Eslint rule updates (#673)

* Install unicorn

* Add rules

* Fix issues

* Install sonarjs

* Set up rules

* Fix issues

* Install eslint-plugin-import and fix import extensions

* Simplify permitted error names

12 files changed, 30 insertions, 25 deletions

diff --git a/test/css-json.test.js b/test/css-json.test.js
index b64419c3..87d24d6c 100644
--- a/test/css-json.test.js
+++ b/test/css-json.test.js
@@ -18,7 +18,7 @@
 
 import fs from 'fs';
 import {describe, expect, test} from 'vitest';
-import {formatRulesJson, generateRules, getTargets} from '../dev/generate-css-json';
+import {formatRulesJson, generateRules, getTargets} from '../dev/generate-css-json.js';
 
 /** */
 function main() {
diff --git a/test/data/html/js/html-test-utilities.js b/test/data/html/js/html-test-utilities.js
index b72b7fca..c3382456 100644
--- a/test/data/html/js/html-test-utilities.js
+++ b/test/data/html/js/html-test-utilities.js
@@ -16,6 +16,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+/**
+ * This is a static class because this file is not imported as a module.
+ */
+// eslint-disable-next-line unicorn/no-static-only-class
 class HtmlTestUtilities {
     /**
      * @param {Element} element
diff --git a/test/dictionary-data-validate.test.js b/test/dictionary-data-validate.test.js
index 4c96cdb0..b09e4ae0 100644
--- a/test/dictionary-data-validate.test.js
+++ b/test/dictionary-data-validate.test.js
@@ -48,11 +48,11 @@ describe('Dictionary validation', () => {
     describe.each(testCases)('Test dictionary $name', ({name, valid}) => {
         it(`should be ${valid ? 'valid' : 'invalid'}`, async ({expect}) => {
             const archive = createTestDictionaryArchive(name);
-            if (valid) {
-                await expect(dictionaryValidate.validateDictionary(null, archive, schemas)).resolves.not.toThrow();
-            } else {
-                await expect(dictionaryValidate.validateDictionary(null, archive, schemas)).rejects.toThrow();
-            }
+            await (
+                valid ?
+                expect(dictionaryValidate.validateDictionary(null, archive, schemas)).resolves.not.toThrow() :
+                expect(dictionaryValidate.validateDictionary(null, archive, schemas)).rejects.toThrow()
+            );
         });
     });
 });
diff --git a/test/document-util.test.js b/test/document-util.test.js
index 18a5d42c..c2b2edca 100644
--- a/test/document-util.test.js
+++ b/test/document-util.test.js
@@ -159,12 +159,13 @@ describe('Document utility tests', () => {
                         expect(!!imposter).toStrictEqual(!!hasImposter);
 
                         const range = document.createRange();
-                        range.setStart(/** @type {Node} */ (imposter ? imposter : startNode), startOffset);
-                        range.setEnd(/** @type {Node} */ (imposter ? imposter : startNode), endOffset);
+                        range.setStart(/** @type {Node} */ (imposter ?? startNode), startOffset);
+                        range.setEnd(/** @type {Node} */ (imposter ?? startNode), endOffset);
 
                         // Override getClientRects to return a rect guaranteed to contain (x, y)
                         range.getClientRects = () => {
                             /** @type {import('test/document-types').PseudoDOMRectList} */
+                            // eslint-disable-next-line sonarjs/prefer-immediate-return
                             const domRectList = Object.assign(
                                 [new DOMRect(x - 1, y - 1, 2, 2)],
                                 {
diff --git a/test/dom-text-scanner.test.js b/test/dom-text-scanner.test.js
index e86d2980..1ec7cab7 100644
--- a/test/dom-text-scanner.test.js
+++ b/test/dom-text-scanner.test.js
@@ -34,7 +34,7 @@ function querySelectorTextNode(element, selector) {
     let textIndex = -1;
     const match = /::text$|::nth-text\((\d+)\)$/.exec(selector);
     if (match !== null) {
-        textIndex = (match[1] ? parseInt(match[1], 10) - 1 : 0);
+        textIndex = (match[1] ? Number.parseInt(match[1], 10) - 1 : 0);
         selector = selector.substring(0, selector.length - match[0].length);
     }
     const result = element.querySelector(selector);
@@ -67,13 +67,11 @@ function getComputedFontSizeInPixels(window, getComputedStyle, element) {
         if (element.nodeType === window.Node.ELEMENT_NODE) {
             const fontSize = getComputedStyle(/** @type {Element} */ (element)).fontSize;
             if (fontSize.endsWith('px')) {
-                const value = parseFloat(fontSize.substring(0, fontSize.length - 2));
-                return value;
+                return Number.parseFloat(fontSize.substring(0, fontSize.length - 2));
             }
         }
     }
-    const defaultFontSize = 14;
-    return defaultFontSize;
+    return 14; // Default font size
 }
 
