fixes for createServer

[kanej]

This includes two small changes but touches the type of network.createServer.

1. It alters the network parameters type to allow chain types other than generic
2. It throws if createServer is used against a network config that is not edr-simulated (copying the pattern in npx hardhat node)

The changes are commit at a time.

createServer Type

The current type would show an error for the following code:

import { network } from "hardhat";

const server = await network.createServer(
  {
    network: "edrOp",
    chainType: "op", // <------ error: expected "generic"
  },
  "0.0.0.0",
  8545,
);

This PR accepts op without a type error. An alternative is to say that chainType makes no sense for the createServer method and Omit<> the property from the createServer interface.

[changeset-bot]

🦋 Changeset detected

Latest commit: 0a7deea

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
hardhat	Patch
@nomicfoundation/hardhat-errors	Patch

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[Copilot]

Pull request overview

Updates network.createServer to better support non-generic chain types while enforcing that servers can only be created from edr-simulated network configs (mirroring hardhat node behavior).

Changes:

• Generalize NetworkManager.createServer typing to accept NetworkConnectionParams<ChainTypeT> so chainType: "op" (and other chain types) type-checks.
• Add a runtime guard that throws a dedicated Hardhat error when createServer targets a non-edr-simulated network (e.g. http/localhost).
• Add tests + a new example script demonstrating spinning up a server and sending a tx.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
v-next/hardhat/test/internal/builtin-plugins/network-manager/network-manager.ts	Adds coverage for the new createServer restriction and validates server usage end-to-end.
v-next/hardhat/src/types/network.ts	Adjusts the public NetworkManager.createServer type signature to accept non-default chainTypes.
v-next/hardhat/src/internal/builtin-plugins/network-manager/network-manager.ts	Enforces createServer is only usable for edr-simulated networks via a new guard + dedicated error.
v-next/hardhat-errors/src/descriptors.ts	Introduces CREATE_SERVER_UNSUPPORTED_NETWORK_TYPE error descriptor for the new runtime validation.
v-next/example-project/scripts/create-server.ts	Adds an example script demonstrating network.createServer with chainType: "op".

---

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[kanej]

This is the key type change. It is backwards compatible.

The alternative is to remove chainType as it does not make sense for createServer (no connection instance is returned).

[Copilot]

Pull request overview

This PR updates network.createServer to (1) accept non-"generic" chainTypes in its parameter typing, and (2) fail fast at runtime when called against an http network configuration (matching the behavior pattern used by hardhat node).

Changes:

• Updated network.createServer TypeScript signature to support typed non-generic chainType values.
• Added a runtime guard that throws a dedicated Hardhat error when createServer targets a non-edr-simulated network config, plus added corresponding tests.
• Added a new error descriptor and an example script demonstrating createServer.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
v-next/hardhat/test/internal/builtin-plugins/network-manager/network-manager.ts	Adds coverage for rejecting createServer on http networks and validates server connectivity.
v-next/hardhat/src/types/network.ts	Makes createServer generic over ChainTypeT to allow non-"generic" chain types in params.
v-next/hardhat/src/internal/builtin-plugins/network-manager/network-manager.ts	Adds a guard that throws when createServer is invoked for non-edr-simulated network configs.
v-next/hardhat-errors/src/descriptors.ts	Introduces CREATE_SERVER_UNSUPPORTED_NETWORK_TYPE error descriptor.
v-next/example-project/scripts/create-server.ts	Adds an example using network.createServer and interacting with the resulting JSON-RPC server.
.changeset/petite-teams-slide.md	Changeset for the new runtime guard / error.
.changeset/cyan-dogs-ask.md	Changeset for the createServer typing update.

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[Copilot]

Pull request overview

Updates network.createServer to better support different chain types at the type level and to fail fast when invoked against unsupported (HTTP) network configurations.

Changes:

• Generalized NetworkManager.createServer typing to accept non-generic chainType values via generics.
• Added a runtime guard that throws a dedicated Hardhat error when createServer targets a non-edr-simulated network.
• Expanded createServer tests and added new error descriptor + changesets.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
v-next/hardhat/test/internal/builtin-plugins/network-manager/network-manager.ts	Adds regression tests for createServer rejecting HTTP networks and validates the server can be used via an HTTP client.
v-next/hardhat/src/types/network.ts	Updates the public NetworkManager.createServer signature to be generic over ChainType.
v-next/hardhat/src/internal/builtin-plugins/network-manager/network-manager.ts	Implements the runtime guard and updates createServer signature accordingly.
v-next/hardhat-errors/src/descriptors.ts	Introduces CREATE_SERVER_UNSUPPORTED_NETWORK_TYPE error descriptor.
.changeset/petite-teams-slide.md	Changeset for the new createServer guard behavior.
.changeset/cyan-dogs-ask.md	Changeset for the createServer type signature update.

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