fix: resolve issues in Runes mode detection causing parser malfunctions (#638)

Author: baseballyama

.changeset/empty-turtles-report.md

@@ -0,0 +1,5 @@
+---
+"svelte-eslint-parser": patch
+---
+
+fix: resolve issues in Runes mode detection causing parser malfunctions

src/parser/analyze-scope.ts

@@ -191,7 +191,8 @@ export function analyzePropsScope(
         }
       }
     } else if (node.type === "VariableDeclaration") {
-      if (svelteParseContext.runes) {
+      // Process if not confirmed as non-Runes mode.
+      if (svelteParseContext.runes !== false) {
         // Process for Svelte v5 Runes props. e.g. `let { x = $bindable() } = $props()`;
         for (const decl of node.declarations) {
           if (

src/parser/globals.ts

@@ -16,15 +16,17 @@ type Global =
 export function getGlobalsForSvelte(
   svelteParseContext: SvelteParseContext,
 ): readonly Global[] {
-  if (svelteParseContext.runes) {
+  // Process if not confirmed as non-Runes mode.
+  if (svelteParseContext.runes !== false) {
     return [...globalsForSvelte, ...globalsForRunes];
   }
   return globalsForSvelte;
 }
 export function getGlobalsForSvelteScript(
   svelteParseContext: SvelteParseContext,
 ): readonly Global[] {
-  if (svelteParseContext.runes) {
+  // Process if not confirmed as non-Runes mode.
+  if (svelteParseContext.runes !== false) {
     return globalsForRunes;
   }
   return [];

src/parser/typescript/analyze/index.ts

@@ -377,7 +377,10 @@ function analyzeRuneVariables(
   ctx: VirtualTypeScriptContext,
   svelteParseContext: SvelteParseContext,
 ) {
-  if (!svelteParseContext.runes) return;
+  // No processing is needed if the user is determined not to be in Runes mode.
+  if (svelteParseContext.runes === false) {
+    return;
+  }
   const scopeManager = result.scopeManager;
   for (const globalName of globalsForRunes) {
     if (
@@ -583,7 +586,8 @@ function* analyzeDollarDerivedScopes(
   result: TSESParseForESLintResult,
   svelteParseContext: SvelteParseContext,
 ): Iterable<TransformInfo> {
-  if (!svelteParseContext.runes) return;
+  // No processing is needed if the user is determined not to be in Runes mode.
+  if (svelteParseContext.runes === false) return;
   const scopeManager = result.scopeManager;
   const derivedReferences = scopeManager.globalScope!.through.filter(
     (reference) => reference.identifier.name === "$derived",

tests/fixtures/parser/ast/svelte5/unknown-runes-mode/$props-input.svelte

@@ -0,0 +1,5 @@
+<script>
+	const { p } = $props();
+</script>
+
+<span>{p}</span>