Add lint/format CI checks (#43)

* Add lint/format CI checks

* Add eslint config file and packages

* Add prettier dependency and config

* Fix formatting in config files

* test changed file check

* fix lint and format error in changed source file

.eslintrc.js

@@ -0,0 +1,42 @@
+/* eslint-env node */
+module.exports = {
+  parser: "@typescript-eslint/parser",
+  plugins: ["@typescript-eslint", "simple-import-sort"],
+
+  parserOptions: {
+    project: true,
+  },
+
+  extends: [
+    "plugin:@typescript-eslint/strict-type-checked",
+    "plugin:@typescript-eslint/stylistic-type-checked",
+    "prettier",
+  ],
+
+  rules: {
+    "@typescript-eslint/consistent-type-imports": "error",
+    "simple-import-sort/imports": "error",
+    camelcase: ["error", { properties: "always" }],
+    eqeqeq: ["error", "always"],
+    "prefer-const": "error",
+    "@typescript-eslint/no-throw-literal": "error",
+    "@typescript-eslint/switch-exhaustiveness-check": "error",
+    // Specifically allow "_" as a placeholder argument name
+    "@typescript-eslint/no-unused-vars": ["error", { argsIgnorePattern: "^_$" }],
+  },
+
+  overrides: [
+    {
+      files: ["./*.js", "./*.mjs"], // config files
+      env: { node: true },
+      extends: ["plugin:@typescript-eslint/disable-type-checked"],
+      rules: {
+        "@typescript-eslint/no-var-requires": "off",
+      },
+    },
+    {
+      files: ["**/*.test.ts"],
+      plugins: ["jest"],
+    },
+  ],
+};

.github/workflows/lint.yaml

@@ -0,0 +1,53 @@
+name: lint
+
+on:
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  eslint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v3
+        with:
+          cache: "npm"
+
+      - run: npm ci
+
+      - name: Run eslint on changed files
+        uses: tj-actions/eslint-changed-files@v20
+        with:
+          reporter: github-check
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+  prettier:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v3
+        with:
+          cache: "npm"
+
+      - run: npm ci
+
+      - name: Get changed files
+        id: changed-files
+        uses: tj-actions/changed-files@v38
+
+      - run: npx prettier --check ${{ steps.changed-files.outputs.all_changed_files }}
+
+  actionlint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Check workflow files
+        uses: docker://rhysd/actionlint:latest
+        with:
+          args: -color

.github/workflows/test.yaml

@@ -25,6 +25,7 @@ jobs:
       - name: Run tests
         run: |
           tests=$(find ./codegen/src/ -name '*.test.pkl')
+          # shellcheck disable=SC2086
           pkl test $tests
 
   pkl-snippet:

.prettierrc

@@ -0,0 +1,7 @@
+{
+  "semi": true,
+  "tabWidth": 2,
+  "trailingComma": "all",
+  "useTabs": false,
+  "printWidth": 100
+}