Scalus node emulator

[sae3023]

This PR introduces the Scalus node emulator as one of the Provider implementations, allowing to write the code against the in-memory Emulator as if it was a real node.

It also migrates some of the tests to the scalus emulator, making it drastically faster (180s vs ±3s)

Note on vendored scalus

This PR depends on Scalus features not yet published to npm (Emulator.withState, getDelegation, getDatum, hasTx). The vendor/scalus/ directory contains a local build of scalus 0.15.0 so reviewers can pnpm install && pnpm test without any local setup. The pnpm override in root package.json points to ./vendor/scalus. This will be removed once scalus publishes the new version.

[sae3023]

this whole file is a test util, and I don't insist on it existing in this form

[hadelive]

Thanks, agreed. A small helper avoids duplicating the NodeEmulator setup across these tests, but I am fine reshaping or moving it if we want a more general test utility.

[sae3023]

if there's a util that does this better -- i'd really prefer to use it, maybe you can point it out

[hadelive]

I checked and do not see an exported utility for this. The closest is the private buildCostModels helper in Evaluation.ts, so I think we should extract shared protocol and cost-model defaults into evolution core instead of duplicating them here.

[solidsnakedev]

.

Posted without authorization — removed by request.

[hadelive]

Thank you for adding the Scalus-backed node emulator provider and the related transaction builder coverage. I reviewed the current PR head (caa932274b403bc1b9fee948084991bc174357c9) and I believe this needs changes before it is ready to merge.

The new @evolution-sdk/scalus-emulator package does not currently build. Running pnpm --filter @evolution-sdk/scalus-emulator build fails in packages/scalus-emulator/src/index.ts because NodeEmulatorConfig exposes ReadonlyArray values, while Scalus.EmulatorInitialState expects mutable arrays for stakeRegistrations, poolRegistrations, drepRegistrations, and datums. Please either copy these values into mutable arrays before constructing the Scalus state, or align the public config types with the Scalus API.

The new node-emulator test suite is also not green. Running pnpm --filter @evolution-sdk/devnet test -- NodeEmulator fails in packages/evolution-devnet/test/TxBuilder.Pool.NodeEmulator.test.ts for the retirePool case. The emulator rejects the retirement transaction with Pool certificate validation failed ... not registered, even though the test submits a pool registration first. This should be fixed or the test should be adjusted so the suite reliably validates the intended behavior.

There are also a few packaging and runtime concerns to address before publishing this package:

• packages/scalus-emulator/package.json exports ./src/index.ts and does not define a publishConfig override to point consumers at dist, unlike the existing packages. This would publish runtime exports that resolve to TypeScript source.
• The same package declares "sideEffects": [], but packages/scalus-emulator/src/index.ts relies on import-time registration via registerNodeEmulatorProviderFactory. Bundlers may remove import "@evolution-sdk/scalus-emulator", which would leave the provider factory unregistered.
• packages/evolution/package.json adds an optional peer dependency back to @evolution-sdk/scalus-emulator, while the emulator package peer-depends on @evolution-sdk/evolution. This introduces a workspace dependency cycle warning during install, and core does not appear to need a peer dependency on the emulator package.

Finally, ScalusEmulatorProvider.evaluateTx appears to ignore caller-supplied cost models from protocolParameters and recreates the Scalus slot config with hard-coded zeroSlot = 0 and slotLength = 1000. That can make evaluation disagree with submission for custom protocol parameters or slot configurations.

Verification performed:

• pnpm --filter @evolution-sdk/evolution type-check passed.
• pnpm --filter @evolution-sdk/scalus-uplc type-check passed.
• pnpm --filter @evolution-sdk/devnet type-check passed.
• pnpm --filter @evolution-sdk/scalus-emulator build failed as described above.
• pnpm --filter @evolution-sdk/devnet test -- NodeEmulator failed as described above.