chore: introducing @e18e/eslint-plugin

docs/_data/acknowledgements.data.ts

@@ -241,7 +241,7 @@ function groupByAuthor(dependencies: Dependency[]): Author[] {
     }
   }
 
-  return Array.from(authorMap.entries())
+  return [...authorMap.entries()]
     .map(([name, info]) => {
       const sortedPackages = info.packages.sort((a, b) =>
         a.name.localeCompare(b.name),

eslint.config.js

@@ -1,4 +1,5 @@
 // @ts-check
+import e18e from '@e18e/eslint-plugin'
 import eslint from '@eslint/js'
 import pluginImportX from 'eslint-plugin-import-x'
 import pluginN from 'eslint-plugin-n'
@@ -53,6 +54,7 @@ export default defineConfig(
     plugins: {
       n: pluginN,
       'import-x': pluginImportX,
+      e18e,
     },
     rules: {
       'n/no-exports-assign': 'error',
@@ -154,6 +156,13 @@ export default defineConfig(
       'regexp/prefer-regexp-test': 'error',
       // in some cases using explicit letter-casing is more performant than the `i` flag
       'regexp/use-ignore-case': 'off',
+      'e18e/prefer-array-at': 'error',
+      'e18e/prefer-array-fill': 'error',
+      'e18e/prefer-includes': 'error',
+      'e18e/prefer-array-to-reversed': 'error',
+      'e18e/prefer-spread-syntax': 'error',
+      'e18e/prefer-object-has-own': 'error',
+      'e18e/prefer-nullish-coalescing': 'error',
     },
   },
   {

package.json

@@ -41,6 +41,7 @@
     "merge-changelog": "tsx scripts/mergeChangelog.ts"
   },
   "devDependencies": {
+    "@e18e/eslint-plugin": "^0.8.0",
     "@eslint/js": "^9.39.5",
     "@type-challenges/utils": "^0.1.1",
     "@types/babel__core": "^7.20.5",

packages/create-vite/src/index.ts

@@ -387,7 +387,7 @@ const FRAMEWORKS: Framework[] = [
 ]
 
 const TEMPLATES = FRAMEWORKS.map((f) => f.variants.map((v) => v.name)).reduce(
-  (a, b) => a.concat(b),
+  (a, b) => [...a, ...b],
   [],
 )
 

packages/vite/rolldown.config.ts

@@ -212,9 +212,10 @@ function externalizeDepsInWatchPlugin(): Plugin {
         options.external ||= []
         if (!Array.isArray(options.external))
           throw new Error('external must be an array')
-        options.external = options.external.concat(
-          Object.keys(pkg.devDependencies),
-        )
+        options.external = [
+          ...options.external,
+          ...Object.keys(pkg.devDependencies),
+        ]
       }
     },
   }

packages/vite/rolldown.dts.config.ts

@@ -417,7 +417,7 @@ function escapeRegex(str: string): string {
 }
 
 function unique<T>(arr: T[]): T[] {
-  return Array.from(new Set(arr))
+  return [...new Set(arr)]
 }
 
 const postcssLoadConfigDeepImport =

packages/vite/rollupLicensePlugin.ts

@@ -170,7 +170,7 @@ function getDependencyInformation(dep: Dependency): DependencyInfo {
     }
   }
   if (names.size > 0) {
-    info.names = Array.from(names).join(', ')
+    info.names = [...names].join(', ')
   }
 
   if (repository) {

packages/vite/src/client/bundledDevHmrClient.ts

@@ -209,7 +209,7 @@ export class BundledDevHMRClient extends HMRClient {
         // Combined                      : [E, B, C, ACCEPTED, D, E]
         const importChain = [
           importer,
-          ...[...currentChain].reverse(),
+          ...currentChain.toReversed(),
           ...nodeChain.slice(importerIndex, -1).reverse(),
         ]
         this.logger.debug(
@@ -223,7 +223,7 @@ export class BundledDevHMRClient extends HMRClient {
         const result = this.isNodeWithinCircularImports(
           importer,
           nodeChain,
-          currentChain.concat(importer),
+          [...currentChain, importer],
           traversedModules,
         )
         if (result) return result

packages/vite/src/client/client.ts

@@ -233,9 +233,9 @@ async function handleMessage(payload: HotPayload) {
           // can't use querySelector with `[href*=]` here since the link may be
           // using relative paths so we need to use link.href to grab the full
           // URL for the include check.
-          const el = Array.from(
-            document.querySelectorAll<HTMLLinkElement>('link'),
-          ).find(
+          const el = [
+            ...document.querySelectorAll<HTMLLinkElement>('link'),
+          ].find(
             (e) =>
               !outdatedLinkTags.has(e) && cleanUrl(e.href).includes(searchUrl),
           )

packages/vite/src/module-runner/runner.ts

@@ -171,7 +171,7 @@ export class ModuleRunner {
     const meta = mod.meta!
     const moduleId = meta.id
 
