fix(trogon_commanded): validate command and aggregate identity configuration in CommandHandlerCase

[yordis]

Summary

• CommandHandlerCase now validates that command and aggregate identity configuration match (field name and prefix) before running assertions
• Catches misconfigurations that previously went undetected: wrong prefix, wrong identifier field, and nil UUID extraction
• Validation only runs when both command and aggregate have identity config — plain struct aggregates (e.g., used with register_transaction_script) skip validation, matching production behavior
• No data transformation — events and state are compared as-is, matching real Commanded runtime behavior where the prefix only affects stream routing

Test plan

• Existing 26 CommandHandlerCase tests pass unchanged (backward compatible)
• New tests: matching config passes, mismatched prefix fails, mismatched field fails, nil UUID extraction fails, assert_error path validates identity
• Trogon command + plain struct aggregate skips validation
• Neither side having identity config works unchanged

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✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/command-handler-case-identity

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[cursor]

PR Summary

Low Risk
Test-support-only changes that add additional assertions and validation; risk is limited to potentially causing previously passing tests to fail when identity configuration is inconsistent.

Overview
CommandHandlerCase now validates command vs aggregate identity configuration (identifier field + identity_prefix) before running assert_events/assert_state/assert_error, and fails fast if the aggregate UUID cannot be extracted via Commanded middleware.

The assertion helpers were refactored to share a run_and_assert/5 wrapper (including clearer failure messages for unexpected success/error paths), and a new ExUnit suite covers matching config, mismatched field/prefix, nil UUID extraction, and backward-compatible behavior when identity config is absent on one or both sides.

^{Written by Cursor Bugbot for commit decfb1c. This will update automatically on new commits. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

[cursor]

One-sided identity config silently bypasses validation

Medium Severity

validate_identity_configuration/2 only validates when both command and aggregate expose identity functions. If only one side is configured, it returns :ok and proceeds. This leaves misconfigured tests passing silently, so CommandHandlerCase can still hide identity mismatches instead of surfacing them.

Additional Locations (1)

• apps/trogon_commanded/test/trogon/commanded/test_support/command_handler_case_identity_test.exs#L150-L160