fix: resolve to module scope for top level statements (#292)

* fix: resolve to module scope for top level statements

* Create .changeset/modern-spiders-retire.md

Author: ota-meshi

.changeset/modern-spiders-retire.md

@@ -0,0 +1,7 @@
+---
+"svelte-eslint-parser": minor
+---
+
+BREAKING: fix resolve to module scope for top level statements
+
+This change corrects the result of `context.getScope()`, but it is a breaking change.

src/context/script-let.ts

@@ -58,6 +58,7 @@ type ScriptLetRestoreCallbackOption = {
   registerNodeToScope: (node: any, scope: Scope) => void;
   scopeManager: ScopeManager;
   visitorKeys?: { [type: string]: string[] };
+  addPostProcess: (callback: () => void) => void;
 };
 
 /**
@@ -130,6 +131,8 @@ export class ScriptLetContext {
 
   private readonly restoreCallbacks: RestoreCallback[] = [];
 
+  private readonly programRestoreCallbacks: ScriptLetRestoreCallback[] = [];
+
   private readonly closeScopeCallbacks: (() => void)[] = [];
 
   private readonly unique = new UniqueIdGenerator();
@@ -574,6 +577,10 @@ export class ScriptLetContext {
     this.closeScopeCallbacks.pop()!();
   }
 
+  public addProgramRestore(callback: ScriptLetRestoreCallback): void {
+    this.programRestoreCallbacks.push(callback);
+  }
+
   private appendScript(
     text: string,
     offset: number,
@@ -631,6 +638,57 @@ export class ScriptLetContext {
    * Restore AST nodes
    */
   public restore(result: ESLintExtendedProgram): void {
+    const nodeToScope = getNodeToScope(result.scopeManager!);
+    const postprocessList: (() => void)[] = [];
+
+    const callbackOption: ScriptLetRestoreCallbackOption = {
+      getScope,
+      getInnermostScope,
+      registerNodeToScope,
+      scopeManager: result.scopeManager!,
+      visitorKeys: result.visitorKeys,
+      addPostProcess: (cb) => postprocessList.push(cb),
+    };
+
+    this.restoreNodes(result, callbackOption);
+    this.restoreProgram(result, callbackOption);
+    postprocessList.forEach((p) => p());
+
+    // Helpers
+    /** Get scope */
+    function getScope(node: ESTree.Node) {
+      return getScopeFromNode(result.scopeManager!, node);
+    }
+
+    /** Get innermost scope */
+    function getInnermostScope(node: ESTree.Node) {
+      return getInnermostScopeFromNode(result.scopeManager!, node);
+    }
+
+    /** Register node to scope */
+    function registerNodeToScope(node: any, scope: Scope): void {
+      // If we replace the `scope.block` at this time,
+      // the scope restore calculation will not work, so we will replace the `scope.block` later.
+      postprocessList.push(() => {
+        scope.block = node;
+      });
+
+      const scopes = nodeToScope.get(node);
+      if (scopes) {
+        scopes.push(scope);
+      } else {
+        nodeToScope.set(node, [scope]);
+      }
+    }
+  }
+
+  /**
+   * Restore AST nodes
+   */
+  private restoreNodes(
+    result: ESLintExtendedProgram,
+    callbackOption: ScriptLetRestoreCallbackOption
+  ): void {
     let orderedRestoreCallback = this.restoreCallbacks.shift();
     if (!orderedRestoreCallback) {
       return;
@@ -640,8 +698,6 @@ export class ScriptLetContext {
     const processedTokens = [];
     const comments = result.ast.comments;
     const processedComments = [];
-    const nodeToScope = getNodeToScope(result.scopeManager!);
-    const postprocessList: (() => void)[] = [];
 
     let tok;
     while ((tok = tokens.shift())) {
@@ -731,13 +787,12 @@ export class ScriptLetContext {
           startIndex.comment,
           endIndex.comment - startIndex.comment
         );
-        restoreCallback.callback(node, targetTokens, targetComments, {
-          getScope,
-          getInnermostScope,
-          registerNodeToScope,
-          scopeManager: result.scopeManager!,
-          visitorKeys: result.visitorKeys,
-        });
+        restoreCallback.callback(
+          node,
+          targetTokens,
+          targetComments,
+          callbackOption
+        );
 
         processedTokens.push(...targetTokens);
         processedComments.push(...targetComments);
@@ -750,33 +805,22 @@ export class ScriptLetContext {
 
     result.ast.tokens = processedTokens;
     result.ast.comments = processedComments;
-    postprocessList.forEach((p) => p());
-
-    // Helpers
-    /** Get scope */
-    function getScope(node: ESTree.Node) {
-      return getScopeFromNode(result.scopeManager!, node);
-    }
-
-    /** Get innermost scope */
-    function getInnermostScope(node: ESTree.Node) {
-      return getInnermostScopeFromNode(result.scopeManager!, node);
-    }
-
-    /** Register node to scope */
-    function registerNodeToScope(node: any, scope: Scope): void {
-      // If we replace the `scope.block` at this time,
-      // the scope restore calculation will not work, so we will replace the `scope.block` later.
-      postprocessList.push(() => {
-        scope.block = node;
-      });
+  }
 
