test: Use the ES modules directly

This avoids the need for the generated CJS files and use of rollup in testing.

Thanks to https://remysharp.com/2019/08/16/build-free-code-and-testing-es-module-imports
and avajs/ava#2417 (comment) :-).

Author: matatk

.eslintrc.json

@@ -5,12 +5,14 @@
     "node": true
   },
   "extends": "eslint:recommended",
-  "overrides": [{
-    "files": ["test/rollup.config.js"],
-    "parserOptions": {
-      "sourceType": "module"
+  "overrides": [
+    {
+      "files": ["test/test*.js"],
+      "parserOptions": {
+        "sourceType": "module"
+      }
     }
-  }],
+  ],
   "parserOptions": {
     "ecmaVersion": 2018
   },

package-lock.json

@@ -13,8 +13,8 @@
     "start:edge": "npm run start:_core -- --source-dir build/edge --target chromium --chromium-binary '/Applications/Microsoft Edge.app/Contents/MacOS/Microsoft Edge'",
     "start:firefox": "npm run start:_core -- --source-dir build/firefox",
     "start:opera": "npm run start:_core -- --source-dir build/opera --target chromium --chromium-binary /Applications/Opera.app/Contents/MacOS/opera",
-    "pretest": "eslint . && rollup -c test/rollup.config.js",
-    "test": "npx nyc --exclude 'test/test*js' --reporter text --reporter html ava && npm run test:css",
+    "pretest": "eslint .",
+    "test": "npx nyc --reporter text --reporter html ava && npm run test:css",
     "test:css": "npx stylelint --config .stylelintrc.json src/**/*.css",
     "version": "standard-version --tag-prefix="
   },
@@ -23,12 +23,15 @@
       "pre-commit": "npm run build:all"
     }
   },
+  "esm": { "cjs": true },
   "ava": {
     "files": [
       "!test/generated-*.js",
       "!test/rollup.config.js"
-    ]
+    ],
+    "require": ["esm"]
   },
+  "nyc": { "require": ["esm"] },
   "devDependencies": {
     "addons-linter": "^2.1.0",
     "archiver-promise": "~1.0",
@@ -37,6 +40,7 @@
     "deepmerge": "~4.2",
     "dependency-tree": "^7.2.1",
     "eslint": "^7.5.0",
+    "esm": "^3.2.25",
     "fs-extra": "^9.0.1",
     "husky": "^4.2.5",
     "jsdom": "^16.3.0",

package.json

@@ -1,6 +1,5 @@
-'use strict'
-const test = require('ava')
-const ContrastChecker = require('./generated-contrast-checker.js')
+import test from 'ava'
+import ContrastChecker from '../src/code/contrastChecker'
 
 const contrastChecker = new ContrastChecker()
 

test/rollup.config.js

@@ -1,8 +1,7 @@
-'use strict'
-const test = require('ava')
-const jsdom = require('jsdom')
-const pssst = require('page-structural-semantics-scanner-tests')
-const LandmarksFinder = require('./generated-landmarks-finder')
+import test from 'ava'
+import jsdom from 'jsdom'
+import pssst from 'page-structural-semantics-scanner-tests'
+import LandmarksFinder from '../src/code/landmarksFinder'
 
 const { JSDOM } = jsdom
 const checks = pssst.getFullPageTestsInline()

test/testContrastChecker.js

@@ -1,7 +1,6 @@
 /* eslint-disable no-prototype-builtins */
-'use strict'
-const test = require('ava')
-const MigrationManager = require('./generated-migration-manager.js')
+import test from 'ava'
+import MigrationManager from '../src/code/migrationManager'
 
 // The purpose of the migration manager is to delete obsolete user settings, or
 // rename existing user settings to their current names. Landmarks ships with