feat: implement stores-no-async (#225)

* feat: implement stores-no-async rule

* test: add tests

* docs: add docs

* chore: add changeset

* fix: remove since

* fix: changeset

* fix: use ReferenceTracker

* fix: handled if fn is undefined

* fix: handle FunctionExpression also

.changeset/curvy-ants-admire.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-svelte": minor
+---
+
+Add svelte/stores-no-async rule

README.md

@@ -269,6 +269,7 @@ These rules relate to possible syntax or logic errors in Svelte code:
 | [svelte/no-not-function-handler](https://ota-meshi.github.io/eslint-plugin-svelte/rules/no-not-function-handler/) | disallow use of not function in event handler | :star: |
 | [svelte/no-object-in-text-mustaches](https://ota-meshi.github.io/eslint-plugin-svelte/rules/no-object-in-text-mustaches/) | disallow objects in text mustache interpolation | :star: |
 | [svelte/no-shorthand-style-property-overrides](https://ota-meshi.github.io/eslint-plugin-svelte/rules/no-shorthand-style-property-overrides/) | disallow shorthand style properties that override related longhand properties | :star: |
+| [svelte/no-store-async](https://ota-meshi.github.io/eslint-plugin-svelte/rules/no-store-async.md) | disallow using async/await inside svelte stores | :star: |
 | [svelte/no-unknown-style-directive-property](https://ota-meshi.github.io/eslint-plugin-svelte/rules/no-unknown-style-directive-property/) | disallow unknown `style:property` | :star: |
 | [svelte/valid-compile](https://ota-meshi.github.io/eslint-plugin-svelte/rules/valid-compile/) | disallow warnings when compiling. | :star: |
 

docs/rules.md

@@ -22,6 +22,7 @@ These rules relate to possible syntax or logic errors in Svelte code:
 | [svelte/no-not-function-handler](./rules/no-not-function-handler.md) | disallow use of not function in event handler | :star: |
 | [svelte/no-object-in-text-mustaches](./rules/no-object-in-text-mustaches.md) | disallow objects in text mustache interpolation | :star: |
 | [svelte/no-shorthand-style-property-overrides](./rules/no-shorthand-style-property-overrides.md) | disallow shorthand style properties that override related longhand properties | :star: |
+| [svelte/no-store-async](./rules/no-store-async.md) | disallow using async/await inside svelte stores | :star: |
 | [svelte/no-unknown-style-directive-property](./rules/no-unknown-style-directive-property.md) | disallow unknown `style:property` | :star: |
 | [svelte/valid-compile](./rules/valid-compile.md) | disallow warnings when compiling. | :star: |
 

docs/rules/no-store-async.md

@@ -0,0 +1,56 @@
+---
+pageClass: "rule-details"
+sidebarDepth: 0
+title: "svelte/no-store-async"
+description: "disallow using async/await inside svelte stores"
+---
+
+# svelte/no-store-async
+
+> disallow using async/await inside svelte stores
+
+- :gear: This rule is included in `"plugin:svelte/recommended"`.
+
+## :book: Rule Details
+
+This rule reports all uses of async/await inside svelte stores.
+Because it causes issues with the auto-unsubscribing features.
+
+<ESLintCodeBlock language="javascript">
+
+<!--eslint-skip-->
+
+```js
+/* eslint svelte/no-store-async: "error" */
+
+import { writable, readable, derived } from "svelte/store"
+
+/* ✓ GOOD */
+const w1 = writable(false, () => {})
+const r1 = readable(false, () => {})
+const d1 = derived(a1, ($a1) => {})
+
+/* ✗ BAD */
+const w2 = writable(false, async () => {})
+const r2 = readable(false, async () => {})
+const d2 = derived(a1, async ($a1) => {})
+```
+
+</ESLintCodeBlock>
+
+## :wrench: Options
+
+Nothing.
+
+## :books: Further Reading
+
+- [Svelte - Docs > 4. Prefix stores with $ to access their values / Store contract](https://svelte.dev/docs#component-format-script-4-prefix-stores-with-$-to-access-their-values-store-contract)
+
+## :rocket: Version
+
+This rule was introduced in eslint-plugin-svelte v3.1.0
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/ota-meshi/eslint-plugin-svelte/blob/main/src/rules/no-store-async.ts)
+- [Test source](https://github.com/ota-meshi/eslint-plugin-svelte/blob/main/tests/src/rules/no-store-async.ts)

