feat(lint): add type-aware rules

package.json

@@ -13,7 +13,8 @@
     "size-esm-runtime": "node scripts/build.js vue -f esm-bundler-runtime",
     "size-esm": "node scripts/build.js runtime-dom runtime-core reactivity shared -f esm-bundler",
     "check": "tsc --incremental --noEmit",
-    "lint": "eslint --cache .",
+    "lint": "tsslint --project tsconfig.json",
+    "lint-types": "npm run lint -- --type-aware",
     "format": "prettier --write --cache .",
     "format-check": "prettier --check --cache .",
     "test": "vitest",
@@ -54,7 +55,7 @@
       "prettier --write"
     ],
     "*.ts?(x)": [
-      "eslint --fix",
+      "npm run lint -- --fix",
       "prettier --parser=typescript --write"
     ]
   },
@@ -70,19 +71,22 @@
     "@rollup/plugin-node-resolve": "^15.3.0",
     "@rollup/plugin-replace": "5.0.4",
     "@swc/core": "^1.9.3",
+    "@tsslint/cli": "~1.4.6",
+    "@tsslint/config": "~1.4.6",
+    "@tsslint/eslint": "~1.4.6",
     "@types/hash-sum": "^1.0.2",
     "@types/node": "^22.10.1",
     "@types/semver": "^7.5.8",
     "@types/serve-handler": "^6.1.4",
+    "@typescript-eslint/eslint-plugin": "^8.17.0",
     "@vitest/coverage-v8": "^2.1.5",
+    "@vitest/eslint-plugin": "^1.1.14",
     "@vue/consolidate": "1.0.0",
     "conventional-changelog-cli": "^5.0.0",
     "enquirer": "^2.4.1",
     "esbuild": "^0.24.0",
     "esbuild-plugin-polyfill-node": "^0.3.0",
-    "eslint": "^9.15.0",
-    "eslint-plugin-import-x": "^4.4.2",
-    "@vitest/eslint-plugin": "^1.1.10",
+    "eslint-plugin-import-x": "^4.4.3",
     "estree-walker": "catalog:",
     "jsdom": "^25.0.1",
     "lint-staged": "^15.2.10",
@@ -108,19 +112,7 @@
     "todomvc-app-css": "^2.4.3",
     "tslib": "^2.8.1",
     "typescript": "~5.6.2",
-    "typescript-eslint": "^8.14.0",
     "vite": "catalog:",
     "vitest": "^2.1.5"
-  },
-  "pnpm": {
-    "peerDependencyRules": {
-      "allowedVersions": {
-        "typescript-eslint>eslint": "^9.0.0",
-        "@typescript-eslint/eslint-plugin>eslint": "^9.0.0",
-        "@typescript-eslint/parser>eslint": "^9.0.0",
-        "@typescript-eslint/type-utils>eslint": "^9.0.0",
-        "@typescript-eslint/utils>eslint": "^9.0.0"
-      }
-    }
   }
 }

packages/compiler-core/__tests__/parse.spec.ts

@@ -114,7 +114,7 @@ describe('compiler: parse', () => {
     test('text with mix of tags and interpolations', () => {
       const ast = baseParse('some <span>{{ foo < bar + foo }} text</span>')
       const text1 = ast.children[0] as TextNode
-      const text2 = (ast.children[1] as ElementNode).children![1] as TextNode
+      const text2 = (ast.children[1] as ElementNode).children[1] as TextNode
 
       expect(text1).toStrictEqual({
         type: NodeTypes.TEXT,

packages/compiler-core/__tests__/transforms/vIf.spec.ts

@@ -97,8 +97,8 @@ describe('compiler: v-if', () => {
       // #2058 since a component may fail to resolve and fallback to a plain
       // element, it still needs to be made a block
       expect(
-        ((node.branches[0].children[0] as ElementNode)!
-          .codegenNode as VNodeCall)!.isBlock,
+        ((node.branches[0].children[0] as ElementNode).codegenNode as VNodeCall)
+          .isBlock,
       ).toBe(true)
     })
 
@@ -702,8 +702,7 @@ describe('compiler: v-if', () => {
       expect(b1b1.children[0].type).toBe(NodeTypes.COMMENT)
       expect((b1b1.children[0] as CommentNode).content).toBe('comment2')
 
