1", "key2");

💡 Motivation and Context

When running with NonDex, S3PropertySourceTest.shouldParseDifferentFilesFromBucket was reported as non-deterministic. NonDex is a tool for detecting wrong assumptions on under-determined Java APIs. By relaxing the assertion in the test to be order-independent, we preserve the original intent of the test and eliminating nondeterministic behavior. This improves test reliability in continuous integration environments.

💚 How did you test it?

Run NonDex on spring-cloud-aws-s3 module using the following command:

mvn -pl spring-cloud-aws-s3 edu.illinois:nondex-maven-plugin:2.1.7:nondex -Dtest=io.awspring.cloud.s3.config.S3PropertySourceTest#shouldParseDifferentFilesFromBucket 

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• I updated reference documentation to reflect the change
• All tests passing
• No breaking changes

🔮 Next steps