-    const importee = callstack[callstack.length - 1]
+    const importee = callstack.at(-1)
 
     if (importee) mod.importers.add(importee)
 

packages/vite/src/module-runner/utils.ts

@@ -50,7 +50,7 @@ export function posixPathToFileHref(posixPath: string): string {
   if (
     (filePathLast === CHAR_FORWARD_SLASH ||
       (isWindows && filePathLast === CHAR_BACKWARD_SLASH)) &&
-    resolved[resolved.length - 1] !== '/'
+    resolved.at(-1) !== '/'
   )
     resolved += '/'
 

packages/vite/src/node/cli.ts

@@ -101,7 +101,7 @@ export const stopProfiler = (
 const filterDuplicateOptions = <T extends object>(options: T) => {
   for (const [key, value] of Object.entries(options)) {
     if (Array.isArray(value)) {
-      options[key as keyof T] = value[value.length - 1]
+      options[key as keyof T] = value.at(-1)
     }
   }
 }

packages/vite/src/node/plugins/importAnalysisBuild.ts

@@ -328,8 +328,8 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin[] {
                 if (!url) {
                   const rawUrl = code.slice(start, end)
                   if (
-                    (rawUrl[0] === `"` && rawUrl[rawUrl.length - 1] === `"`) ||
-                    (rawUrl[0] === '`' && rawUrl[rawUrl.length - 1] === '`')
+                    (rawUrl[0] === `"` && rawUrl.at(-1) === `"`) ||
+                    (rawUrl[0] === '`' && rawUrl.at(-1) === '`')
                   )
                     url = rawUrl.slice(1, -1)
                 }
@@ -429,8 +429,8 @@ export function buildImportAnalysisPlugin(config: ResolvedConfig): Plugin[] {
               if (!url) {
                 const rawUrl = code.slice(start, end)
                 if (
-                  (rawUrl[0] === `"` && rawUrl[rawUrl.length - 1] === `"`) ||
-                  (rawUrl[0] === '`' && rawUrl[rawUrl.length - 1] === '`')
+                  (rawUrl[0] === `"` && rawUrl.at(-1) === `"`) ||
+                  (rawUrl[0] === '`' && rawUrl.at(-1) === '`')
                 )
                   url = rawUrl.slice(1, -1)
               }

packages/vite/src/node/plugins/importMetaGlob.ts

@@ -262,7 +262,7 @@ export async function parseImportGlob(
     // skip invalid js code
     return []
   }
-  const matches = Array.from(cleanCode.matchAll(importGlobRE))
+  const matches = [...cleanCode.matchAll(importGlobRE)]
 
   const tasks = matches.map(async (match, index) => {
     const start = match.index!

packages/vite/src/node/plugins/resolve.ts

@@ -269,7 +269,7 @@ export function oxcResolvePlugin(
 
             mainFields: options.skipMainField
               ? options.mainFields
-              : options.mainFields.concat(['main']),
+              : [...options.mainFields, 'main'],
             conditions: options.conditions,
             externalConditions: options.externalConditions,
             extensions: options.extensions,

packages/vite/src/node/server/bundledDev.ts

@@ -518,7 +518,7 @@ class Clients {
   }
 
   getAll(): NormalizedHotChannelClient[] {
-    return Array.from(this.idToClient.values())
+    return [...this.idToClient.values()]
   }
 
   delete(client: NormalizedHotChannelClient): string | undefined {

packages/vite/src/node/server/environments/runnableEnvironment.ts

@@ -12,13 +12,8 @@ export function createRunnableDevEnvironment(
   config: ResolvedConfig,
   context: RunnableDevEnvironmentContext = {},
 ): RunnableDevEnvironment {
-  if (context.transport == null) {
-    context.transport = createServerHotChannel()
-  }
-  if (context.hot == null) {
-    context.hot = true
-  }
-
+  context.transport ??= createServerHotChannel()
+  context.hot ??= true
   return new RunnableDevEnvironment(name, config, context)
 }
 