src/rules/no-store-async.ts

@@ -0,0 +1,49 @@
+import { createRule } from "../utils"
+import { extractStoreReferences } from "./reference-helpers/svelte-store"
+
+export default createRule("no-store-async", {
+  meta: {
+    docs: {
+      description:
+        "disallow using async/await inside svelte stores because it causes issues with the auto-unsubscribing features",
+      category: "Possible Errors",
+      recommended: true,
+      default: "error",
+    },
+    schema: [],
+    messages: {
+      unexpected: "Do not pass async functions to svelte stores.",
+    },
+    type: "problem",
+  },
+  create(context) {
+    return {
+      Program() {
+        for (const { node } of extractStoreReferences(context)) {
+          const [, fn] = node.arguments
+          if (
+            !fn ||
+            (fn.type !== "ArrowFunctionExpression" &&
+              fn.type !== "FunctionExpression") ||
+            !fn.async
+          ) {
+            continue
+          }
+
+          const start = fn.loc?.start ?? { line: 1, column: 0 }
+          context.report({
+            node: fn,
+            loc: {
+              start,
+              end: {
+                line: start.line,
+                column: start.column + 5,
+              },
+            },
+            messageId: "unexpected",
+          })
+        }
+      },
+    }
+  },
+})

src/rules/reference-helpers/svelte-store.ts

@@ -0,0 +1,29 @@
+import type * as ESTree from "estree"
+import { ReferenceTracker } from "eslint-utils"
+import type { RuleContext } from "../../types"
+
+/** Extract 'svelte/store' references */
+export function* extractStoreReferences(
+  context: RuleContext,
+): Generator<{ node: ESTree.CallExpression; name: string }, void> {
+  const referenceTracker = new ReferenceTracker(context.getScope())
+  for (const { node, path } of referenceTracker.iterateEsmReferences({
+    "svelte/store": {
+      [ReferenceTracker.ESM]: true,
+      writable: {
+        [ReferenceTracker.CALL]: true,
+      },
+      readable: {
+        [ReferenceTracker.CALL]: true,
+      },
+      derived: {
+        [ReferenceTracker.CALL]: true,
+      },
+    },
+  })) {
+    yield {
+      node: node as ESTree.CallExpression,
+      name: path[path.length - 1],
+    }
+  }
+}

src/rules/require-stores-init.ts

@@ -1,6 +1,5 @@
 import { createRule } from "../utils"
-import type * as ESTree from "estree"
-import { ReferenceTracker } from "eslint-utils"
+import { extractStoreReferences } from "./reference-helpers/svelte-store"
 
 export default createRule("require-stores-init", {
   meta: {
@@ -16,33 +15,9 @@ export default createRule("require-stores-init", {
     type: "suggestion",
   },
   create(context) {
-    /** Extract 'svelte/store' references */
-    function* extractStoreReferences() {
-      const referenceTracker = new ReferenceTracker(context.getScope())
-      for (const { node, path } of referenceTracker.iterateEsmReferences({
-        "svelte/store": {
-          [ReferenceTracker.ESM]: true,
-          writable: {
-            [ReferenceTracker.CALL]: true,
-          },
-          readable: {
-            [ReferenceTracker.CALL]: true,
-          },
-          derived: {
-            [ReferenceTracker.CALL]: true,
-          },
-        },
-      })) {
-        yield {
-          node: node as ESTree.CallExpression,
-          name: path[path.length - 1],
-        }
-      }
-    }
-
     return {
       Program() {
-        for (const { node, name } of extractStoreReferences()) {
+        for (const { node, name } of extractStoreReferences(context)) {
           const minArgs =
             name === "writable" || name === "readable"
               ? 1

