refactor (#246)

scripts/update-fixtures-ast.js

@@ -102,11 +102,11 @@ for (const name of TARGETS) {
     const servicesPath = path.join(ROOT, `${name}/services.json`)
     const source = fs.readFileSync(sourcePath, "utf8")
     const parserOptions = optionsPath ? require(optionsPath) : {}
-    const options = Object.assign(
-        { filePath: sourcePath },
-        PARSER_OPTIONS,
-        parserOptions,
-    )
+    const options = {
+        filePath: sourcePath,
+        ...PARSER_OPTIONS,
+        ...parserOptions,
+    }
     // console.log("Start:", name)
     const actual = parser.parseForESLint(source, options)
     const tokenRanges = getAllTokens(actual.ast).map((t) =>

scripts/update-fixtures-document-fragment.js

@@ -58,11 +58,12 @@ for (const name of TARGETS) {
         path.join(ROOT, `${name}/parser-options.js`),
     ].find((fp) => fs.existsSync(fp))
     const source = fs.readFileSync(sourcePath, "utf8")
-    const options = Object.assign(
-        { filePath: sourcePath },
-        PARSER_OPTIONS,
-        optionsPath ? require(optionsPath) : {},
-    )
+    const options = {
+        filePath: sourcePath,
+        ...PARSER_OPTIONS,
+        ...(optionsPath ? require(optionsPath) : {}),
+    }
+
     const result = parser.parseForESLint(source, options)
     const actual = result.services.getDocumentFragment()
 

src/ast/traverse.ts

@@ -27,6 +27,7 @@ export const KEYS = Evk.unionWith({
     VSlotScopeExpression: ["params"],
     VStartTag: ["attributes"],
     VText: [],
+    VGenericExpression: ["expression"],
 })
 
 /**
@@ -82,7 +83,7 @@ function traverse(node: Node, parent: Node | null, visitor: Visitor): void {
     visitor.enterNode(node, parent)
 
     const keys =
-        (visitor.visitorKeys || KEYS)[node.type] || getFallbackKeys(node)
+        (visitor.visitorKeys ?? KEYS)[node.type] ?? getFallbackKeys(node)
     for (i = 0; i < keys.length; ++i) {
         const child = (node as any)[keys[i]]
 

src/common/ast-utils.ts

@@ -78,8 +78,8 @@ export function isLang(
  * @returns The `lang` attribute value.
  */
 export function getLang(element: VElement | undefined): string | null {
-    const langAttr = element && element.startTag.attributes.find(isLang)
-    const lang = langAttr && langAttr.value && langAttr.value.value
+    const langAttr = element?.startTag.attributes.find(isLang)
+    const lang = langAttr?.value?.value
     return lang || null
 }
 /**

src/common/eslint-scope.ts

@@ -12,7 +12,7 @@ let escopeCache: ESLintScope | null = null
  * Load the newest `eslint-scope` from the loaded ESLint or dependency.
  */
 export function getEslintScope(): ESLintScope {
-    return escopeCache || (escopeCache = getNewest())
+    return escopeCache ?? (escopeCache = getNewest())
 }
 
 /**

src/common/espree.ts

@@ -16,7 +16,7 @@ let espreeCache: Espree | null = null
  * Gets the espree that the given ecmaVersion can parse.
  */
 export function getEspree(): Espree {
-    return espreeCache || (espreeCache = getNewestEspree())
+    return espreeCache ?? (espreeCache = getNewestEspree())
 }
 
 export function getEcmaVersionIfUseEspree(

src/common/fix-locations.ts

@@ -24,10 +24,10 @@ export function fixLocations(
 ): void {
     fixNodeLocations(result.ast, result.visitorKeys, locationCalculator)
 