packages/vite/src/node/server/hmr.ts

@@ -859,7 +859,7 @@ function propagateUpdate(
   }
 
   for (const importer of node.importers) {
-    const subChain = currentChain.concat(importer)
+    const subChain = [...currentChain, importer]
 
     if (importer.acceptedHmrDeps.has(node)) {
       // acceptedHmrDeps has value only for js and css
@@ -947,7 +947,7 @@ function isNodeWithinCircularImports(
         // Combined                      : [E, B, C, ACCEPTED, D, E]
         const importChain = [
           importer,
-          ...[...currentChain].reverse(),
+          ...currentChain.toReversed(),
           ...nodeChain.slice(importerIndex, -1).reverse(),
         ]
         debugHmr(
@@ -963,7 +963,7 @@ function isNodeWithinCircularImports(
       const result = isNodeWithinCircularImports(
         importer,
         nodeChain,
-        currentChain.concat(importer),
+        [...currentChain, importer],
         traversedModules,
       )
       if (result) return result

packages/vite/src/node/server/middlewares/indexHtml.ts

@@ -307,9 +307,9 @@ const devHtmlHook: IndexHtmlTransformHook = async (
       } else if (isModule && node.childNodes.length) {
         addInlineModule(node, 'js')
       } else if (node.childNodes.length) {
-        const scriptNode = node.childNodes[
-          node.childNodes.length - 1
-        ] as DefaultTreeAdapterMap['textNode']
+        const scriptNode = node.childNodes.at(
+          -1,
+        ) as DefaultTreeAdapterMap['textNode']
         for (const {
           url,
           start,

packages/vite/src/node/server/middlewares/static.ts

@@ -178,7 +178,7 @@ export function serveStaticMiddleware(
 
     const resolvedPathname = redirectedPathname || pathname
     let fileUrl = path.resolve(dir, removeLeadingSlash(resolvedPathname))
-    if (resolvedPathname.endsWith('/') && fileUrl[fileUrl.length - 1] !== '/') {
+    if (resolvedPathname.endsWith('/') && fileUrl.at(-1) !== '/') {
       fileUrl = withTrailingSlash(fileUrl)
     }
     if (redirectedPathname) {

packages/vite/src/node/server/pluginContainer.ts

@@ -636,7 +636,7 @@ class EnvironmentPluginContainer<Env extends Environment = Environment> {
   async close(): Promise<void> {
     if (this._closed) return
     this._closed = true
-    await Promise.allSettled(Array.from(this._processesing))
+    await Promise.allSettled([...this._processesing])
     const config = this.environment.getTopLevelConfig()
     let buildEndError: Error | undefined
     try {

packages/vite/src/node/server/ws.ts

@@ -461,7 +461,7 @@ export function createWebSocketServer(
 
     [isWebSocketServer]: true,
     get clients() {
-      return new Set(Array.from(wss.clients).map(getSocketClient))
+      return new Set([...wss.clients].map(getSocketClient))
     },
   }
 }

packages/vite/src/node/shortcuts.ts

@@ -67,11 +67,10 @@ export function bindCLIShortcuts<Server extends ViteDevServer | PreviewServer>(
     )
   }
 
-  const shortcuts = customShortcuts.concat(
-    (isDev
-      ? BASE_DEV_SHORTCUTS
-      : BASE_PREVIEW_SHORTCUTS) as CLIShortcut<Server>[],
-  )
+  const shortcuts = [
+    ...customShortcuts,
+    isDev ? BASE_DEV_SHORTCUTS : BASE_PREVIEW_SHORTCUTS,
+  ] as CLIShortcut<Server>[]
 
   let actionRunning = false
 

packages/vite/src/node/ssr/fetchModule.ts

@@ -141,9 +141,12 @@ function inlineSourceMap(
     code = code.replace(OTHER_SOURCE_MAP_REGEXP, '')
 
