test: refactoring test in rpc_generate.py #27878

There was a rpc assertation that only asserted part of the message. The additional untested text (". Make sure the tx has at least one input.") has been added

Line of code that this refactor is testing https://github.com/bitcoin/bitcoin/blob/427853ab49f610e971b73ea4cc1d5366747e52b1/src/rpc/mining.cpp#L350

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According to git blame, this additional text was added in commit 33330778230961cfbf2a24de36b5877e395cc596 in #19836, in several different error messages.

Running git grep "has at least one input" shows that none of them have tests that assert for that specific additional text.

Per git grep "TX decode failed\|Transaction decode failed" test/functional/ if your change were to be done, it might make sense to update the other test assertions at the same time.

OTOH when tests are checking for the existence of the error message, i.e. that the error was raised, and not the exact form of the message, it could be argued that there's little benefit.

According to git blame, this additional text was added in commit 3333077 in #19836, in several different error messages.

Running git grep "has at least one input" shows that none of them have tests that assert for that specific additional text.

Per git grep "TX decode failed\|Transaction decode failed" test/functional/ if your change were to be done, it might make sense to update the other test assertions at the same time.

OTOH when tests are checking for the existence of the error message, i.e. that the error was raised, and not the exact form of the message, it could be argued that there's little benefit.

That's a good point since we already check for the existence of the error I think its best to close this PR