-      const scopes = nodeToScope.get(node);
-      if (scopes) {
-        scopes.push(scope);
-      } else {
-        nodeToScope.set(node, [scope]);
-      }
+  /**
+   * Restore program node
+   */
+  private restoreProgram(
+    result: ESLintExtendedProgram,
+    callbackOption: ScriptLetRestoreCallbackOption
+  ): void {
+    for (const callback of this.programRestoreCallbacks) {
+      callback(
+        result.ast,
+        result.ast.tokens,
+        result.ast.comments,
+        callbackOption
+      );
     }
   }
 

src/parser/converts/root.ts

@@ -9,6 +9,7 @@ import {} from "./common";
 import type { Context } from "../../context";
 import { convertChildren, extractElementTags } from "./element";
 import { convertAttributeTokens } from "./attr";
+import type { Scope } from "eslint-scope";
 
 /**
  * Convert root
@@ -127,6 +128,30 @@ export function convertSvelteRoot(
     body.push(style);
   }
 
+  // Set the scope of the Program node.
+  ctx.scriptLet.addProgramRestore(
+    (
+      node,
+      _tokens,
+      _comments,
+      { scopeManager, registerNodeToScope, addPostProcess }
+    ) => {
+      const scopes: Scope[] = [];
+      for (const scope of scopeManager.scopes) {
+        if (scope.block === node) {
+          registerNodeToScope(ast, scope);
+          scopes.push(scope);
+        }
+      }
+      addPostProcess(() => {
+        // Reverts the node indicated by `block` to the original Program node.
+        // This state is incorrect, but `eslint-utils`'s `referenceTracker.iterateEsmReferences()` tracks import statements
+        // from Program nodes set to `block` in global scope. This can only be handled by the original Program node.
+        scopeManager.globalScope.block = node;
+      });
+    }
+  );
+
   return ast;
 }
 

tests/src/scope/scope.ts

@@ -0,0 +1,77 @@
+import { Linter } from "eslint";
+import assert from "assert";
+import * as parser from "../../../src/index";
+import type { Scope } from "eslint-scope";
+
+function generateScopeTestCase(code: string, selector: string, type: string) {
+  const linter = new Linter();
+  let scope: Scope;
+  linter.defineParser("svelte-eslint-parser", parser as any);
+  linter.defineRule("test", {
+    create(context) {
+      return {
+        [selector]() {
+          scope = context.getScope();
+        },
+      };
+    },
+  });
+  linter.verify(code, {
+    parser: "svelte-eslint-parser",
+    parserOptions: { ecmaVersion: 2020, sourceType: "module" },
+    rules: {
+      test: "error",
+    },
+  });
+  assert.strictEqual(scope!.type, type);
+}
+
+describe("context.getScope", () => {
+  it("returns the global scope for the root node", () => {
+    generateScopeTestCase("", "Program", "global");
+  });
+
+  it("returns the global scope for the script element", () => {
+    generateScopeTestCase("<script></script>", "SvelteScriptElement", "module");
+  });
+
+  it("returns the module scope for nodes for top level nodes of script", () => {
+    generateScopeTestCase(
+      '<script>import mod from "mod";</script>',
+      "ImportDeclaration",
+      "module"
+    );
+  });
+
+  it("returns the module scope for nested nodes without their own scope", () => {
+    generateScopeTestCase(
+      "<script>a || b</script>",
+      "LogicalExpression",
+      "module"
+    );
+  });
+
+  it("returns the the child scope of top level nodes with their own scope", () => {
+    generateScopeTestCase(
+      "<script>function fn() {}</script>",
+      "FunctionDeclaration",
+      "function"
+    );
+  });
+
+  it("returns the own scope for nested nodes", () => {
+    generateScopeTestCase(
+      "<script>a || (() => {})</script>",
+      "ArrowFunctionExpression",
+      "function"
+    );
+  });
+
+  it("returns the the nearest child scope for statements inside non-global scopes", () => {
+    generateScopeTestCase(
+      "<script>function fn() { nested; }</script>",
+      "ExpressionStatement",
+      "function"
+    );
+  });
+});