feat: makes it optional whether to parse runes. (#536)

.changeset/shy-cups-visit.md

@@ -0,0 +1,5 @@
+---
+"svelte-eslint-parser": minor
+---
+
+feat: makes it optional whether to parse runes.

README.md

@@ -245,9 +245,34 @@ For example in `.eslintrc.*`:
 }
 ```
 
+### parserOptions.svelteConfig
+
+If you are using `eslint.config.js`, you can provide a `svelte.config.js` in the `parserOptions.svelteConfig` property.
+
+For example:
+
+```js
+import svelteConfig from "./svelte.config.js";
+export default [
+  {
+    files: ["**/*.svelte", "*.svelte"],
+    languageOptions: {
+      parser: svelteParser,
+      parserOptions: {
+        svelteConfig: svelteConfig,
+      },
+    },
+  },
+];
+```
+
+If `parserOptions.svelteConfig` is not specified, some config will be statically parsed from the `svelte.config.js` file.
+
+The `.eslintrc.*` style configuration cannot load `svelte.config.js` because it cannot use ESM. We recommend using the `eslint.config.js` style configuration.
+
 ### parserOptions.svelteFeatures
 
-You can use `parserOptions.svelteFeatures` property to specify how to parse related to Svelte features. For example:
+You can use `parserOptions.svelteFeatures` property to specify how to parse related to Svelte features.
 
 For example in `eslint.config.js`:
 
@@ -259,6 +284,12 @@ export default [
       parser: svelteParser,
       parserOptions: {
         svelteFeatures: {
+          /* -- Experimental Svelte Features -- */
+          /* It may be changed or removed in minor versions without notice. */
+          // If true, it will analyze Runes.
+          // By default, it will try to read `compilerOptions.runes` from `svelte.config.js`.
+          // However, note that if `parserOptions.svelteConfig` is not specified and the file cannot be parsed by static analysis, it will behave as `false`.
+          runes: false,
           /* -- Experimental Svelte Features -- */
           /* It may be changed or removed in minor versions without notice. */
           // Whether to parse the `generics` attribute.
@@ -278,6 +309,12 @@ For example in `.eslintrc.*`:
   "parser": "svelte-eslint-parser",
   "parserOptions": {
     "svelteFeatures": {
+      /* -- Experimental Svelte Features -- */
+      /* It may be changed or removed in minor versions without notice. */
+      // If true, it will analyze Runes.
+      // By default, it will try to read `compilerOptions.runes` from `svelte.config.js`.
+      // However, note that if the file cannot be parsed by static analysis, it will behave as false.
+      "runes": false,
       /* -- Experimental Svelte Features -- */
       /* It may be changed or removed in minor versions without notice. */
       // Whether to parse the `generics` attribute.
@@ -292,20 +329,22 @@ For example in `.eslintrc.*`:
 
 **_This is an experimental feature. It may be changed or removed in minor versions without notice._**
 
-If you install Svelte v5 the parser will be able to parse runes, and will also be able to parse `*.js` and `*.ts` files.
+If you install Svelte v5 and turn on runes (`compilerOptions.runes` in `svelte.config.js` or `parserOptions.svelteFeatures.runes` in ESLint config is `true`), the parser will be able to parse runes, and will also be able to parse `*.js` and `*.ts` files.
 
 When using this mode in an ESLint configuration, it is recommended to set it per file pattern as below.
 
 For example in `eslint.config.js`:
 
 ```js
+import svelteConfig from "./svelte.config.js";
 export default [
   {
     files: ["**/*.svelte", "*.svelte"],
     languageOptions: {
       parser: svelteParser,
       parserOptions: {
         parser: "...",
+        svelteConfig,
         /* ... */
       },
     },
@@ -315,6 +354,7 @@ export default [
     languageOptions: {
       parser: svelteParser,
       parserOptions: {
+        svelteConfig,
         /* ... */
       },
     },
@@ -325,6 +365,7 @@ export default [
       parser: svelteParser,
       parserOptions: {
         parser: "...(ts parser)...",
+        svelteConfig,
         /* ... */
       },
     },
@@ -342,13 +383,15 @@ For example in `.eslintrc.*`:
       "parser": "svelte-eslint-parser",
       "parserOptions": {
         "parser": "...",
+        "svelteFeatures": { "runes": true },
         /* ... */
       },
     },
     {
       "files": ["*.svelte.js"],
       "parser": "svelte-eslint-parser",
       "parserOptions": {
+        "svelteFeatures": { "runes": true },
         /* ... */
       },
     },
@@ -357,6 +400,7 @@ For example in `.eslintrc.*`:
       "parser": "svelte-eslint-parser",
       "parserOptions": {
         "parser": "...(ts parser)...",
+        "svelteFeatures": { "runes": true },
         /* ... */
       },
     },