src/utils/rules.ts

@@ -21,6 +21,7 @@ import noReactiveFunctions from "../rules/no-reactive-functions"
 import noReactiveLiterals from "../rules/no-reactive-literals"
 import noShorthandStylePropertyOverrides from "../rules/no-shorthand-style-property-overrides"
 import noSpacesAroundEqualSignsInAttribute from "../rules/no-spaces-around-equal-signs-in-attribute"
+import noStoreAsync from "../rules/no-store-async"
 import noTargetBlank from "../rules/no-target-blank"
 import noUnknownStyleDirectiveProperty from "../rules/no-unknown-style-directive-property"
 import noUnusedSvelteIgnore from "../rules/no-unused-svelte-ignore"
@@ -59,6 +60,7 @@ export const rules = [
   noReactiveLiterals,
   noShorthandStylePropertyOverrides,
   noSpacesAroundEqualSignsInAttribute,
+  noStoreAsync,
   noTargetBlank,
   noUnknownStyleDirectiveProperty,
   noUnusedSvelteIgnore,

tests/fixtures/rules/no-store-async/invalid/test01-errors.yaml

@@ -0,0 +1,12 @@
+- message: Do not pass async functions to svelte stores.
+  line: 3
+  column: 28
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 6
+  column: 28
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 9
+  column: 24
+  suggestions: null

tests/fixtures/rules/no-store-async/invalid/test01-input.js

@@ -0,0 +1,11 @@
+import { writable, readable, derived } from "svelte/store"
+
+const w2 = writable(false, async () => {
+  /** do nothing */
+})
+const r2 = readable(false, async () => {
+  /** do nothing */
+})
+const d2 = derived(a1, async ($a1) => {
+  /** do nothing */
+})

tests/fixtures/rules/no-store-async/invalid/test02-errors.yaml

@@ -0,0 +1,12 @@
+- message: Do not pass async functions to svelte stores.
+  line: 3
+  column: 35
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 6
+  column: 35
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 9
+  column: 31
+  suggestions: null

tests/fixtures/rules/no-store-async/invalid/test02-input.js

@@ -0,0 +1,11 @@
+import * as stores from "svelte/store"
+
+const w2 = stores.writable(false, async () => {
+  /** do nothing */
+})
+const r2 = stores.readable(false, async () => {
+  /** do nothing */
+})
+const d2 = stores.derived(a1, async ($a1) => {
+  /** do nothing */
+})

tests/fixtures/rules/no-store-async/invalid/test03-errors.yaml

@@ -0,0 +1,12 @@
+- message: Do not pass async functions to svelte stores.
+  line: 3
+  column: 21
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 6
+  column: 21
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 9
+  column: 18
+  suggestions: null

tests/fixtures/rules/no-store-async/invalid/test03-input.js

@@ -0,0 +1,11 @@
+import { writable as A, readable as B, derived as C } from "svelte/store"
+
+const w2 = A(false, async () => {
+  /** do nothing */
+})
+const r2 = B(false, async () => {
+  /** do nothing */
+})
+const d2 = C(a1, async ($a1) => {
+  /** do nothing */
+})

tests/fixtures/rules/no-store-async/invalid/test04-errors.yaml

@@ -0,0 +1,12 @@
+- message: Do not pass async functions to svelte stores.
+  line: 3
+  column: 28
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 6
+  column: 28
+  suggestions: null
+- message: Do not pass async functions to svelte stores.
+  line: 9
+  column: 24
+  suggestions: null

tests/fixtures/rules/no-store-async/invalid/test04-input.js

@@ -0,0 +1,11 @@
+import { writable, readable, derived } from "svelte/store"
+
+const w2 = writable(false, async function () {
+  /** do nothing */
+})
+const r2 = readable(false, async function () {
+  /** do nothing */
+})
+const d2 = derived(a1, async function ($a1) {
+  /** do nothing */
+})

tests/fixtures/rules/no-store-async/valid/test01-input.js

@@ -0,0 +1,14 @@
+import { writable, readable, derived } from "svelte/store"
+
+const w1 = writable(false, () => {
+  /** do nothing */
+})
+const w2 = writable(false)
+const r1 = readable(false, () => {
+  /** do nothing */
+})
+const r2 = readable(false)
+const d1 = derived(a1, ($a1) => {
+  /** do nothing */
+})
+const d2 = derived(a1)

tests/src/rules/no-store-async.ts

@@ -0,0 +1,12 @@
+import { RuleTester } from "eslint"
+import rule from "../../../src/rules/no-store-async"
+import { loadTestCases } from "../../utils/utils"
+
+const tester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 2020,
+    sourceType: "module",
+  },
+})
+
+tester.run("no-store-async", rule as any, loadTestCases("no-store-async"))