-      const b1b2: IfBranchNode = (b1.children[1] as IfNode)
-        .branches[1] as IfBranchNode
+      const b1b2: IfBranchNode = (b1.children[1] as IfNode).branches[1]
       expect(b1b2.children[0].type).toBe(NodeTypes.COMMENT)
       expect((b1b2.children[0] as CommentNode).content).toBe(`comment3`)
       expect(b1b2.children[1].type).toBe(NodeTypes.ELEMENT)

packages/compiler-core/src/codegen.ts

@@ -768,8 +768,8 @@ function genCompoundExpression(
   node: CompoundExpressionNode,
   context: CodegenContext,
 ) {
-  for (let i = 0; i < node.children!.length; i++) {
-    const child = node.children![i]
+  for (let i = 0; i < node.children.length; i++) {
+    const child = node.children[i]
     if (isString(child)) {
       context.push(child, NewlineType.Unknown)
     } else {

packages/compiler-core/src/parser.ts

@@ -324,15 +324,15 @@ const tokenizer = new Tokenizer(stack, {
           // assign value
 
           // condense whitespaces in class
-          if (currentProp!.name === 'class') {
+          if (currentProp.name === 'class') {
             currentAttrValue = condense(currentAttrValue).trim()
           }
 
           if (quote === QuoteType.Unquoted && !currentAttrValue) {
             emitError(ErrorCodes.MISSING_ATTRIBUTE_VALUE, end)
           }
 
-          currentProp!.value = {
+          currentProp.value = {
             type: NodeTypes.TEXT,
             content: currentAttrValue,
             loc:

packages/compiler-core/src/transform.ts

@@ -318,7 +318,7 @@ export function createTransformContext(
     if (identifiers[id] === undefined) {
       identifiers[id] = 0
     }
-    identifiers[id]!++
+    identifiers[id]++
   }
 
   function removeId(id: string) {

packages/compiler-core/src/transforms/transformExpression.ts

@@ -33,12 +33,7 @@ import {
   makeMap,
 } from '@vue/shared'
 import { ErrorCodes, createCompilerError } from '../errors'
-import type {
-  AssignmentExpression,
-  Identifier,
-  Node,
-  UpdateExpression,
-} from '@babel/types'
+import type { Identifier, Node } from '@babel/types'
 import { validateBrowserExpression } from '../validateExpression'
 import { parseExpression } from '@babel/parser'
 import { IS_REF, UNREF } from '../runtimeHelpers'
@@ -169,7 +164,7 @@ export function processExpression(
           // let is a local non-ref value, and we need to replicate the
           // right hand side value.
           // x = y --> isRef(x) ? x.value = y : x = y
-          const { right: rVal, operator } = parent as AssignmentExpression
+          const { right: rVal, operator } = parent
           const rExp = rawExp.slice(rVal.start! - 1, rVal.end! - 1)
           const rExpString = stringifyExpression(
             processExpression(
@@ -186,9 +181,9 @@ export function processExpression(
         } else if (isUpdateArg) {
           // make id replace parent in the code range so the raw update operator
           // is removed
-          id!.start = parent!.start
-          id!.end = parent!.end
-          const { prefix: isPrefix, operator } = parent as UpdateExpression
+          id.start = parent.start
+          id.end = parent.end
+          const { prefix: isPrefix, operator } = parent
           const prefix = isPrefix ? operator : ``
           const postfix = isPrefix ? `` : operator
           // let binding.

packages/compiler-core/src/transforms/vFor.ts

@@ -18,7 +18,6 @@ import {
   type PlainElementNode,
   type RenderSlotCall,
   type SimpleExpressionNode,
-  type SlotOutletNode,
   type VNodeCall,
   createBlockStatement,
   createCallExpression,
@@ -159,7 +158,7 @@ export const transformFor: NodeTransform = createStructuralDirectiveTransform(
           : isTemplate &&
               node.children.length === 1 &&
               isSlotOutlet(node.children[0])
-            ? (node.children[0] as SlotOutletNode) // api-extractor somehow fails to infer this
+            ? node.children[0] // api-extractor somehow fails to infer this
             : null
 
         if (slotOutlet) {

packages/compiler-core/src/transforms/vIf.ts

@@ -290,9 +290,7 @@ function createChildrenCodegenNode(
       )
     }
   } else {
-    const ret = (firstChild as ElementNode).codegenNode as
-      | BlockCodegenNode
-      | MemoExpression
+    const ret = firstChild.codegenNode as BlockCodegenNode | MemoExpression
     const vnodeCall = getMemoedVNodeCall(ret)
     // Change createVNode to createBlock.
     if (vnodeCall.type === NodeTypes.VNODE_CALL) {