-    for (const token of result.ast.tokens || []) {
+    for (const token of result.ast.tokens ?? []) {
         fixLocation(token, locationCalculator)
     }
-    for (const comment of result.ast.comments || []) {
+    for (const comment of result.ast.comments ?? []) {
         fixLocation(comment, locationCalculator)
     }
 }

src/common/location-calculator.ts

@@ -62,7 +62,7 @@ export class LocationCalculatorForHtml
         super(ltOffsets)
         this.gapOffsets = gapOffsets
         this.ltOffsets = ltOffsets
-        this.baseOffset = baseOffset || 0
+        this.baseOffset = baseOffset ?? 0
         this.baseIndexOfGap =
             this.baseOffset === 0
                 ? 0

src/external/token-store/index.ts

@@ -334,7 +334,7 @@ export default class TokenStore {
             )
             .getOneToken()
 
-        if (token && token.range[0] === offset) {
+        if (token?.range[0] === offset) {
             return token
         }
         return null

src/html/intermediate-tokenizer.ts

@@ -222,7 +222,7 @@ export class IntermediateTokenizer {
     private processComment(token: Token): IntermediateToken | null {
         this.comments.push(token)
 
-        if (this.currentToken != null && this.currentToken.type === "Text") {
+        if (this.currentToken?.type === "Text") {
             return this.commit()
         }
         return null

src/html/parser.ts

@@ -421,7 +421,7 @@ export class Parser {
 
         if (name === "template") {
             const xmlns = token.attributes.find((a) => a.key.name === "xmlns")
-            const value = xmlns && xmlns.value && xmlns.value.value
+            const value = xmlns?.value?.value
 
             if (value === NS.HTML || value === NS.MathML || value === NS.SVG) {
                 return value
@@ -477,7 +477,7 @@ export class Parser {
 
         node.key.name = adjustAttributeName(node.key.name, namespace)
         const key = this.getTagName(node.key)
-        const value = node.value && node.value.value
+        const value = node.value?.value
 
         if (key === "xmlns" && value !== namespace) {
             this.reportParseError(node, "x-invalid-namespace")
@@ -616,8 +616,7 @@ export class Parser {
             for (const attribute of element.startTag.attributes) {
                 if (attribute.directive) {
                     if (
-                        attribute.key.argument != null &&
-                        attribute.key.argument.type === "VExpressionContainer"
+                        attribute.key.argument?.type === "VExpressionContainer"
                     ) {
                         resolveReferences(attribute.key.argument)
                     }

src/html/tokenizer.ts

@@ -980,8 +980,7 @@ export class Tokenizer {
         function maybeValidCustomBlock(this: Tokenizer, nextCp: number) {
             return (
                 this.currentToken &&
-                this.lastTagOpenToken &&
-                this.lastTagOpenToken.value.startsWith(
+                this.lastTagOpenToken?.value.startsWith(
                     this.currentToken.value + String.fromCodePoint(nextCp),
                 )
             )

src/index.ts

@@ -49,15 +49,13 @@ export function parseForESLint(
     code: string,
     parserOptions: any,
 ): AST.ESLintExtendedProgram {
-    const options: ParserOptions = Object.assign(
-        {
-            comment: true,
-            loc: true,
-            range: true,
-            tokens: true,
-        },
-        parserOptions || {},
-    )
+    const options: ParserOptions = {
+        comment: true,
+        loc: true,
+        range: true,
+        tokens: true,
+        ...(parserOptions ?? {}),
+    }
 
     let result: AST.ESLintExtendedProgram
     let document: AST.VDocumentFragment | null
@@ -70,12 +68,12 @@ export function parseForESLint(
         ;({ result, document, locationCalculator } = parseAsSFC(code, options))
     }
 
-    result.services = Object.assign(
-        result.services || {},
-        services.define(code, result.ast, document, locationCalculator, {
+    result.services = {
+        ...(result.services || {}),
+        ...services.define(code, result.ast, document, locationCalculator, {
             parserOptions: options,
         }),
-    )
+    }
 
