Get a basic foundry test running (compound-finance#606)

* Get a basic foundry test running

* Don't copy lib

* Attempt forge test workflow

* Document usage in the README

.github/workflows/run-forge-tests.yaml

@@ -0,0 +1,33 @@
+name: Run Forge Tests
+on:
+  workflow_dispatch:
+  pull_request:
+jobs:
+  forge-tests:
+    name: Forge tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          submodules: recursive
+
+      - name: Install Foundry
+        uses: onbjerg/foundry-toolchain@v1
+        with:
+          version: nightly
+
+      - name: Install dependencies
+        run: forge install
+
+      - name: Run tests
+        run: forge test -vvv
+        env:
+          ETHERSCAN_KEY: ${{ secrets.ETHERSCAN_KEY }}
+          SNOWTRACE_KEY: ${{ secrets.SNOWTRACE_KEY }}
+          INFURA_KEY: ${{ secrets.INFURA_KEY }}
+          POLYGONSCAN_KEY: ${{ secrets.POLYGONSCAN_KEY }}
+
+      - name: Build Comet with older solc versions
+        run: |
+          forge build --contracts contracts/Comet.sol --use solc:0.8.15

.gitignore

@@ -13,6 +13,8 @@ dist/
 deployments/*/.contracts
 deployments/*/*/verify
 deployments/*/*/aliases.json
+forge/cache
+forge/out
 
 .env
 coverage/

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "forge/lib/forge-std"]
+	path = forge/lib/forge-std
+	url = https://github.com/foundry-rs/forge-std

README.md

@@ -141,6 +141,17 @@ Set up the following env variables:
 - `COINMARKETCAP_API_KEY=your_coinmarket_api_key`
   optional, only if you want to see cost in USD
 
+### Run forge tests
+
+Experimental support for `foundry` has been added, so assuming `forge` is installed:
+
+```
+forge test
+```
+
+See the [GitHub workflow](.github/workflows/run-forge-tests.yaml) for an example.
+
+
 ### Deploy contracts
 
 Deploys contracts to a specified chain using a deployment script.

forge/test/Comet.t.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.13;
+
+import "forge-std/Test.sol";
+import "../../contracts/Comet.sol";
+import "../../contracts/CometConfiguration.sol";
+
+contract CometTest is Test {
+    Comet public comet;
+
+    function setUp() public {
+        // XXX
+    }
+
+    function testFailXXX() public {
+        CometConfiguration.AssetConfig[] memory assets = new CometConfiguration.AssetConfig[](0);
+        CometConfiguration.Configuration memory config =
+            CometConfiguration.Configuration(address(0),
+                          address(0),
+                          address(0),
+                          address(0),
+                          address(0),
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          0,
+                          assets);
+        comet = new Comet(config);
+    }
+}

foundry.toml

@@ -0,0 +1,6 @@
+[profile.default]
+src = 'contracts'
+out = 'forge/out'
+libs = ['node_modules', 'forge/lib']
+test = 'forge/test'
+cache_path  = 'forge/cache'