test: simplify detection of ESLint major version (#1758)

Author: G-Rath

src/rules/__tests__/test-utils.ts

@@ -8,7 +8,8 @@ const eslintRequire = createRequire(require.resolve('eslint'));
 
 export const espreeParser = eslintRequire.resolve('espree');
 
-export const usingFlatConfig = semver.major(eslintVersion) >= 9;
+export const eslintMajorVersion = semver.major(eslintVersion);
+export const usingFlatConfig = eslintMajorVersion >= 9;
 
 export class FlatCompatRuleTester extends TSESLint.RuleTester {
   public constructor(testerConfig?: TSESLint.RuleTesterConfig) {

src/rules/utils/__tests__/parseJestFnCall.test.ts

@@ -1,8 +1,8 @@
-import type { JSONSchemaForNPMPackageJsonFiles } from '@schemastore/package';
 import type { TSESTree } from '@typescript-eslint/utils';
 import dedent from 'dedent';
 import {
   FlatCompatRuleTester as RuleTester,
+  eslintMajorVersion,
   espreeParser,
 } from '../../__tests__/test-utils';
 import {
@@ -14,24 +14,6 @@ import {
   parseJestFnCall,
 } from '../../utils';
 
-const findESLintVersion = (): number => {
-  const eslintPath = require.resolve('eslint/package.json');
-
-  const eslintPackageJson =
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    require(eslintPath) as JSONSchemaForNPMPackageJsonFiles;
-
-  if (!eslintPackageJson.version) {
-    throw new Error('eslint package.json does not have a version!');
-  }
-
-  const [majorVersion] = eslintPackageJson.version.split('.');
-
-  return parseInt(majorVersion, 10);
-};
-
-const eslintVersion = findESLintVersion();
-
 const ruleTester = new RuleTester({
   parser: espreeParser,
   parserOptions: {
@@ -463,7 +445,7 @@ ruleTester.run('esm', rule, {
   invalid: [],
 });
 
-if (eslintVersion >= 8) {
+if (eslintMajorVersion >= 8) {
   ruleTester.run('esm (dynamic)', rule, {
     valid: [
       {