chore(lint): update and fix prettier & eslint (#4452)

- chore(deps): update dependency prettier to v3
- chore(deps): update typescript-eslint monorepo to v6 (major)
- chore(deps): update dependency eslint-plugin-prettier to v5
- disable new `@typescript-eslint/class-methods-use-this` rule
- migrate some logical or (`||`) operators to nullish coalescing (`??`) operator

.eslintrc.cjs

@@ -35,6 +35,7 @@ module.exports = {
       },
     ],
     'import/no-default-export': 'error',
+    'import/no-duplicates': 'error',
     'import/no-extraneous-dependencies': ['error', {'devDependencies': false, 'optionalDependencies': false, 'peerDependencies': true}],
 
     // prettier rules
@@ -69,6 +70,7 @@ module.exports = {
     ],
     '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_*', ignoreRestSiblings: true, varsIgnorePattern: '^_' }],
     '@typescript-eslint/no-floating-promises': 'error',
+    '@typescript-eslint/class-methods-use-this': 'off',
 
     // disabled typescript-eslint rules we should enable in some way
 

e2e/tasks/bootstrap.js

@@ -39,7 +39,7 @@ from(dirs)
         }
       }
       return dir;
-    }, concurrency)
+    }, concurrency),
   )
   .subscribe({
     next: (dir) => {

e2e/tasks/run-e2e-tests.js

@@ -37,7 +37,7 @@ function runE2eTests() {
   const concurrency = Math.max(os.cpus().length / 2, 2);
   return test$.pipe(
     mergeAll(concurrency),
-    tap((testDir) => console.log(`\u2714 ${testDir} tested (${++testsRan}/${testDirs.length})`))
+    tap((testDir) => console.log(`\u2714 ${testDir} tested (${++testsRan}/${testDirs.length})`)),
   );
 }
 

e2e/test/disable-bail/verify/verify.js

@@ -37,7 +37,7 @@ describe('disableBail', () => {
  */
 async function arrangeActAssertBailWasDisabled(
   testRunner,
-  expectedKilledBy = ['add should result in 42 for 40 and 2', 'add should result in 42 for 41 and 1']
+  expectedKilledBy = ['add should result in 42 for 40 and 2', 'add should result in 42 for 41 and 1'],
 ) {
   const { exitCode } = execStryker(`stryker run --testRunner ${testRunner}`);
   expect(exitCode).eq(0);

e2e/test/mono-schema/verify/verify.js

@@ -12,7 +12,7 @@ import { beforeEach } from 'mocha';
  * @type {import('ajv').SchemaObject}
  */
 const monoSchema = JSON.parse(
-  fs.readFileSync(new URL('../../../node_modules/@stryker-mutator/core/schema/stryker-schema.json', import.meta.url), 'utf-8')
+  fs.readFileSync(new URL('../../../node_modules/@stryker-mutator/core/schema/stryker-schema.json', import.meta.url), 'utf-8'),
 );
 const valid = JSON.parse(fs.readFileSync(new URL('../test/valid.json', import.meta.url), 'utf-8'));
 const invalid = JSON.parse(fs.readFileSync(new URL('../test/invalid.json', import.meta.url), 'utf-8'));

e2e/test/options-validation/verify/verify.js

@@ -37,7 +37,7 @@ describe('Options validation', () => {
     });
     it('should report about unserializable options', () => {
       expect(result.stdout).includes(
-        ' Config option "myCustomReporter.filter" is not (fully) serializable. Primitive type "function" has no JSON representation. Any test runner or checker worker processes might not receive this value as intended.'
+        ' Config option "myCustomReporter.filter" is not (fully) serializable. Primitive type "function" has no JSON representation. Any test runner or checker worker processes might not receive this value as intended.',
       );
     });
   });

e2e/test/reporters-e2e/verify/verify.js

@@ -30,12 +30,12 @@ describe('Verify stryker has ran correctly', () => {
     const files = Object.fromEntries(
       Object.entries(result.files)
         .map(([fileName, fileResult]) => [fileName, { ...fileResult, mutants: fileResult.mutants.sort((a, b) => (a.id < b.id ? -1 : 1)) }])
-        .sort(([a], [b]) => (a < b ? -1 : 1))
+        .sort(([a], [b]) => (a < b ? -1 : 1)),
     );
     const testFiles = Object.fromEntries(
       Object.entries(result.testFiles)
         .map(([fileName, fileResult]) => [fileName, { ...fileResult, tests: fileResult.tests.sort((a, b) => (a.id < b.id ? -1 : 1)) }])
-        .sort(([a], [b]) => (a < b ? -1 : 1))
+        .sort(([a], [b]) => (a < b ? -1 : 1)),
     );
     expect(files).matchSnapshot();
     expect(testFiles).matchSnapshot();