chore(eslint): Add ESLint TypeScript linting

.eslintignore

@@ -6,3 +6,9 @@ node6/*
 node6-test/*
 experimental/
 lib/
+src/externs.d.ts
+src/protocol.d.ts
+/index.d.ts
+# We ignore this file because it uses ES imports which we don't yet use
+# in the Puppeteer src, so it trips up the ESLint-TypeScript parser.
+utils/doclint/generate_types/test/test.ts

.eslintrc.js

@@ -1,34 +1,18 @@
 module.exports = {
     "root": true,
-
     "env": {
         "node": true,
         "es6": true
     },
 
-    "parserOptions": {
-        "ecmaVersion": 9
-    },
+    "parser": "@typescript-eslint/parser",
 
     "plugins": [
-        "mocha"
+        "mocha",
+        "@typescript-eslint"
     ],
 
-    /**
-     * ESLint rules
-     *
-     * All available rules: http://eslint.org/docs/rules/
-     *
-     * Rules take the following form:
-     *   "rule-name", [severity, { opts }]
-     * Severity: 2 == error, 1 == warning, 0 == off.
-     */
     "rules": {
-        /**
-         * Enforced rules
-         */
-
-
         // syntax preferences
         "quotes": [2, "single", {
             "avoidEscape": true,
@@ -115,5 +99,15 @@ module.exports = {
 
         // ensure we don't have any it.only or describe.only in prod
         "mocha/no-exclusive-tests": "error"
-    }
+    },
+    "overrides": [
+        {
+            // apply TypeScript linting to the TS files in src/
+            "files": ["src/*.ts"],
+            "extends": [
+                'plugin:@typescript-eslint/eslint-recommended',
+                'plugin:@typescript-eslint/recommended',
+            ]
+        }
+    ]
 };

package.json

@@ -21,7 +21,7 @@
     "prepublishOnly": "npm run tsc",
     "dev-install": "npm run tsc && node install.js",
     "install": "node install.js",
-    "lint": "([ \"$CI\" = true ] && eslint --quiet -f codeframe . || eslint .) && npm run tsc && npm run doc",
+    "lint": "([ \"$CI\" = true ] && eslint --ext js --ext ts --quiet -f codeframe . || eslint --ext js --ext ts .) && npm run tsc && npm run doc",
     "doc": "node utils/doclint/cli.js",
     "tsc": "tsc --version && tsc -p . && cp src/protocol.d.ts lib/ && cp src/externs.d.ts lib/",
     "apply-next-version": "node utils/apply_next_version.js",
@@ -53,6 +53,8 @@
     "@types/rimraf": "^2.0.2",
     "@types/tar-fs": "^1.16.2",
     "@types/ws": "^6.0.1",
+    "@typescript-eslint/eslint-plugin": "^2.28.0",
+    "@typescript-eslint/parser": "^2.28.0",
     "commonmark": "^0.28.1",
     "cross-env": "^5.0.5",
     "eslint": "^6.8.0",

src/DeviceDescriptors.ts

@@ -25,7 +25,7 @@ interface Device {
     hasTouch: boolean;
     isLandscape: boolean;
   };
-};
+}
 
 const devices: Device[] = [
   {
@@ -888,8 +888,8 @@ type DevicesMap = {
 
 const devicesMap: DevicesMap = {};
 
-for (const device of devices) {
+for (const device of devices)
   devicesMap[device.name] = device;
-}
+
 
 export = devicesMap;