test: deploymentinfo.cpp unit tests #25219

This patch implements the unit tests for deploymentinfo.h and deploymentinfo.cpp. These changes will improve test coverage and run within the unit test suite.

Test coverage: https://marcofalke.github.io/btc_cov/test_bitcoin.coverage/src/deploymentinfo.h.gcov.html https://marcofalke.github.io/btc_cov/test_bitcoin.coverage/src/deploymentinfo.cpp.gcov.html

Test execution excerpt:

test/deploymentinfo_tests.cpp(10): Entering test suite "deploymentinfo_tests"
test/deploymentinfo_tests.cpp(12): Entering test case "name_from_pos"
test/deploymentinfo_tests.cpp(15): info: check DeploymentName(Consensus::DEPLOYMENT_TESTDUMMY) == VersionBitsDeploymentInfo[Consensus::DEPLOYMENT_TESTDUMMY].name has passed
test/deploymentinfo_tests.cpp(16): info: check DeploymentName(Consensus::DEPLOYMENT_TAPROOT) == VersionBitsDeploymentInfo[Consensus::DEPLOYMENT_TAPROOT].name has passed
test/deploymentinfo_tests.cpp(12): Leaving test case "name_from_pos"; testing time: 7564us
test/deploymentinfo_tests.cpp(19): Entering test case "name_from_dep"
test/deploymentinfo_tests.cpp(22): info: check DeploymentName(Consensus::DEPLOYMENT_HEIGHTINCB) == "bip34" has passed
test/deploymentinfo_tests.cpp(23): info: check DeploymentName(Consensus::DEPLOYMENT_CLTV) == "bip65" has passed
test/deploymentinfo_tests.cpp(24): info: check DeploymentName(Consensus::DEPLOYMENT_DERSIG) == "bip66" has passed
test/deploymentinfo_tests.cpp(25): info: check DeploymentName(Consensus::DEPLOYMENT_CSV) == "csv" has passed
test/deploymentinfo_tests.cpp(26): info: check DeploymentName(Consensus::DEPLOYMENT_SEGWIT) == "segwit" has passed
test/deploymentinfo_tests.cpp(19): Leaving test case "name_from_dep"; testing time: 2011us
test/deploymentinfo_tests.cpp(10): Leaving test suite "deploymentinfo_tests"; testing time: 9707us

Not sure if this is worth it. We already have a test to check the name in the functional tests, see https://marcofalke.github.io/btc_cov/total.coverage/src/deploymentinfo.cpp.gcov.html

Test coverage is nice, but shouldn't be a goal in itself. The goal should be to avoid bugs reaching end users.

Thanks for your first contribution!

Not sure if this is worth

At least these are very small and quick to run tests!

But I have to agree that I'm not sure it adds useful testing. Checking the content of a static mapping against its expected values creates an extra place where changes need to be made, but I'm not sure it'd find bugs.

Thank you for your contribution, but I am closing for now. It seems unlikely that someone changes the consensus deployments but everyone forgets to check the name returned via RPC. Not to mention the functional test that already checks the same thing. It seems more likely that this will add maintenance burden in the future.