feat: add metadata event emitter contract (#1138)

Author: amateima

contracts/AcrossEventEmitter.sol

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.0;
+
+/**
+ * @title AcrossEventEmitter
+ * @notice A simple contract that emits events with bytes encoded metadata
+ */
+contract AcrossEventEmitter {
+    /**
+     * @notice Emitted when metadata is stored
+     * @param data The metadata bytes emitted
+     */
+    event MetadataEmitted(bytes data);
+
+    /**
+     * @notice Emits metadata as an event
+     * @param data The bytes data to emit
+     */
+    function emitData(bytes calldata data) external {
+        require(data.length > 0, "Data cannot be empty");
+        emit MetadataEmitted(data);
+    }
+}

deploy/114_deploy_across_event_emitter.ts

@@ -0,0 +1,15 @@
+import { DeployFunction } from "hardhat-deploy/types";
+import { HardhatRuntimeEnvironment } from "hardhat/types";
+
+const func: DeployFunction = async function (hre: HardhatRuntimeEnvironment) {
+  const { deployer } = await hre.getNamedAccounts();
+  const instance = await hre.deployments.deploy("AcrossEventEmitter", {
+    from: deployer,
+    log: true,
+    skipIfAlreadyDeployed: true,
+  });
+  await hre.run("verify:verify", { address: instance.address });
+};
+
+module.exports = func;
+func.tags = ["AcrossEventEmitter"];