packages/compiler-dom/__tests__/parse.spec.ts

@@ -131,7 +131,7 @@ describe('DOM parser', () => {
 
     test('CDATA', () => {
       const ast = parse('<svg><![CDATA[some text]]></svg>', parserOptions)
-      const text = (ast.children[0] as ElementNode).children![0] as TextNode
+      const text = (ast.children[0] as ElementNode).children[0] as TextNode
 
       expect(text).toStrictEqual({
         type: NodeTypes.TEXT,

packages/compiler-dom/src/decodeHtmlBrowser.ts

@@ -1,9 +1,8 @@
-/* eslint-disable no-restricted-globals */
-
 let decoder: HTMLDivElement
 
 export function decodeHtmlBrowser(raw: string, asAttr = false): string {
   if (!decoder) {
+    // eslint-disable-next-line no-restricted-globals
     decoder = document.createElement('div')
   }
   if (asAttr) {

packages/compiler-dom/src/transforms/vOn.ts

@@ -61,9 +61,7 @@ const resolveModifiers = (
       // runtimeModifiers: modifiers that needs runtime guards
       if (maybeKeyModifier(modifier)) {
         if (isStaticExp(key)) {
-          if (
-            isKeyboardEvent((key as SimpleExpressionNode).content.toLowerCase())
-          ) {
+          if (isKeyboardEvent(key.content.toLowerCase())) {
             keyModifiers.push(modifier)
           } else {
             nonKeyModifiers.push(modifier)

packages/compiler-sfc/__tests__/compileTemplate.spec.ts

@@ -4,7 +4,7 @@ import {
   type SFCTemplateCompileOptions,
   compileTemplate,
 } from '../src/compileTemplate'
-import { type SFCTemplateBlock, parse } from '../src/parse'
+import { parse } from '../src/parse'
 import { compileScript } from '../src'
 
 function compile(opts: Omit<SFCTemplateCompileOptions, 'id'>) {
@@ -52,7 +52,7 @@ body
 </template>
 `,
     { filename: 'example.vue', sourceMap: true },
-  ).descriptor.template as SFCTemplateBlock
+  ).descriptor.template!
 
   const result = compile({
     filename: 'example.vue',
@@ -76,7 +76,7 @@ test('preprocess pug with indents and blank lines', () => {
 </template>
 `,
     { filename: 'example.vue', sourceMap: true },
-  ).descriptor.template as SFCTemplateBlock
+  ).descriptor.template!
 
   const result = compile({
     filename: 'example.vue',
@@ -94,7 +94,7 @@ test('warn missing preprocessor', () => {
   const template = parse(`<template lang="unknownLang">hi</template>\n`, {
     filename: 'example.vue',
     sourceMap: true,
-  }).descriptor.template as SFCTemplateBlock
+  }).descriptor.template!
 
   const result = compile({
     filename: 'example.vue',
@@ -337,7 +337,7 @@ test('preprocessor errors', () => {
 </template>
 `,
     { filename: 'example.vue', sourceMap: true },
-  ).descriptor.template as SFCTemplateBlock
+  ).descriptor.template!
 
   const result = compile({
     filename: 'example.vue',

packages/compiler-sfc/__tests__/parse.spec.ts

@@ -81,7 +81,7 @@ font-weight: bold;
 
       const consumer = new SourceMapConsumer(script!.map!)
       consumer.eachMapping(mapping => {
-        expect(mapping.originalLine - mapping.generatedLine).toBe(padding)
+        expect(mapping.originalLine! - mapping.generatedLine).toBe(padding)
       })
     })
 
@@ -100,8 +100,8 @@ font-weight: bold;
 
       const consumer = new SourceMapConsumer(template.map!)
       consumer.eachMapping(mapping => {
-        expect(mapping.originalLine - mapping.generatedLine).toBe(padding)
-        expect(mapping.originalColumn - mapping.generatedColumn).toBe(2)
+        expect(mapping.originalLine! - mapping.generatedLine).toBe(padding)
+        expect(mapping.originalColumn! - mapping.generatedColumn).toBe(2)
       })
     })
 
@@ -111,11 +111,11 @@ font-weight: bold;
         `${'\n'.repeat(padding)}<i18n>\n{\n  "greeting": "hello"\n}\n</i18n>\n`,
       ).descriptor.customBlocks[0]
 
