refactor(world): add IWorldEvents with HelloWorld (#2358)

.changeset/selfish-weeks-explode.md

@@ -0,0 +1,5 @@
+---
+"@latticexyz/world": patch
+---
+
+Created an `IWorldEvents` interface with `HelloStore`, so all World events are defined in a single interface.

docs/pages/world/reference/world-external.mdx

@@ -591,7 +591,7 @@ function callFrom(
 [Git Source](https://github.com/latticexyz/mud/blob/main/packages/world/src/IWorldKernel.sol)
 
 **Inherits:**
-[IWorldModuleInstallation](/world/reference/world-external#iworldmoduleinstallation), [IWorldCall](/world/reference/world-external#iworldcall), [IWorldErrors](/world/reference/world-external#iworlderrors)
+[IWorldModuleInstallation](/world/reference/world-external#iworldmoduleinstallation), [IWorldCall](/world/reference/world-external#iworldcall), [IWorldErrors](/world/reference/world-external#iworlderrors), [IWorldEvents](/src/IWorldEvents.sol/interface.IWorldEvents.md)
 
 The IWorldKernel interface includes all methods that are part of the World contract's
 internal bytecode. Consumers should use the `IBaseWorld` interface instead, which includes dynamically
@@ -643,22 +643,6 @@ function initialize(IModule initModule) external;
 | ------------ | --------- | ----------------------------------------------------- |
 | `initModule` | `IModule` | The InitModule to be installed during initialization. |
 
-### Events
-
-#### HelloWorld
-
-_Emitted upon successful World initialization._
-
-```solidity
-event HelloWorld(bytes32 indexed worldVersion);
-```
-
-**Parameters**
-
-| Name           | Type      | Description                                 |
-| -------------- | --------- | ------------------------------------------- |
-| `worldVersion` | `bytes32` | The version of the World being initialized. |
-
 ## IWorldModuleInstallation
 
 [Git Source](https://github.com/latticexyz/mud/blob/main/packages/world/src/IWorldKernel.sol)

packages/world/src/IWorldEvents.sol

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: MIT
+pragma solidity >=0.8.24;
+
+import { IWorldErrors } from "./IWorldErrors.sol";
+import { IModule } from "./IModule.sol";
+import { ResourceId } from "./WorldResourceId.sol";
+
+/**
+ * @title IWorldEvents
+ * @author MUD (https://mud.dev) by Lattice (https://lattice.xyz)
+ * @dev We bundle these events in an interface (instead of at the file-level or in their corresponding library) so they can be inherited by IWorldKernel.
+ * This ensures that all events are included in the IWorldKernel ABI for proper decoding in the frontend.
+ */
+interface IWorldEvents {
+  /**
+   * @dev Emitted upon successful World initialization.
+   * @param worldVersion The version of the World being initialized.
+   */
+  event HelloWorld(bytes32 indexed worldVersion);
+}

packages/world/src/IWorldKernel.sol

@@ -4,6 +4,7 @@ pragma solidity >=0.8.24;
 import { IWorldErrors } from "./IWorldErrors.sol";
 import { IModule } from "./IModule.sol";
 import { ResourceId } from "./WorldResourceId.sol";
+import { IWorldEvents } from "./IWorldEvents.sol";
 
 /**
  * @title World Module Installation Interface
@@ -59,13 +60,7 @@ interface IWorldCall {
  * internal bytecode. Consumers should use the `IBaseWorld` interface instead, which includes dynamically
  * registered functions selectors from the `InitModule`.
  */
-interface IWorldKernel is IWorldModuleInstallation, IWorldCall, IWorldErrors {
-  /**
-   * @dev Emitted upon successful World initialization.
-   * @param worldVersion The version of the World being initialized.
-   */
-  event HelloWorld(bytes32 indexed worldVersion);
-
+interface IWorldKernel is IWorldModuleInstallation, IWorldCall, IWorldErrors, IWorldEvents {
   /**
    * @notice Retrieve the version of the World.
    * @return The version identifier of the World.

