fix: align tx evaluate fixtures with Conway-only platform behavior

[ginnun]

Fixture Changes for Conway-only Deserialization

Background

blockfrost-platform uses pallas decoding and testgen-hs with cardano-ledger's Conway decoder both. Both decodes only conway.

Rust's pallas produces different error strings than Haskell's cardano-ledger for the same invalid CBOR input.

The test CBOR in txs-evaluate-utxos contains an empty required_signers field (CBOR key 14 = 0x80). Conway's fieldGuarded validation rejects empty sets that are present rather than omitted. Ogmios avoids this via Babbage fallback, so the transaction never reaches evaluation. Platform behavior depends on which decoder is in use.

Below brief explanation of what tests did change:

Preview (src/fixtures/preview/utils/)

txs-evaluate.ts

fails (client fault) to submit on ill-formed tx

• Old: exact string match '...DeserialiseFailure 0 "expected tag".'
• New: stringContaining('...CBOR failed with error:')
• Reason: Pallas (Rust) and cardano-ledger (Haskell) produce different error suffixes for the same malformed CBOR. We now match only the shared prefix.

txs-evaluate-utxos.ts

error Unknown transaction input (missing from UTxO set)

• Old: static response object asserting a single jsonwsp/response with nested EvaluationFailure.ScriptFailures
• New: customExpect function that handles two possible outcomes:
  • jsonwsp/response path: asserts exact error string including tx input hash via .toBe('Unknown transaction input (missing from UTxO set): 7d67...eb6b#0')
  • jsonwsp/fault path: asserts response.fault.string contains 'Required Signer Hashes'
• Reason: Conway's fieldGuarded rejects the empty required_signers set before evaluation, returning a jsonwsp/fault. Ogmios decodes via Babbage and reaches evaluation, returning a jsonwsp/response. The test now accepts both paths depending on the platform's decoder.

---

Preprod (src/fixtures/preprod/utils/)

txs-evaluate.ts

Same change as preview txs-evaluate.ts.

txs-evaluate-utxos.ts

Same change as preview txs-evaluate-utxos.ts.

[michalrus]

But won’t this break other places that blockfrost-tests are used in? 👀

[vladimirvolek]

But won’t this break other places that blockfrost-tests are used in? 👀

https://github.com/blockfrost/blockfrost-tests-internal/actions/runs/24073289428

[ginnun]

Yes, it will break of course.
I am trying to mimic the existing behaviour of ogmios + our Blockfrost API.
There are cases that it's too much hack to mimic, so I am considering loosening the tests (like partially matching error strings) or accepting two different responses. I will update here once done with it. @vladimirvolek @michalrus