feat: Support runes (#425)

.changeset/blue-pets-play.md

@@ -0,0 +1,5 @@
+---
+"svelte-eslint-parser": minor
+---
+
+feat: Support runes

.eslintignore

@@ -4,6 +4,8 @@
 /node_modules
 /tests/fixtures/**/*.json
 /tests/fixtures/**/*.svelte
+/tests/fixtures/**/*.js
+/tests/fixtures/**/*.ts
 /explorer/dist
 /explorer/node_modules
 /explorer-v2/build

.eslintrc.js

@@ -20,7 +20,7 @@ module.exports = {
     "no-lonely-if": "off",
     "no-shadow": "off",
     "no-warning-comments": "warn",
-    "require-jsdoc": "error",
+    "require-jsdoc": "off",
     "prettier/prettier": [
       "error",
       {},

.github/workflows/NodeCI.yml

@@ -35,13 +35,27 @@ jobs:
         run: pnpm install
       - name: Test
         run: pnpm run test
-  test-for-svelte-v4:
+  test-for-svelte-v5:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: pnpm/action-setup@v2
       - name: Use Node.js
         uses: actions/setup-node@v4
+      - name: Install Packages
+        run: pnpm install
+      - name: Test
+        run: pnpm run test
+
+  test-for-svelte-v4:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pnpm/action-setup@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
       - name: Install Svelte v4
         run: |+
           pnpm install -D svelte@4
@@ -50,6 +64,7 @@ jobs:
         run: pnpm install
       - name: Test
         run: pnpm run test
+
   test-for-svelte-v3:
     runs-on: ubuntu-latest
     strategy:
@@ -138,12 +153,17 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version: 18
+      - name: Install Svelte v4
+        run: |+
+          pnpm install -D svelte@4
+          rm -rf node_modules
       - name: Install Packages
         run: pnpm install
       - name: Update fixtures
         run: pnpm run update-fixtures
       - name: Check changes
         run: |
+          git checkout package.json && \
           git add --all && \
           git diff-index --cached HEAD --stat --exit-code
   test-and-coverage:

benchmark/index.ts

@@ -1,5 +1,5 @@
 // eslint-disable-next-line eslint-comments/disable-enable-pair -- ignore
-/* eslint-disable require-jsdoc, no-console -- ignore */
+/* eslint-disable no-console -- ignore */
 import * as Benchmark from "benchmark";
 import fs from "fs";
 import { parseForESLint } from "../src/index";

explorer-v2/package.json

@@ -18,7 +18,7 @@
 		"eslint-scope": "^7.0.0",
 		"esquery": "^1.5.0",
 		"pako": "^2.0.3",
-		"svelte": "^4.0.0",
+		"svelte": "^5.0.0-next.2",
 		"svelte-eslint-parser": "link:..",
 		"tslib": "^2.5.0"
 	},

src/parser/globals.ts

@@ -0,0 +1,16 @@
+import { VERSION as SVELTE_VERSION } from "svelte/compiler";
+
+const globalsForSvelte4: Readonly<string[]> = [
+  "$$slots",
+  "$$props",
+  "$$restProps",
+] as const;
+export const globalsForSvelte5 = [
+  "$state",
+  "$derived",
+  "$effect",
+  "$props",
+] as const;
+export const globals = SVELTE_VERSION.startsWith("5")
+  ? [...globalsForSvelte4, ...globalsForSvelte5]
+  : globalsForSvelte4;

src/parser/index.ts

@@ -32,6 +32,7 @@ import {
   styleNodeLoc,
   styleNodeRange,
 } from "./style-context";
+import { globals } from "./globals";
 
 export {
   StyleContext,
@@ -122,7 +123,7 @@ export function parseForESLint(
   analyzeStoreScope(resultScript.scopeManager!); // for reactive vars
 
   // Add $$xxx variable
-  for (const $$name of ["$$slots", "$$props", "$$restProps"]) {
+  for (const $$name of globals) {
     const globalScope = resultScript.scopeManager!.globalScope;
     const variable = new Variable();
     variable.name = $$name;

src/parser/typescript/analyze/index.ts

@@ -16,12 +16,12 @@ import { VirtualTypeScriptContext } from "../context";
 import type { TSESParseForESLintResult } from "../types";
 import type ESTree from "estree";
 import type { SvelteAttribute, SvelteHTMLElement } from "../../../ast";
+import { globalsForSvelte5, globals } from "../../../parser/globals";
 
 export type AnalyzeTypeScriptContext = {
   slots: Set<SvelteHTMLElement>;
 };
 
-const RESERVED_NAMES = new Set<string>(["$$props", "$$restProps", "$$slots"]);
 /**
  * Analyze TypeScript source code.
  * Generate virtual code to provide correct type information for Svelte store reference namess and scopes.
@@ -75,8 +75,8 @@ function analyzeStoreReferenceNames(
     if (
       // Begin with `$`.
       reference.identifier.name.startsWith("$") &&
-      // Ignore it is a reserved variable.
-      !RESERVED_NAMES.has(reference.identifier.name) &&
+      // Ignore globals
+      !globals.includes(reference.identifier.name) &&
       // Ignore if it is already defined.
       !programScope.set.has(reference.identifier.name)
     ) {
@@ -215,6 +215,59 @@ function analyzeDollarDollarVariables(
     );
   }
 
