chore: add linting

Author: SimenB

.eslintrc

@@ -0,0 +1,18 @@
+{
+  "parser": "@typescript-eslint/parser",
+  "extends": [
+    "eslint:recommended",
+    "plugin:prettier/recommended"
+  ],
+  "env": {
+    "node": true
+  },
+  "overrides": [
+    {
+      "files": "**/*.ts",
+      "extends": [
+        "plugin:@typescript-eslint/eslint-recommended"
+      ]
+    }
+  ]
+}

.github/workflows/nodejs.yml

@@ -0,0 +1,25 @@
+name: Unit tests
+
+on:
+  push:
+    branches:
+      - main
+      - next
+  pull_request:
+    branches:
+      - main
+      - next
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: 14.x
+          cache: yarn
+      - name: install
+        run: yarn
+      - name: run ESLint
+        run: yarn lint

.gitignore

@@ -1,4 +1,5 @@
 node_modules/*
 .idea/*
 .vscode/*
+*.log
 

package.json

@@ -9,9 +9,25 @@
     "Karan Sanjeev Nair <[email protected]> (https://alphaman.me)",
     "Saurabh Agarwala <[email protected]>"
   ],
+  "scripts": {
+    "lint": "eslint ."
+  },
   "dependencies": {
     "create-jest-runner": "^0.6.0",
     "jest-docblock": "^26.0.0",
     "mlh-tsd": "^0.14.1"
+  },
+  "devDependencies": {
+    "@typescript-eslint/eslint-plugin": "^5.0.0",
+    "@typescript-eslint/parser": "^5.0.0",
+    "eslint": "^7.32.0",
+    "eslint-config-prettier": "^8.3.0",
+    "eslint-plugin-prettier": "^3.4.1",
+    "prettier": "^2.4.1",
+    "typescript": "^4.4.4"
+  },
+  "prettier": {
+    "arrowParens": "avoid",
+    "singleQuote": true
   }
 }

src/fail.js

@@ -1,6 +1,13 @@
 const { toTestResult } = require('./toTestResult');
 
-module.exports.fail = ({ start, end, test, errorMessage, numFailed, numPassed }) => {
+module.exports.fail = ({
+  start,
+  end,
+  test,
+  errorMessage,
+  numFailed,
+  numPassed,
+}) => {
   const stats = {
     failures: numFailed,
     passes: numPassed,
@@ -14,7 +21,7 @@ module.exports.fail = ({ start, end, test, errorMessage, numFailed, numPassed })
     stats,
     title: 'Type Checks',
     errorMessage: errorMessage.join('\n'),
-    tests: [{duration: end - start, ...test}],
+    tests: [{ duration: end - start, ...test }],
     jestTestPath: test.path,
   });
 };

src/run.js

@@ -15,11 +15,10 @@ const findTypingsFile = testPath => {
   const parsedDocblocks = parse(fileContents);
   const typingsFile = parsedDocblocks.type || '';
 
-  if (typingsFile === 'undefined')
-    return '';
+  if (typingsFile === 'undefined') return '';
 
   return String(typingsFile);
-}
+};
 
 module.exports = async ({ testPath }) => {
   // Convert absolute path to relative path
@@ -28,7 +27,10 @@ module.exports = async ({ testPath }) => {
   const typingsFileRelativePath = findTypingsFile(testPath);
 
   // Remove filename from the path and join it with typingsFile relative path
-  const typingsFile = join(testFile.substring(0, testFile.lastIndexOf('/')), typingsFileRelativePath);
+  const typingsFile = join(
+    testFile.substring(0, testFile.lastIndexOf('/')),
+    typingsFileRelativePath
+  );
 
   const extendedDiagnostics = await tsd.default({
     cwd: process.cwd(),
@@ -46,14 +48,16 @@ module.exports = async ({ testPath }) => {
     let errorMessage = [];
 
     failedTests.forEach(test => {
-      errorMessage.push(`${testFile}:${test.line}:${test.column} - ${test.severity} - ${test.message}`);
+      errorMessage.push(
+        `${testFile}:${test.line}:${test.column} - ${test.severity} - ${test.message}`
+      );
     });
 
     return fail({
       start,
       end: +new Date(),
       test: {
-        path: testPath
+        path: testPath,
       },
       numFailed,
       numPassed,