[FR] - Validate transaction without submission

[frog357]

Internal/External
Internal if an IOHK staff member.
External otherwise.

Area
Token Locking Related to Token Locking (Allegra).
Native Tokens Related to Native Tokens (Mary).
Plutus Related to Plutus Scripts (Alonzo).
Other Any other topic (Delegation, Ranking, ...).

Describe the feature you'd like
The ability to validate a transaction before submit. Having a flag that would perform all the same checks as cardano-cli transaction submit but without the submit part.

Additional context / screenshots
Suggestion:
cardano-cli transaction validate --tx-file infile --mainnet

[smelc]

cc @Jimbo4350 @CarlosLopezDeLara

[carbolymer]

We had a short chat with @Jimbo4350 . This may require changes in consensus / ledger first, before we can make changes in cli.

[CarlosLopezDeLara]

Yes, such validation would correspond to the node. In particular, I think would need changes to mempool.

@frog357 Can you tell us more about this FR? What kind of benefits brings or what problems it solves?

[frog357]

I didn’t go into the code to determine the exact requirements, but I was hoping it was modular enough to perform the same validations in the submit routine without actually submitting. In some languages, this is referred to as a "lint" command—the ability to completely validate a transaction’s eligibility to submit without encountering unexpected errors.

Errors like the one included below (for reference) illustrate the kind of issues this could prevent. While I don’t need help with this particular error—I’ve already found the solution—it inspired me to suggest the idea of a "transaction linting" feature. I believe it could improve the ecosystem by offering users a way to preemptively validate transactions.

Unfortunately, I don’t have the capability to create a pull request for this feature myself, but I hope this suggestion resonates with those who are more technically equipped to implement it. It’s a feature people might not realize they need until they encounter scenarios like mine—pushing the limits of transaction size or complexity. For example, when posting a transaction that approaches or exceeds the maximum size, there’s currently no way to know whether it will succeed until submission is attempted.

cardano-cli: DecoderFailure (LocalStateQuery HardForkBlock (': * ByronBlock (': * (ShelleyBlock (TPraos StandardCrypto) (ShelleyEra StandardCrypto)) (': * (ShelleyBlock (TPraos StandardCrypto) (AllegraEra StandardCrypto)) (': * (ShelleyBlock (TPraos StandardCrypto) (MaryEra StandardCrypto)) (': * (ShelleyBlock (TPraos StandardCrypto) (AlonzoEra StandardCrypto)) (': * (ShelleyBlock (Praos StandardCrypto) (BabbageEra StandardCrypto)) (': * (ShelleyBlock (Praos StandardCrypto) (ConwayEra StandardCrypto)) ('[] *)))))))) Query (BlockQuery (HardForkBlock (': * ByronBlock (': * (ShelleyBlock (TPraos StandardCrypto) (ShelleyEra StandardCrypto)) (': * (ShelleyBlock (TPraos StandardCrypto) (AllegraEra StandardCrypto)) (': * (ShelleyBlock (TPraos StandardCrypto) (MaryEra StandardCrypto)) (': * (ShelleyBlock (TPraos StandardCrypto) (AlonzoEra StandardCrypto)) (': * (ShelleyBlock (Praos StandardCrypto) (BabbageEra StandardCrypto)) (': * (ShelleyBlock (Praos StandardCrypto) (ConwayEra StandardCrypto)) ('[] *))))))))))) ServerAgency TokQuerying BlockQuery (QueryIfCurrent (QS (QS (QS (QS (QS (QS (QZ (GetDRepState (fromList []))))))))))) (DeserialiseFailure 37 "Size mismatch when decoding Record RecD.\nExpected 4, but found 3.")