-      expect(custom!.map).not.toBeUndefined()
+      expect(custom.map).not.toBeUndefined()
 
-      const consumer = new SourceMapConsumer(custom!.map!)
+      const consumer = new SourceMapConsumer(custom.map!)
       consumer.eachMapping(mapping => {
-        expect(mapping.originalLine - mapping.generatedLine).toBe(padding)
+        expect(mapping.originalLine! - mapping.generatedLine).toBe(padding)
       })
     })
   })

packages/compiler-sfc/src/compileScript.ts

@@ -1138,7 +1138,7 @@ function walkDeclaration(
     isAllLiteral = node.members.every(
       member => !member.initializer || isStaticNode(member.initializer),
     )
-    bindings[node.id!.name] = isAllLiteral
+    bindings[node.id.name] = isAllLiteral
       ? BindingTypes.LITERAL_CONST
       : BindingTypes.SETUP_CONST
   } else if (

packages/compiler-sfc/src/compileTemplate.ts

@@ -289,7 +289,7 @@ function mapLines(oldMap: RawSourceMap, newMap: RawSourceMap): RawSourceMap {
 
     const origPosInOldMap = oldMapConsumer.originalPositionFor({
       line: m.originalLine,
-      column: m.originalColumn,
+      column: m.originalColumn!,
     })
 
     if (origPosInOldMap.source == null) {
@@ -305,7 +305,7 @@ function mapLines(oldMap: RawSourceMap, newMap: RawSourceMap): RawSourceMap {
         line: origPosInOldMap.line, // map line
         // use current column, since the oldMap produced by @vue/compiler-sfc
         // does not
-        column: m.originalColumn,
+        column: m.originalColumn!,
       },
       source: origPosInOldMap.source,
       name: origPosInOldMap.name,

packages/compiler-sfc/src/script/context.ts

@@ -136,7 +136,7 @@ export class ScriptCompileContext {
 
     this.scriptSetupAst =
       descriptor.scriptSetup &&
-      parse(descriptor.scriptSetup!.content, this.startOffset!)
+      parse(descriptor.scriptSetup.content, this.startOffset!)
   }
 
   getString(node: Node, scriptSetup = true): string {

packages/compiler-sfc/src/script/definePropsDestructure.ts

@@ -278,7 +278,7 @@ export function transformDestructuredProps(
 
       if (node.type === 'Identifier') {
         if (
-          isReferencedIdentifier(node, parent!, parentStack) &&
+          isReferencedIdentifier(node, parent, parentStack) &&
           !excludedIds.has(node)
         ) {
           if (currentScope[node.name]) {

packages/compiler-sfc/src/script/resolveType.ts

@@ -1349,7 +1349,7 @@ function recordType(
       if (existing) {
         if (node.type === 'TSModuleDeclaration') {
           if (existing.type === 'TSModuleDeclaration') {
-            mergeNamespaces(existing as typeof node, node)
+            mergeNamespaces(existing, node)
           } else {
             attachNamespace(existing, node)
           }

packages/compiler-sfc/src/style/preprocessors.ts

@@ -61,7 +61,7 @@ const scss: StylePreprocessor = (source, map, options, load = require) => {
         code: css,
         errors: [],
         dependencies,
-        map: merge(map, sourceMap!),
+        map: merge(map, sourceMap),
       }
     }
     return { code: css, errors: [], dependencies }

packages/reactivity/__tests__/collections/Set.spec.ts

@@ -44,7 +44,7 @@ describe('reactivity/collections', () => {
 
     it('should observe for of iteration', () => {
       let dummy
-      const set = reactive(new Set() as Set<number>)
+      const set = reactive(new Set<number>())
       effect(() => {
         dummy = 0
         for (let num of set) {
@@ -82,7 +82,7 @@ describe('reactivity/collections', () => {
 
     it('should observe values iteration', () => {
       let dummy
-      const set = reactive(new Set() as Set<number>)
+      const set = reactive(new Set<number>())
       effect(() => {
         dummy = 0
         for (let num of set.values()) {
@@ -102,7 +102,7 @@ describe('reactivity/collections', () => {
 
     it('should observe keys iteration', () => {
       let dummy
-      const set = reactive(new Set() as Set<number>)
+      const set = reactive(new Set<number>())
       effect(() => {
         dummy = 0
         for (let num of set.keys()) {