Add linting support for Solidity and TypeScript files with Prettier and ESLint

.eslintrc

@@ -0,0 +1,21 @@
+{
+    "extends": ["eslint:recommended", "plugin:prettier/recommended"],
+    "plugins": ["prettier"],
+    "rules": {
+      "prettier/prettier": "error"
+    },
+    "overrides": [
+      {
+        "files": ["**/*.sol"],
+        "parser": "solidity-eslint-parser",
+        "plugins": ["solidity", "prettier"],
+        "rules": {
+          "prettier/prettier": ["error", { "parser": "solidity" }],
+          "no-unused-vars": "off",
+          "no-undef": "off",
+          "no-empty": "off"
+        }
+      }
+    ]
+  }
+

.github/workflows/.lint.yml

@@ -0,0 +1,19 @@
+name: Lint
+
+on:
+  push:
+    branches:
+      - v2
+  pull_request:
+    branches:
+      - v2
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies
+        run: npm install
+      - name: Prettier check
+        run: npm run prettier:solidity && npm run prettier:ts

.prettierrc

@@ -0,0 +1,25 @@
+{
+  "semi": false,
+  "singleQuote": true,
+  "printWidth": 120,
+  "tabWidth": 2,
+  "overrides": [
+    {
+        "files": "*.sol",
+        "options": {
+          "printWidth": 80,
+          "tabWidth": 4,
+          "useTabs": false,
+          "singleQuote": false,
+          "bracketSpacing": false,
+        }
+      },
+    {
+      "files": "*.json",
+      "options": {
+        "printWidth": 80,
+        "tabWidth": 2
+      }
+    }
+  ]
+}

.solhint.json

@@ -1,7 +1,9 @@
 {
   "extends": "solhint:recommended",
   "rules": {
+    "prettier/prettier": "error",
     "compiler-version": ["error", "^0.8.0"],
     "func-visibility": ["warn", { "ignoreConstructors": true }]
-  }
+  },
+  "plugins": ["prettier"]
 }