 /**
@@ -92,7 +90,7 @@ function createAbsoluteGetComputedStyle(window) {
                 if (typeof result === 'string') {
                     result = result.replace(/([-+]?\d(?:\.\d)?(?:[eE][-+]?\d+)?)em/g, (g0, g1) => {
                         const fontSize = getComputedFontSizeInPixels(window, getComputedStyleOld, element);
-                        return `${parseFloat(g1) * fontSize}px`;
+                        return `${Number.parseFloat(g1) * fontSize}px`;
                     });
                 }
                 return result;
diff --git a/test/fixtures/anki-template-renderer-test.js b/test/fixtures/anki-template-renderer-test.js
index de447126..635e0b7d 100644
--- a/test/fixtures/anki-template-renderer-test.js
+++ b/test/fixtures/anki-template-renderer-test.js
@@ -30,6 +30,7 @@ export async function createAnkiTemplateRendererTest() {
     const ankiTemplateRenderer = new AnkiTemplateRenderer();
     await ankiTemplateRenderer.prepare();
     /** @type {import('vitest').TestAPI<{window: import('jsdom').DOMWindow, ankiTemplateRenderer: AnkiTemplateRenderer}>} */
+    // eslint-disable-next-line sonarjs/prefer-immediate-return
     const result = test.extend({
         window: async ({window}, use) => { await use(window); },
         ankiTemplateRenderer: async ({window}, use) => {
diff --git a/test/fixtures/translator-test.js b/test/fixtures/translator-test.js
index a4c65b88..f39d832b 100644
--- a/test/fixtures/translator-test.js
+++ b/test/fixtures/translator-test.js
@@ -81,6 +81,7 @@ export async function createTranslatorTest(htmlFilePath, dictionaryDirectory, di
     const test = createDomTest(htmlFilePath);
     const translator = await createTranslatorContext(dictionaryDirectory, dictionaryName);
     /** @type {import('vitest').TestAPI<{window: import('jsdom').DOMWindow, translator: Translator}>} */
+    // eslint-disable-next-line sonarjs/prefer-immediate-return
     const result = test.extend({
         window: async ({window}, use) => { await use(window); },
         // eslint-disable-next-line no-empty-pattern
diff --git a/test/json.test.js b/test/json.test.js
index 0689913a..aa12dc09 100644
--- a/test/json.test.js
+++ b/test/json.test.js
@@ -110,11 +110,11 @@ describe.concurrent('JSON validation', () => {
 
     const existingJsonFiles = getAllFiles(rootDir, (path, isDirectory) => {
         const fileNameNormalized = normalizePathDirectorySeparators(path);
-        if (isDirectory) {
-            return !ignoreDirectories.has(fileNameNormalized);
-        } else {
-            return /\.json$/i.test(fileNameNormalized);
-        }
+        return (
+            isDirectory ?
+            !ignoreDirectories.has(fileNameNormalized) :
+            /\.json$/i.test(fileNameNormalized)
+        );
     });
     /** @type {Set<string>} */
     const existingJsonFileSet = new Set();
diff --git a/test/playwright/global.setup.js b/test/playwright/global.setup.js
index 8c2f8b50..63452397 100644
--- a/test/playwright/global.setup.js
+++ b/test/playwright/global.setup.js
@@ -18,8 +18,8 @@
 import {test as setup} from '@playwright/test';
 import fs from 'fs';
 import path from 'path';
-import {ManifestUtil} from '../../dev/manifest-util';
-import {root} from './playwright-util';
+import {ManifestUtil} from '../../dev/manifest-util.js';
+import {root} from './playwright-util.js';
 
 const manifestPath = path.join(root, 'ext/manifest.json');
 const copyManifestPath = path.join(root, 'ext/manifest-old.json');
diff --git a/test/playwright/global.teardown.js b/test/playwright/global.teardown.js
index f3d8897f..e747e5fd 100644
--- a/test/playwright/global.teardown.js
+++ b/test/playwright/global.teardown.js
@@ -18,7 +18,7 @@
 import {test as teardown} from '@playwright/test';
 import fs from 'fs';
 import path from 'path';
-import {root} from './playwright-util';
+import {root} from './playwright-util.js';
 
 const manifestPath = path.join(root, 'ext/manifest.json');
 const copyManifestPath = path.join(root, 'ext/manifest-old.json');
diff --git a/test/playwright/integration.spec.js b/test/playwright/integration.spec.js
index bdcfddf0..170714a1 100644
--- a/test/playwright/integration.spec.js
+++ b/test/playwright/integration.spec.js
@@ -16,7 +16,7 @@
  */
 
 import path from 'path';
-import {createDictionaryArchive} from '../../dev/util';
+import {createDictionaryArchive} from '../../dev/util.js';
 import {
     expect,
     expectedAddNoteBody,
@@ -26,7 +26,7 @@ import {
     root,
     test,
     writeToClipboardFromPage
-} from './playwright-util';
+} from './playwright-util.js';
 
 test.beforeEach(async ({context}) => {
     // Wait for the on-install welcome.html tab to load, which becomes the foreground tab
diff --git a/test/playwright/visual.spec.js b/test/playwright/visual.spec.js
index cc2a50d0..fc8bb8df 100644
--- a/test/playwright/visual.spec.js
+++ b/test/playwright/visual.spec.js
@@ -17,7 +17,7 @@
 
 import path from 'path';
 import {pathToFileURL} from 'url';
-import {expect, root, test} from './playwright-util';
+import {expect, root, test} from './playwright-util.js';
 
 test.beforeEach(async ({context}) => {
     // Wait for the on-install welcome.html tab to load, which becomes the foreground tab