Run eslint on the scripts directory

I noticed that the `scripts` directory, which begins to have a lot of
files as we automate more tasks (like #1524), wasn't linted.

That directory contains code in two languages BASH and JS (Node.js),
with a move to prefer JS files (as it's a JS/TS project).

So I chose to add an `.eslintrc.js` file (which is a deprecated format
but I couldn't make the new one work) and lint script on that
directory.

I subsequently fixed some linting errors.

For now, that script isn't run by our GitHub actions, I will see whether
we can do an intelligent kind of runner which detects if scripts have
been updated.

demo/.eslintrc.js

@@ -3,8 +3,6 @@ module.exports = {
   env: {
     es6: true,
     browser: true,
-    commonjs: true,
-    mocha: true,
   },
 
   globals: {

package.json

@@ -151,7 +151,7 @@
     "bundle:watch": "./scripts/run_bundler.mjs src/index.ts --production-mode -o dist/rx-player.js --watch",
     "certificate": "./scripts/generate_certificate",
     "check": "npm run check:types && npm run lint && npm run check:types:unit_tests",
-    "check:all": "npm run check:types && npm run lint && npm run lint:demo && npm run lint:tests && npm run test:unit && npm run test:integration && npm run test:memory && node -r esm ./scripts/check_nodejs_import_compatibility.js",
+    "check:all": "npm run check:types && npm run lint && npm run lint:demo && npm run lint:tests && npm run lint:scripts && npm run test:unit && npm run test:integration && npm run test:memory && node -r esm ./scripts/check_nodejs_import_compatibility.js",
     "check:demo": "npm run check:demo:types && npm run lint:demo",
     "check:demo:types": "tsc --noEmit --project demo/",
     "clean:build": "scripts/remove_dir.mjs dist",
@@ -169,6 +169,7 @@
     "fmt:rust:check": "cd ./src/parsers/manifest/dash/wasm-parser && cargo fmt --check",
     "lint": "eslint src -c .eslintrc.js",
     "lint:demo": "eslint -c demo/.eslintrc.js demo/scripts",
+    "lint:scripts": "eslint -c scripts/.eslintrc.js --ext .js --ext .mjs --ext .cjs scripts",
     "lint:tests": "eslint tests/**/*.js --ignore-pattern '/tests/performance/bundle*'",
     "list": "node scripts/list-npm-scripts.mjs",
     "prepublishOnly": "npm run build:all",

scripts/.eslintrc.js

@@ -0,0 +1,53 @@
+module.exports = {
+  root: true,
+  parserOptions: {
+    ecmaVersion: 2020,
+    sourceType: "module",
+  },
+  env: {
+    es6: true,
+    node: true,
+    commonjs: true,
+  },
+  extends: ["prettier"],
+  rules: {
+    "comma-dangle": [1, "only-multiline"],
+    "no-cond-assign": 0,
+    "no-constant-condition": 0,
+    "no-control-regex": 0,
+    "no-debugger": 2,
+    "no-dupe-args": 2,
+    "no-dupe-keys": 2,
+    "no-duplicate-case": 1,
+    "no-empty-character-class": 1,
+    "no-empty": 0,
+    "no-ex-assign": 1,
+    "no-extra-boolean-cast": 1,
+    "no-extra-parens": [1, "functions"],
+    "no-extra-semi": 2,
+    "no-func-assign": 2,
+    "no-inner-declarations": 0,
+    "no-invalid-regexp": 1,
+    "no-irregular-whitespace": 1,
+    "no-negated-in-lhs": 2,
+    "no-obj-calls": 2,
+    "no-regex-spaces": 1,
+    "no-sparse-arrays": 2,
+    "no-unreachable": 2,
+    "use-isnan": 2,
+    "valid-jsdoc": 0,
+    "valid-typeof": 2,
+    "no-unexpected-multiline": 0,
+    "no-trailing-spaces": 2,
+    "no-multiple-empty-lines": 1,
+    "accessor-pairs": [1, { setWithoutGet: true }],
+    "block-scoped-var": 1,
+    complexity: 0,
+    curly: [1, "all"],
+    "no-case-declarations": 0,
+    "no-var": 1,
+    "prefer-const": 1,
+    "linebreak-style": [1, "unix"],
+    semi: [1, "always"],
+  },
+};

scripts/run_bundler.mjs

@@ -62,16 +62,18 @@ if (import.meta.url === pathToFileURL(process.argv[1]).href) {
   }
 
   try {
-    await runBundler(normalizedPath, {
+    runBundler(normalizedPath, {
       watch: shouldWatch,
       minify: shouldMinify,
       production,
       silent,
       outfile,
+    }).catch((err) => {
+      console.error(`ERROR: ${err}\n`);
+      process.exit(1);
     });
   } catch (err) {
     console.error(`ERROR: ${err}\n`);
-    displayHelp();
     process.exit(1);
   }
 }