   const sourceMap = startOffset
-    ? Object.assign({}, map, {
-        mappings: ';'.repeat(startOffset) + map.mappings,
-      })
+    ? {
+        ...map,
+        ...{
+          mappings: ';'.repeat(startOffset) + map.mappings,
+        },
+      }
     : map
   result.code = `${code.trimEnd()}\n//# sourceURL=${
     mod.id

packages/vite/src/node/utils.ts

@@ -296,7 +296,7 @@ export const isJSRequest = (url: string): boolean => {
   if (knownJsSrcRE.test(url)) {
     return true
   }
-  if (!path.extname(url) && url[url.length - 1] !== '/') {
+  if (!path.extname(url) && url.at(-1) !== '/') {
     return true
   }
   return false
@@ -515,7 +515,7 @@ export function numberToPos(source: string, offset: number | Pos): Pos {
   const lines = source.slice(0, offset).split(splitRE)
   return {
     line: lines.length,
-    column: lines[lines.length - 1].length,
+    column: lines.at(-1)!.length,
   }
 }
 
@@ -946,7 +946,7 @@ export function combineSourcemaps(
 }
 
 export function unique<T>(arr: T[]): T[] {
-  return Array.from(new Set(arr))
+  return [...new Set(arr)]
 }
 
 /**
@@ -1517,6 +1517,7 @@ function mergeConfigRecursively(
       merged[key] = mergeAlias(existing, value)
       continue
     } else if (key === 'assetsInclude' && rootPath === '') {
+      // eslint-disable-next-line e18e/prefer-spread-syntax
       merged[key] = [].concat(existing, value)
       continue
     } else if (

packages/vite/src/shared/ssrTransform.ts

@@ -35,7 +35,7 @@ export function analyzeImportedModDifference(
   if (metadata?.importedNames?.length) {
     const missingBindings = metadata.importedNames.filter((s) => !(s in mod))
     if (missingBindings.length) {
-      const lastBinding = missingBindings[missingBindings.length - 1]
+      const lastBinding = missingBindings.at(-1)
 
       // For invalid named exports only, similar to how Node.js errors for top-level imports.
       // But since we transform as dynamic imports, we need to emulate the error manually.

packages/vite/src/shared/utils.ts

@@ -46,7 +46,7 @@ export function isPrimitive(value: unknown): boolean {
 }
 
 export function withTrailingSlash(path: string): string {
-  if (path[path.length - 1] !== '/') {
+  if (path.at(-1) !== '/') {
     return `${path}/`
   }
   return path

playground/css/lightningcss-plugins.js

@@ -138,8 +138,7 @@ export function nestedLikePlugin() {
                   selector[0].type === 'nesting' &&
                   selector[1].type === 'type'
                 ) {
-                  const lastParentSelectorComponent =
-                    parentSelector[parentSelector.length - 1]
+                  const lastParentSelectorComponent = parentSelector.at(-1)
                   if ('name' in lastParentSelectorComponent) {
                     const newSelector = [
                       ...parentSelector.slice(0, -1),

playground/optimize-deps/dep-cjs-with-external-deps/index.js

@@ -10,7 +10,7 @@ if (process.env.NODE_ENV === 'production') {
   }
 }
 const external = require('@vitejs/test-dep-esm-external')
-// eslint-disable-next-line no-prototype-builtins
-const externalResult = external.hasOwnProperty('foo') ? 'ok' : 'error'
+
+const externalResult = Object.hasOwn(external, 'foo') ? 'ok' : 'error'
 const externalDummyNodeBuiltinResult = `${externalDummyNodeBuiltin()} ${externalDummyNodeBuiltin.bar}`
 module.exports = { externalResult, externalDummyNodeBuiltinResult }

playground/ssr/src/circular-dep-init/module-b.js

@@ -1,7 +1,7 @@
 import { valueA } from './circular-dep-init'
 
 export const valueB = 'circ-dep-init-b'
-export const valueAB = valueA.concat(` ${valueB}`)
+export const valueAB = `${valueA} ${valueB}`
 
 export function getValueAB() {
   return valueAB

playground/test-utils.ts

@@ -393,7 +393,7 @@ export function extractSourcemap(
   read?: (filename: string) => Promise<string>,
 ): any {
   const lines = content.trim().split('\n')
-  const lastLine = lines[lines.length - 1]
+  const lastLine = lines.at(-1)
   if (read) {
     const result = fromMapFileComment(lastLine, async (url) => {
       if (url.startsWith('data:')) {