packages/world/src/World.sol

@@ -23,6 +23,7 @@ import { InitModuleAddress } from "./codegen/tables/InitModuleAddress.sol";
 
 import { IModule, IModule } from "./IModule.sol";
 import { IWorldKernel } from "./IWorldKernel.sol";
+import { IWorldEvents } from "./IWorldEvents.sol";
 
 import { FunctionSelectors } from "./codegen/tables/FunctionSelectors.sol";
 import { Balances } from "./codegen/tables/Balances.sol";
@@ -47,7 +48,7 @@ contract World is StoreData, IWorldKernel {
   /// @dev Event emitted when the World contract is created.
   constructor() {
     creator = msg.sender;
-    emit HelloWorld(WORLD_VERSION);
+    emit IWorldEvents.HelloWorld(WORLD_VERSION);
   }
 
   /**

packages/world/test/Factories.t.sol

@@ -12,6 +12,7 @@ import { InitModule } from "../src/modules/init/InitModule.sol";
 import { Create2Factory } from "../src/Create2Factory.sol";
 import { WorldFactory } from "../src/WorldFactory.sol";
 import { IWorldFactory } from "../src/IWorldFactory.sol";
+import { IWorldEvents } from "../src/IWorldEvents.sol";
 import { InstalledModules } from "../src/codegen/tables/InstalledModules.sol";
 import { NamespaceOwner } from "../src/codegen/tables/NamespaceOwner.sol";
 import { ROOT_NAMESPACE_ID } from "../src/constants.sol";
@@ -20,7 +21,6 @@ import { createInitModule } from "./createInitModule.sol";
 contract FactoriesTest is Test, GasReporter {
   event ContractDeployed(address addr, uint256 salt);
   event WorldDeployed(address indexed newContract, uint256 salt);
-  event HelloWorld(bytes32 indexed version);
 
   function calculateAddress(
     address deployingAddress,
@@ -71,7 +71,7 @@ contract FactoriesTest is Test, GasReporter {
 
     // Check for HelloWorld event from World
     vm.expectEmit(true, true, true, true);
-    emit HelloWorld(WORLD_VERSION);
+    emit IWorldEvents.HelloWorld(WORLD_VERSION);
 
     // Check for WorldDeployed event from Factory
     vm.expectEmit(true, false, false, false);
@@ -104,7 +104,7 @@ contract FactoriesTest is Test, GasReporter {
 
     // Check for HelloWorld event from World
     vm.expectEmit(true, true, true, true);
-    emit HelloWorld(WORLD_VERSION);
+    emit IWorldEvents.HelloWorld(WORLD_VERSION);
 
     // Check for WorldDeployed event from Factory
     vm.expectEmit(true, false, false, false);

packages/world/test/World.t.sol

@@ -31,6 +31,7 @@ import { WorldContextProviderLib, IWorldContextConsumer } from "../src/WorldCont
 import { SystemHook } from "../src/SystemHook.sol";
 import { BEFORE_CALL_SYSTEM, AFTER_CALL_SYSTEM } from "../src/systemHookTypes.sol";
 import { Module, IModule } from "../src/Module.sol";
+import { IWorldEvents } from "../src/IWorldEvents.sol";
 
 import { NamespaceOwner } from "../src/codegen/tables/NamespaceOwner.sol";
 import { ResourceAccess } from "../src/codegen/tables/ResourceAccess.sol";
@@ -162,7 +163,6 @@ contract RevertSystemHook is SystemHook {
 contract WorldTest is Test, GasReporter {
   using WorldResourceIdInstance for ResourceId;
 
-  event HelloWorld(bytes32 indexed worldVersion);
   event HookCalled(bytes data);
   event SystemHookCalled(bytes data);
   event WorldTestSystemLog(string log);
@@ -200,7 +200,7 @@ contract WorldTest is Test, GasReporter {
     InitModule initModule = createInitModule();
 
     vm.expectEmit(true, true, true, true);
-    emit HelloWorld(WORLD_VERSION);
+    emit IWorldEvents.HelloWorld(WORLD_VERSION);
     IBaseWorld newWorld = IBaseWorld(address(new World()));
     StoreSwitch.setStoreAddress(address(newWorld));