src/index.ts

@@ -4,14 +4,15 @@ import { KEYS } from "./visitor-keys";
 import { ParseError } from "./errors";
 export {
   parseForESLint,
-  StyleContext,
-  StyleContextNoStyleElement,
-  StyleContextParseError,
-  StyleContextSuccess,
-  StyleContextUnknownLang,
+  type StyleContext,
+  type StyleContextNoStyleElement,
+  type StyleContextParseError,
+  type StyleContextSuccess,
+  type StyleContextUnknownLang,
 } from "./parser";
 export * as meta from "./meta";
 export { name } from "./meta";
+export type { SvelteConfig } from "./svelte-config";
 
 export { AST, ParseError };
 

src/parser/analyze-scope.ts

@@ -10,6 +10,7 @@ import type {
 import { addReference, addVariable, getScopeFromNode } from "../scope";
 import { addElementToSortedArray } from "../utils";
 import type { NormalizedParserOptions } from "./parser-options";
+import type { SvelteParseContext } from "./svelte-parse-context";
 /**
  * Analyze scope
  */
@@ -160,6 +161,7 @@ export function analyzeStoreScope(scopeManager: ScopeManager): void {
 export function analyzePropsScope(
   body: SvelteScriptElement,
   scopeManager: ScopeManager,
+  svelteParseContext: SvelteParseContext,
 ): void {
   const moduleScope = scopeManager.scopes.find(
     (scope) => scope.type === "module",
@@ -187,23 +189,25 @@ export function analyzePropsScope(
         }
       }
     } else if (node.type === "VariableDeclaration") {
-      // Process for Svelte v5 Runes props. e.g. `let { x = $bindable() } = $props()`;
-      for (const decl of node.declarations) {
-        if (
-          decl.init?.type === "CallExpression" &&
-          decl.init.callee.type === "Identifier" &&
-          decl.init.callee.name === "$props" &&
-          decl.id.type === "ObjectPattern"
-        ) {
-          for (const pattern of extractPattern(decl.id)) {
-            if (
-              pattern.type === "AssignmentPattern" &&
-              pattern.left.type === "Identifier" &&
-              pattern.right.type === "CallExpression" &&
-              pattern.right.callee.type === "Identifier" &&
-              pattern.right.callee.name === "$bindable"
-            ) {
-              addPropReference(pattern.left, moduleScope);
+      if (svelteParseContext.runes) {
+        // Process for Svelte v5 Runes props. e.g. `let { x = $bindable() } = $props()`;
+        for (const decl of node.declarations) {
+          if (
+            decl.init?.type === "CallExpression" &&
+            decl.init.callee.type === "Identifier" &&
+            decl.init.callee.name === "$props" &&
+            decl.id.type === "ObjectPattern"
+          ) {
+            for (const pattern of extractPattern(decl.id)) {
+              if (
+                pattern.type === "AssignmentPattern" &&
+                pattern.left.type === "Identifier" &&
+                pattern.right.type === "CallExpression" &&
+                pattern.right.callee.type === "Identifier" &&
+                pattern.right.callee.name === "$bindable"
+              ) {
+                addPropReference(pattern.left, moduleScope);
+              }
             }
           }
         }

src/parser/globals.ts

@@ -1,6 +1,6 @@
-import { svelteVersion } from "./svelte-version";
+import type { SvelteParseContext } from "./svelte-parse-context";
 
-const globalsForSvelte4 = ["$$slots", "$$props", "$$restProps"] as const;
+const globalsForSvelte = ["$$slots", "$$props", "$$restProps"] as const;
 export const globalsForRunes = [
   "$state",
   "$derived",
@@ -10,10 +10,22 @@ export const globalsForRunes = [
   "$inspect",
   "$host",
 ] as const;
-const globalsForSvelte5 = [...globalsForSvelte4, ...globalsForRunes];
-export const globals = svelteVersion.gte(5)
-  ? globalsForSvelte5
-  : globalsForSvelte4;
-export const globalsForSvelteScript = svelteVersion.gte(5)
-  ? globalsForRunes
-  : [];
+type Global =
+  | (typeof globalsForSvelte)[number]
+  | (typeof globalsForRunes)[number];
+export function getGlobalsForSvelte(
+  svelteParseContext: SvelteParseContext,
+): readonly Global[] {
+  if (svelteParseContext.runes) {
+    return [...globalsForSvelte, ...globalsForRunes];
+  }
+  return globalsForSvelte;
+}
+export function getGlobalsForSvelteScript(
+  svelteParseContext: SvelteParseContext,
+): readonly Global[] {
+  if (svelteParseContext.runes) {
+    return globalsForRunes;
+  }
+  return [];
+}