imp(contracts): Add contracts directory and compilation script

CHANGELOG.md

@@ -8,6 +8,7 @@ This changelog was created using the `clu` binary
 
 ### Improvements
 
+- (contracts) [#24](https://github.com/evmos/os/pull/24) Add contracts directory and compilation script.
 - (cli) [#23](https://github.com/evmos/os/pull/23) Add client, cmd and version packages.
 - (server) [#22](https://github.com/evmos/os/pull/22) Add server implementation.
 - (rpc) [#21](https://github.com/evmos/os/pull/21) Add RPC and indexer types.

contracts/.gitignore

@@ -0,0 +1,8 @@
+# Compiled contracts
+artifacts/
+
+# Cached files
+cache/
+
+# Node modules
+node_modules/

contracts/erc20.go

@@ -0,0 +1,30 @@
+// Copyright Tharsis Labs Ltd.(Evmos)
+// SPDX-License-Identifier:ENCL-1.0(https://github.com/evmos/evmos/blob/main/LICENSE)
+
+package contracts
+
+import (
+	_ "embed"
+
+	evmtypes "github.com/evmos/evmos/v19/x/evm/types"
+	contractutils "github.com/evmos/os/contracts/utils"
+)
+
+var (
+	// ERC20MinterBurnerDecimalsJSON are the compiled bytes of the ERC20MinterBurnerDecimalsContract
+	//
+	//go:embed solidity/ERC20MinterBurnerDecimals.json
+	ERC20MinterBurnerDecimalsJSON []byte
+
+	// ERC20MinterBurnerDecimalsContract is the compiled erc20 contract
+	ERC20MinterBurnerDecimalsContract evmtypes.CompiledContract
+)
+
+func init() {
+	var err error
+	if ERC20MinterBurnerDecimalsContract, err = contractutils.ConvertHardhatBytesToCompiledContract(
+		ERC20MinterBurnerDecimalsJSON,
+	); err != nil {
+		panic(err)
+	}
+}

contracts/hardhat.config.js

@@ -0,0 +1,7 @@
+/** @type import('hardhat/config').HardhatUserConfig */
+module.exports = {
+  solidity: '0.8.19',
+  paths: {
+    sources: './solidity'
+  }
+}