sveltejs · ota-meshi · May 13, 2025 · Apr 17, 2025 · Apr 21, 2025 · Apr 24, 2025
diff --git a/.changeset/sad-points-strive.md b/.changeset/sad-points-strive.md
@@ -0,0 +1,5 @@
+---
+'eslint-plugin-svelte': minor
+---
+
+Added `no-add-event-listener` rule to disallow usages of `addEventListener`
diff --git a/README.md b/README.md
@@ -294,6 +294,7 @@ These rules relate to better ways of doing things to help you avoid problems:
 |:--------|:------------|:---|
 | [svelte/block-lang](https://sveltejs.github.io/eslint-plugin-svelte/rules/block-lang/) | disallows the use of languages other than those specified in the configuration for the lang attribute of `<script>` and `<style>` blocks. | :bulb: |
 | [svelte/button-has-type](https://sveltejs.github.io/eslint-plugin-svelte/rules/button-has-type/) | disallow usage of button without an explicit type attribute |  |
+| [svelte/no-add-event-listener](https://sveltejs.github.io/eslint-plugin-svelte/rules/no-add-event-listener/) | Warns against the use of `addEventListener` | :bulb: |
 | [svelte/no-at-debug-tags](https://sveltejs.github.io/eslint-plugin-svelte/rules/no-at-debug-tags/) | disallow the use of `{@debug}` | :star::bulb: |
 | [svelte/no-ignored-unsubscribe](https://sveltejs.github.io/eslint-plugin-svelte/rules/no-ignored-unsubscribe/) | disallow ignoring the unsubscribe method returned by the `subscribe()` on Svelte stores. |  |
 | [svelte/no-immutable-reactive-statements](https://sveltejs.github.io/eslint-plugin-svelte/rules/no-immutable-reactive-statements/) | disallow reactive statements that don't reference reactive values. | :star: |

diff --git a/docs/rules.md b/docs/rules.md
@@ -51,6 +51,7 @@ These rules relate to better ways of doing things to help you avoid problems:
 | :--------------------------------------------------------------------------------------- | :---------------------------------------------------------------------------------------------------------------------------------------- | :------------- |
 | [svelte/block-lang](./rules/block-lang.md)                                               | disallows the use of languages other than those specified in the configuration for the lang attribute of `<script>` and `<style>` blocks. | :bulb:         |
 | [svelte/button-has-type](./rules/button-has-type.md)                                     | disallow usage of button without an explicit type attribute                                                                               |                |
+| [svelte/no-add-event-listener](./rules/no-add-event-listener.md)                         | Warns against the use of `addEventListener`                                                                                               | :bulb:         |
 | [svelte/no-at-debug-tags](./rules/no-at-debug-tags.md)                                   | disallow the use of `{@debug}`                                                                                                            | :star::bulb:   |
 | [svelte/no-ignored-unsubscribe](./rules/no-ignored-unsubscribe.md)                       | disallow ignoring the unsubscribe method returned by the `subscribe()` on Svelte stores.                                                  |                |
 | [svelte/no-immutable-reactive-statements](./rules/no-immutable-reactive-statements.md)   | disallow reactive statements that don't reference reactive values.                                                                        | :star:         |

diff --git a/docs/rules/no-add-event-listener.md b/docs/rules/no-add-event-listener.md
@@ -0,0 +1,50 @@
+---
+pageClass: 'rule-details'
+sidebarDepth: 0
+title: 'svelte/no-add-event-listener'
+description: 'Warns against the use of `addEventListener`'
+---
+
+# svelte/no-add-event-listener
+
+> Warns against the use of `addEventListener`
+
+- :exclamation: <badge text="This rule has not been released yet." vertical="middle" type="error"> **_This rule has not been released yet._** </badge>
+- :bulb: Some problems reported by this rule are manually fixable by editor [suggestions](https://eslint.org/docs/developer-guide/working-with-rules#providing-suggestions).
+
+## :book: Rule Details
+
+Svelte relies on event delegation for performance and predictable handler order. Calling `addEventListener` inside a component skips this mechanism. This rule reports any call to `addEventListener` suggests converting to the `on()` helper from `svelte/events`.
+
+<!--eslint-skip-->
+
+```svelte
+<!-- ✓ GOOD -->
+<script>
+  /* eslint svelte/no-add-event-listener: "error" */
+  on(window, 'resize', handler);
+</script>
+```
+
+<!--eslint-skip-->
+
+```svelte
+<!-- ✗ BAD -->
+<script>
+  /* eslint svelte/no-add-event-listener: "error" */
+  window.addEventListener('resize', handler);
+</script>
+```
+
+## :books: Further reading
+
+- [svelte - event delegation]
+- [svelte/events `on` documentation]
+
+[svelte - event delegation]: https://svelte.dev/docs/svelte/basic-markup#Events-Event-delegation
+[svelte/events `on` documentation]: https://svelte.dev/docs/svelte/svelte-events#on
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/sveltejs/eslint-plugin-svelte/blob/main/packages/eslint-plugin-svelte/src/rules/no-add-event-listener.ts)
+- [Test source](https://github.com/sveltejs/eslint-plugin-svelte/blob/main/packages/eslint-plugin-svelte/tests/src/rules/no-add-event-listener.ts)
diff --git a/packages/eslint-plugin-svelte/src/rule-types.ts b/packages/eslint-plugin-svelte/src/rule-types.ts
@@ -99,6 +99,11 @@ export interface RuleOptions {
    * @see https://sveltejs.github.io/eslint-plugin-svelte/rules/mustache-spacing/
    */
   'svelte/mustache-spacing'?: Linter.RuleEntry<SvelteMustacheSpacing>
+  /**
+   * Warns against the use of `addEventListener`
+   * @see https://sveltejs.github.io/eslint-plugin-svelte/rules/no-add-event-listener/
+   */
+  'svelte/no-add-event-listener'?: Linter.RuleEntry<[]>
   /**
    * disallow the use of `{@debug}`
    * @see https://sveltejs.github.io/eslint-plugin-svelte/rules/no-at-debug-tags/

