test(operator): Add comprehensive unit tests for trustee module

[6-dehan]

This commit introduces a full suite of 15 unit tests for the functions within trustee.rs, validating pure logic, error handling, and both simple and complex Kubernetes API interactions using a mocked client.

• test_get_image_pcrs_success: Verifies that a valid JSON string in a ConfigMap is correctly deserialized into the ImagePcrs struct.
• test_get_image_pcrs_no_data: Ensures an error is returned when the ConfigMap's data field is missing.
• test_get_image_pcrs_invalid_json: Confirms that an error is propagated when the data contains an invalid JSON string.
• test_generate_luks_key_returns_correct_size: A sanity check to validate that generate_luks_key runs without errors and returns a key of the expected 32-byte length.

These tests validate the idempotency and error handling of functions that perform a single create operation, primarily testing the info_if_exists! macro.

• test_create_rv_config_map_success: Verifies the function returns Ok(()) on a successful API response (200 OK).
• test_create_rv_config_map_already_exists: Verifies the function correctly handles a 409 Conflict and returns Ok(()), confirming idempotency.
• test_create_rv_config_map_generic_error: Ensures a generic API error (e.g., 500) is properly propagated as an Err.
• test_generate_resource_policy_success: Validates the success path for the generate_resource_policy function.
• test_generate_kbs_https_certificate_success: Validates the success path for the generate_kbs_https_certificate function.
• test_generate_kbs_configurations_success: Validates the success path for the generate_kbs_configurations function.
• test_generate_attestation_policy_success: Validates the success path for the generate_attestation_policy function.
• test_generate_kbs_success: Validates the success path for the generate_kbs function.

These tests use a stateful mock client to simulate entire operational flows involving multiple API calls.

• test_recompute_reference_values_flow: Verifies the complete GET (PCRs) -> GET (RV map) -> PUT (RV map) sequence executes successfully.
• test_generate_secret_flow_success: Validates the full CREATE (Secret) -> GET (KbsConfig) -> PATCH (KbsConfig) workflow for adding a new secret.
• test_generate_secret_already_present_in_spec: Tests the boundary condition where a secret ID already exists in the KbsConfig spec, ensuring the function exits early without making a redundant PATCH call.

[6-dehan]

$ cargo test -p operator
Finished test profile [unoptimized + debuginfo] target(s) in 0.39s
Running unittests src/main.rs (target/debug/deps/operator-eefd1bab08fd6337)

running 15 tests
test trustee::tests::test_generate_attestation_policy_success ... ok
test trustee::tests::test_create_rv_config_map_success ... ok
test trustee::tests::test_create_rv_config_map_generic_error ... ok
test trustee::tests::test_create_rv_config_map_already_exists ... ok
test trustee::tests::test_generate_kbs_https_certificate_success ... ok
test trustee::tests::test_generate_kbs_success ... ok
test trustee::tests::test_generate_kbs_configurations_success ... ok
test trustee::tests::test_get_image_pcrs_invalid_json ... ok
test trustee::tests::test_get_image_pcrs_no_data ... ok
test trustee::tests::test_get_image_pcrs_success ... ok
test trustee::tests::test_generate_resource_policy_success ... ok
test trustee::tests::test_recompute_reference_values_flow ... ok
test trustee::tests::test_generate_luks_key_returns_correct_size ... ok
test trustee::tests::test_generate_secret_already_present_in_spec ... ok
test trustee::tests::test_generate_secret_flow_success ... ok

test result: ok. 15 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s

Some changes are applied, some are not, and I will continue to update.

[Jakob-Naucke]

Thanks for your updates. Please ensure that the CI passes, e.g. formatting your code using cargo fmt.

[Jakob-Naucke]

This PR version has some of the merged changes restored, but not all of them (e.g. this older piece is still there). I don't think this PR needs to change most of what's above the tests module, just the Deserialize derive (I could be missing something that is required though).

[Jakob-Naucke]

There are a lot of changes in the PR that are formatting only (e.g. this one), but the code was already formatted right, which is why the format CI is failing. Please use cargo fmt with a recent version (1.85+) and default config.

[alicefr]

This PR has been superseded by #53