add forge tests

contracts/.gitignore

@@ -13,4 +13,13 @@ deployments/localhost
 /coverage-data.json
 cache
 artifacts
-docs
+docs
+
+# foundry
+forge-cache/
+forge-artifacts/
+
+# Note: by default we ignore lib/forge-std as we do not use submodules
+# install it via `git clone --recursive https://github.com/foundry-rs/forge-std.git lib/forge-std`
+lib/forge-std
+

contracts/README.md

@@ -8,10 +8,28 @@ pnpm compile
 
 ### Test your contracts
 
+There is 2 flavors of test
+
+1. Using hardhat
+
 ```bash
 pnpm test
 ```
 
+2. Using foundry
+
+```bash
+forge test
+```
+
+This assumes you have `forge` installed and that you added forge-std in via the following command
+
+```bash
+git clone --recursive https://github.com/foundry-rs/forge-std.git lib/forge-std
+```
+
+You can also add it as a submodule if you prefers
+
 ### watch for changes and rebuild automatically
 
 ```bash

contracts/foundry.toml

@@ -0,0 +1,12 @@
+[profile.default]
+src = "src"
+out = "forge-artifacts"
+libs = ["node_modules", "lib"]
+remappings = [
+    "hardhat/=node_modules/hardhat/",
+    "solidity-proxy/=node_modules/solidity-proxy/"
+]
+test = 'test/foundry'
+cache_path  = 'forge-cache'
+
+# See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options

contracts/remappings.txt

@@ -0,0 +1,2 @@
+ds-test/=lib/forge-std/lib/ds-test/src/
+forge-std/=lib/forge-std/src/

contracts/test/foundry/GreetingsRegistry.t.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.13;
+
+import {Test, console2} from "forge-std/Test.sol";
+import {GreetingsRegistry} from "../../src/GreetingsRegistry.sol";
+
+contract GreetingsRegistryTest is Test {
+    GreetingsRegistry public registry;
+
+    function setUp() public {
+        registry = new GreetingsRegistry("");
+    }
+
+    function test_setMessage() public {
+        registry.setMessage("hello", 0);
+        assertEq(registry.lastGreetingOf(address(this)), "hello");
+    }
+}