chore: use eslint rule eqeqeq (#4234)

.eslintrc.js

@@ -14,6 +14,7 @@ module.exports = defineConfig({
     ecmaVersion: 2020
   },
   rules: {
+    eqeqeq: ['warn', 'always', { null: 'never' }],
     'no-debugger': ['error'],
     'no-empty': ['warn', { allowEmptyCatch: true }],
     'no-process-exit': 'off',

packages/create-vite/index.js

@@ -156,7 +156,7 @@ async function init() {
         },
         {
           type: (_, { overwrite } = {}) => {
-            if (overwrite == false) {
+            if (overwrite === false) {
               throw new Error(red('✖') + ' Operation cancelled')
             }
             return null

packages/playground/testUtils.ts

@@ -24,7 +24,7 @@ Object.keys(colors).forEach((color) => {
 
 function componentToHex(c: number): string {
   const hex = c.toString(16)
-  return hex.length == 1 ? '0' + hex : hex
+  return hex.length === 1 ? '0' + hex : hex
 }
 
 function rgbToHex(rgb: string): string {

packages/vite/src/node/optimizer/scan.ts

@@ -229,7 +229,7 @@ function esbuildScanPlugin(
             // esbuild to keep crawling due to potential side effects.
             let m
             const original = js
-            while ((m = importsRE.exec(original)) !== null) {
+            while ((m = importsRE.exec(original)) != null) {
               // This is necessary to avoid infinite loops with zero-width matches
               if (m.index === importsRE.lastIndex) {
                 importsRE.lastIndex++

packages/vite/src/node/utils.ts

@@ -206,7 +206,7 @@ export function isObject(value: unknown): value is Record<string, any> {
 }
 
 export function isDefined<T>(value: T | undefined | null): value is T {
-  return value !== undefined && value !== null
+  return value != null
 }
 
 export function lookupFile(