+  addSvelte5Globals();
+
+  function addSvelte5Globals() {
+    for (const svelte5Global of globalsForSvelte5) {
+      if (
+        !scopeManager.globalScope!.through.some(
+          (reference) => reference.identifier.name === svelte5Global,
+        )
+      ) {
+        continue;
+      }
+      switch (svelte5Global) {
+        case "$state": {
+          appendDeclareFunctionVirtualScript(
+            svelte5Global,
+            "<T>(initial: T): T",
+          );
+          appendDeclareFunctionVirtualScript(
+            svelte5Global,
+            "<T>(): T | undefined",
+          );
+          break;
+        }
+        case "$derived": {
+          appendDeclareFunctionVirtualScript(
+            svelte5Global,
+            "<T>(expression: T): T",
+          );
+          break;
+        }
+        case "$effect": {
+          appendDeclareFunctionVirtualScript(
+            svelte5Global,
+            "(fn: () => void | (() => void)): void",
+          );
+          appendDeclareNamespaceVirtualScript(
+            svelte5Global,
+            "export function pre(fn: () => void | (() => void)): void;",
+          );
+          break;
+        }
+        case "$props": {
+          appendDeclareFunctionVirtualScript(svelte5Global, "<T>(): T");
+          break;
+        }
+        default: {
+          const _: never = svelte5Global;
+          throw Error(`Unknown global: ${_}`);
+        }
+      }
+    }
+  }
+
   /** Append declare virtual script */
   function appendDeclareVirtualScript(name: string, type: string) {
     ctx.appendVirtualScript(`declare let ${name}: ${type};`);
@@ -242,6 +295,59 @@ function analyzeDollarDollarVariables(
       return true;
     });
   }
+
+  /** Append declare virtual script */
+  function appendDeclareFunctionVirtualScript(name: string, type: string) {
+    ctx.appendVirtualScript(`declare function ${name}${type};`);
+    ctx.restoreContext.addRestoreStatementProcess((node, result) => {
+      if (
+        node.type !== "TSDeclareFunction" ||
+        !node.declare ||
+        node.id?.type !== "Identifier" ||
+        node.id.name !== name
+      ) {
+        return false;
+      }
+      const program = result.ast;
+      program.body.splice(program.body.indexOf(node), 1);
+
+      const scopeManager = result.scopeManager as ScopeManager;
+
+      // Remove `declare` variable
+      removeAllScopeAndVariableAndReference(node, {
+        visitorKeys: result.visitorKeys,
+        scopeManager,
+      });
+
+      return true;
+    });
+  }
+
+  function appendDeclareNamespaceVirtualScript(name: string, script: string) {
+    ctx.appendVirtualScript(`declare namespace $effect { ${script} }`);
+    ctx.restoreContext.addRestoreStatementProcess((node, result) => {
+      if (
+        node.type !== "TSModuleDeclaration" ||
+        !node.declare ||
+        node.id?.type !== "Identifier" ||
+        node.id.name !== name
+      ) {
+        return false;
+      }
+      const program = result.ast;
+      program.body.splice(program.body.indexOf(node), 1);
+
+      const scopeManager = result.scopeManager as ScopeManager;
+
+      // Remove `declare` variable
+      removeAllScopeAndVariableAndReference(node, {
+        visitorKeys: result.visitorKeys,
+        scopeManager,
+      });
+
+      return true;
+    });
+  }
 }
 
 /**

tests/fixtures/parser/ast/$$slots-scope-output-svelte5.json

@@ -0,0 +1,67 @@
+{
+  "variables": [
+    {
+      "name": "$$slots",
+      "identifiers": [],
+      "defs": [],
+      "references": [
+        {
+          "identifier": {
+            "type": "Identifier",
+            "name": "$$slots",
+            "range": [5, 12],
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 5
+              },
+              "end": {
+                "line": 1,
+                "column": 12
+              }
+            }
+          },
+          "from": "module",
+          "init": null,
+          "resolved": null
+        }
+      ]
+    },
+    {
+      "name": "$$props",
+      "identifiers": [],
+      "defs": [],
+      "references": []
+    },
+    {
+      "name": "$$restProps",
+      "identifiers": [],
+      "defs": [],
+      "references": []
+    },
+    {
+      "name": "$state",
+      "identifiers": [],
+      "defs": [],
+      "references": []
+    },
+    {
+      "name": "$derived",
+      "identifiers": [],
+      "defs": [],
+      "references": []
+    },
+    {
+      "name": "$effect",
+      "identifiers": [],
+      "defs": [],
+      "references": []
+    },
+    {
+      "name": "$props",
+      "identifiers": [],
+      "defs": [],
+      "references": []
+    }
+  ]
+}