diff --git a/packages/eslint-plugin-svelte/src/rules/no-add-event-listener.ts b/packages/eslint-plugin-svelte/src/rules/no-add-event-listener.ts
@@ -0,0 +1,69 @@
+import type { TSESTree } from '@typescript-eslint/types';
+
+import { createRule } from '../utils/index.js';
+import type { SuggestionReportDescriptor } from '../types.js';
+
+export default createRule('no-add-event-listener', {
+	meta: {
+		docs: {
+			description: 'Warns against the use of `addEventListener`',
+			category: 'Best Practices',
+			recommended: false
+		},
+		hasSuggestions: true,
+		schema: [],
+		messages: {
+			unexpected:
+				'Do not use `addEventListener`. Use the `on` function from `svelte/events` instead.'
+		},
+		type: 'suggestion',
+		conditions: [
+			{
+				svelteVersions: ['5']
+			}
+		]
+	},
+	create(context) {
+		return {
+			CallExpression(node: TSESTree.CallExpression) {
+				const { callee } = node;
+				let target: string | null = null;
+
+				if (
+					callee.type === 'MemberExpression' &&
+					callee.property.type === 'Identifier' &&
+					callee.property.name === 'addEventListener'
+				) {
+					target = context.sourceCode.getText(callee.object);
+				} else if (callee.type === 'Identifier' && callee.name === 'addEventListener') {
+					target = 'window';
+				}
+
+				if (target === null) {
+					return;
+				}
+
+				const openParen = context.sourceCode.getTokenAfter(callee);
+				const suggest: SuggestionReportDescriptor[] = [];
+
+				if (openParen !== null) {
+					suggest.push({
+						desc: 'Use `on` from `svelte/events` instead',
+						fix(fixer) {
+							return [
+								fixer.replaceText(callee, 'on'),
+								fixer.insertTextAfter(openParen, `${target}, `)
+							];
+						}
+					});
+				}
+
+				context.report({
+					node,
+					messageId: 'unexpected',
+					suggest
+				});
+			}
+		};
+	}
+});
diff --git a/packages/eslint-plugin-svelte/src/utils/rules.ts b/packages/eslint-plugin-svelte/src/utils/rules.ts
@@ -19,6 +19,7 @@ import indent from '../rules/indent.js';
 import infiniteReactiveLoop from '../rules/infinite-reactive-loop.js';
 import maxAttributesPerLine from '../rules/max-attributes-per-line.js';
 import mustacheSpacing from '../rules/mustache-spacing.js';
+import noAddEventListener from '../rules/no-add-event-listener.js';
 import noAtDebugTags from '../rules/no-at-debug-tags.js';
 import noAtHtmlTags from '../rules/no-at-html-tags.js';
 import noDomManipulating from '../rules/no-dom-manipulating.js';
@@ -96,6 +97,7 @@ export const rules = [
 	infiniteReactiveLoop,
 	maxAttributesPerLine,
 	mustacheSpacing,
+	noAddEventListener,
 	noAtDebugTags,
 	noAtHtmlTags,
 	noDomManipulating,

diff --git a/...slint-plugin-svelte/tests/fixtures/rules/no-add-event-listener/invalid/_requirements.json b/...slint-plugin-svelte/tests/fixtures/rules/no-add-event-listener/invalid/_requirements.json
@@ -0,0 +1,3 @@
+{
+	"svelte": ">=5.0.0-0"
+}