     return result
 }
@@ -96,7 +94,7 @@ export { AST }
 function parseAsSFC(code: string, options: ParserOptions) {
     const optionsForTemplate = {
         ...options,
-        ecmaVersion: options.ecmaVersion || DEFAULT_ECMA_VERSION,
+        ecmaVersion: options.ecmaVersion ?? DEFAULT_ECMA_VERSION,
     }
     const skipParsingScript = options.parser === false
     const tokenizer = new HTMLTokenizer(code, optionsForTemplate)
@@ -128,7 +126,7 @@ function parseAsSFC(code: string, options: ParserOptions) {
     if (skipParsingScript || !scripts.length) {
         result = parseScript("", {
             ...options,
-            ecmaVersion: options.ecmaVersion || DEFAULT_ECMA_VERSION,
+            ecmaVersion: options.ecmaVersion ?? DEFAULT_ECMA_VERSION,
             parser: scriptParser,
         })
     } else if (
@@ -195,7 +193,7 @@ function parseAsSFC(code: string, options: ParserOptions) {
 function parseAsScript(code: string, options: ParserOptions) {
     return parseScript(code, {
         ...options,
-        ecmaVersion: options.ecmaVersion || DEFAULT_ECMA_VERSION,
+        ecmaVersion: options.ecmaVersion ?? DEFAULT_ECMA_VERSION,
         parser: getScriptParser(options.parser, () => {
             const ext = (
                 path.extname(options.filePath || "unknown.js").toLowerCase() ||

src/parser-services.ts

@@ -341,7 +341,7 @@ export function define(
                                 )
                                 // Register handlers into the intermediate event emitter.
                                 for (const selector of Object.keys(
-                                    visitor || {},
+                                    visitor ?? {},
                                 )) {
                                     emitter.on(selector, visitor![selector])
                                 }

src/script-setup/index.ts

@@ -216,7 +216,7 @@ export function parseScriptSetupElements(
 ): ESLintExtendedProgram {
     const parserOptions: ParserOptions = {
         ...originalParserOptions,
-        ecmaVersion: originalParserOptions.ecmaVersion || DEFAULT_ECMA_VERSION,
+        ecmaVersion: originalParserOptions.ecmaVersion ?? DEFAULT_ECMA_VERSION,
     }
     const scriptSetupModuleCodeBlocks = getScriptSetupModuleCodeBlocks(
         scriptSetupElement,
@@ -323,7 +323,7 @@ export function parseScriptSetupElements(
                 const textNode = node.children[0]
                 return Math.min(
                     start,
-                    textNode != null && textNode.type === "VText"
+                    textNode?.type === "VText"
                         ? textNode.range[0]
                         : node.startTag.range[1],
                 )
@@ -344,7 +344,7 @@ export function parseScriptSetupElements(
                 const textNode = node.children[0]
                 return Math.max(
                     end,
-                    textNode != null && textNode.type === "VText"
+                    textNode?.type === "VText"
                         ? textNode.range[1]
                         : (node.endTag?.range[0] ?? node.range[1]),
                 )
@@ -575,7 +575,7 @@ function getScriptSetupCodeBlocks(
             (t) => t.range[0] === body.range[0],
         )
         const exportToken = tokens[exportTokenIndex]
-        if (exportToken && exportToken.value === "export") {
+        if (exportToken?.value === "export") {
             // Consume code up to the start position of `export`.
             // The code may contain legacy decorators.
             append(statementCodeBlocks, usedOffset, exportToken.range[0])
@@ -958,7 +958,7 @@ function remapLocationAndTokens(
     { codeBlocks }: ScriptSetupModuleCodeBlocks,
     locationCalculator: LocationCalculator,
 ) {
-    const tokens = result.ast.tokens || []
+    const tokens = result.ast.tokens ?? []
 
     const endMap = new Map<number, number>()
     const buffer: number[] = []

src/script-setup/scope-analyzer.ts

@@ -131,7 +131,7 @@ function extractVariables(scopeManager: escopeTypes.ScopeManager) {
     const moduleScope = globalScope.childScopes.find(
         (scope) => scope.type === "module",
     )
-    for (const variable of (moduleScope && moduleScope.variables) || []) {
+    for (const variable of moduleScope?.variables ?? []) {
         scriptVariables.set(variable.name, variable)
     }
     return scriptVariables