fix: wrong store access type information (#204)

* fix: wrong store access type information

* Create grumpy-avocados-behave.md

* test: update new fixture

* test: ignore ts-eslint v4

Author: ota-meshi

.changeset/grumpy-avocados-behave.md

@@ -0,0 +1,5 @@
+---
+"svelte-eslint-parser": patch
+---
+
+fix: wrong store access type information

src/context/script-let.ts

@@ -116,6 +116,8 @@ export class ScriptLetContext {
 
   private readonly usedUniqueIds = new Set<string>();
 
+  private storeValueTypeName: string | undefined;
+
   public constructor(ctx: Context) {
     this.script = ctx.sourceCode.scripts;
     this.ctx = ctx;
@@ -537,8 +539,27 @@ export class ScriptLetContext {
     for (const nm of maybeStores) {
       if (reservedNames.has(nm)) continue;
 
+      if (!this.storeValueTypeName) {
+        this.storeValueTypeName = this.generateUniqueId("StoreValueType");
+
+        this.appendScriptWithoutOffset(
+          `type ${this.storeValueTypeName}<T> = T extends null | undefined
+  ? T
+  : T extends object & { subscribe(run: infer F, ...args: any): any }
+  ? F extends (value: infer V, ...args: any) => any
+    ? V
+    : never
+  : T;`,
+          (node, tokens, comments, result) => {
+            tokens.length = 0;
+            comments.length = 0;
+            removeAllScope(node, result);
+          }
+        );
+      }
+
       this.appendScriptWithoutOffset(
-        `declare let $${nm}: Parameters<Parameters<(typeof ${nm})["subscribe"]>[0]>[0];`,
+        `declare let $${nm}: ${this.storeValueTypeName}<typeof ${nm}>;`,
         (node, tokens, comments, result) => {
           tokens.length = 0;
           comments.length = 0;
@@ -933,9 +954,9 @@ function removeAllScope(target: ESTree.Node, result: ScriptLetCallbackOption) {
       }
       if (node.type === "Identifier") {
         let scope = result.getInnermostScope(node);
-        if (
-          (scope.block as any).type === "TSTypeAliasDeclaration" &&
-          (scope.block as any).id === node
+        while (
+          target.range![0] <= scope.block.range![0] &&
+          scope.block.range![1] <= target.range![1]
         ) {
           scope = scope.upper!;
         }

tests/fixtures/parser/ast/ts-store01-type-output.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { writable } from 'svelte/store'; // writable: <T>(value?: T, start?: StartStopNotifier<T>) => Writable<T>, writable: <T>(value?: T, start?: StartStopNotifier<T>) => Writable<T>
+	import { writable } from 'svelte/store'; // writable: <T>(value?: T | undefined, start?: StartStopNotifier<T> | undefined) => Writable<T>, writable: <T>(value?: T | undefined, start?: StartStopNotifier<T> | undefined) => Writable<T>
 	const a = writable(0) // a: Writable<number>, writable(0): Writable<number>
 	const b = writable(0) // b: Writable<number>, writable(0): Writable<number>
 	const $b = 'abc' // $b: "abc"
@@ -10,5 +10,5 @@
 {b} <!-- b: Writable<number> -->
 {$b} <!-- $b: "abc" -->
 {c} <!-- c: "abc" -->
-{$c} <!-- $c: never -->
-{$d} <!-- $d: never -->
+{$c} <!-- $c: "abc" -->
+{$d} <!-- $d: any -->

tests/fixtures/parser/ast/ts-store02-type-output.svelte

@@ -1,5 +1,5 @@
 <script context="module" lang="ts">
-	import { writable } from 'svelte/store'; // writable: <T>(value?: T, start?: StartStopNotifier<T>) => Writable<T>, writable: <T>(value?: T, start?: StartStopNotifier<T>) => Writable<T>
+	import { writable } from 'svelte/store'; // writable: <T>(value?: T | undefined, start?: StartStopNotifier<T> | undefined) => Writable<T>, writable: <T>(value?: T | undefined, start?: StartStopNotifier<T> | undefined) => Writable<T>
 	const a = writable(0) // a: Writable<number>, writable(0): Writable<number>
 	declare const $a: string // $a: string
 </script>

tests/fixtures/parser/ast/ts-store03-input.svelte

@@ -0,0 +1,15 @@
+<script lang="ts">
+	import { Writable, Readable } from 'svelte/store';
+	let maybeUndef: Writable<number> | undefined
+	let maybeNull: Readable<string> | null
+	let maybeNullAndStr: Readable<boolean> | null | string
+
+	export function fn() {
+		$maybeUndef;
+		$maybeNull;
+		$maybeNullAndStr;
+	}
+</script>
+{$maybeUndef}
+{$maybeNull}
+{$maybeNullAndStr}

tests/fixtures/parser/ast/ts-store03-no-unused-expressions-result.json

@@ -0,0 +1,20 @@
+[
+  {
+    "ruleId": "no-unused-expressions",
+    "code": "$maybeUndef;",
+    "line": 8,
+    "column": 3
+  },
+  {
+    "ruleId": "no-unused-expressions",
+    "code": "$maybeNull;",
+    "line": 9,
+    "column": 3
+  },
+  {
+    "ruleId": "no-unused-expressions",
+    "code": "$maybeNullAndStr;",
+    "line": 10,
+    "column": 3
+  }
+]