feat: Add `nonself` event modifier for non-interactive elements

.changeset/tough-kids-develop.md

@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: add `|nonself` event modifier for non-interactive elements with event listeners

documentation/docs/02-template-syntax/05-element-directives.md

@@ -59,6 +59,7 @@ The following modifiers are available:
 - `capture` — fires the handler during the _capture_ phase instead of the _bubbling_ phase
 - `once` — remove the handler after the first time it runs
 - `self` — only trigger handler if `event.target` is the element itself
+- `nonself` — only trigger handler when `event.target` is not the element itself, e.g. if the event bubbled from a child element
 - `trusted` — only trigger handler if `event.isTrusted` is `true`. I.e. if the event is triggered by a user action.
 
 Modifiers can be chained together, e.g. `on:click|once|capture={...}`.

documentation/tutorial/05-events/03-event-modifiers/text.md

@@ -23,6 +23,7 @@ The full list of modifiers:
 - `capture` — fires the handler during the _capture_ phase instead of the _bubbling_ phase ([MDN docs](https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Building_blocks/Events#Event_bubbling_and_capture))
 - `once` — remove the handler after the first time it runs
 - `self` — only trigger handler if event.target is the element itself
+- `nonself` —  only trigger handler when `event.target` is not the element itself, e.g. if the event bubbled from a child element
 - `trusted` — only trigger handler if `event.isTrusted` is `true`. I.e. if the event is triggered by a user action.
 
 You can chain modifiers together, e.g. `on:click|once|capture={...}`.

packages/svelte/src/compiler/compile/internal_exports.js

@@ -1,2 +1,2 @@
 // This file is automatically generated
-export default new Set(["HtmlTag","HtmlTagHydration","ResizeObserverSingleton","SvelteComponent","SvelteComponentDev","SvelteComponentTyped","SvelteElement","action_destroyer","add_attribute","add_classes","add_flush_callback","add_iframe_resize_listener","add_location","add_render_callback","add_styles","add_transform","afterUpdate","append","append_dev","append_empty_stylesheet","append_hydration","append_hydration_dev","append_styles","assign","attr","attr_dev","attribute_to_object","beforeUpdate","bind","binding_callbacks","blank_object","bubble","check_outros","children","claim_comment","claim_component","claim_element","claim_html_tag","claim_space","claim_svg_element","claim_text","clear_loops","comment","component_subscribe","compute_rest_props","compute_slots","construct_svelte_component","construct_svelte_component_dev","contenteditable_truthy_values","createEventDispatcher","create_animation","create_bidirectional_transition","create_component","create_custom_element","create_in_transition","create_out_transition","create_slot","create_ssr_component","current_component","custom_event","dataset_dev","debug","destroy_block","destroy_component","destroy_each","detach","detach_after_dev","detach_before_dev","detach_between_dev","detach_dev","dirty_components","dispatch_dev","each","element","element_is","empty","end_hydrating","ensure_array_like","ensure_array_like_dev","escape","escape_attribute_value","escape_object","exclude_internal_props","fix_and_destroy_block","fix_and_outro_and_destroy_block","fix_position","flush","flush_render_callbacks","getAllContexts","getContext","get_all_dirty_from_scope","get_binding_group_value","get_current_component","get_custom_elements_slots","get_root_for_style","get_slot_changes","get_spread_object","get_spread_update","get_store_value","get_svelte_dataset","globals","group_outros","handle_promise","hasContext","has_prop","head_selector","identity","init","init_binding_group","init_binding_group_dynamic","insert","insert_dev","insert_hydration","insert_hydration_dev","intros","invalid_attribute_name_character","is_client","is_crossorigin","is_empty","is_function","is_promise","is_void","listen","listen_dev","loop","loop_guard","merge_ssr_styles","missing_component","mount_component","noop","not_equal","now","null_to_empty","object_without_properties","onDestroy","onMount","once","outro_and_destroy_block","prevent_default","prop_dev","query_selector_all","raf","resize_observer_border_box","resize_observer_content_box","resize_observer_device_pixel_content_box","run","run_all","safe_not_equal","schedule_update","select_multiple_value","select_option","select_options","select_value","self","setContext","set_attributes","set_current_component","set_custom_element_data","set_custom_element_data_map","set_data","set_data_contenteditable","set_data_contenteditable_dev","set_data_dev","set_data_maybe_contenteditable","set_data_maybe_contenteditable_dev","set_dynamic_element_data","set_input_type","set_input_value","set_now","set_raf","set_store_value","set_style","set_svg_attributes","space","split_css_unit","spread","src_url_equal","srcset_url_equal","start_hydrating","stop_immediate_propagation","stop_propagation","subscribe","svg_element","text","tick","time_ranges_to_array","to_number","toggle_class","transition_in","transition_out","trusted","update_await_block_branch","update_keyed_each","update_slot","update_slot_base","validate_component","validate_dynamic_element","validate_each_keys","validate_slots","validate_store","validate_void_dynamic_element","xlink_attr"]);
+export default new Set(["HtmlTag","HtmlTagHydration","ResizeObserverSingleton","SvelteComponent","SvelteComponentDev","SvelteComponentTyped","SvelteElement","action_destroyer","add_attribute","add_classes","add_flush_callback","add_iframe_resize_listener","add_location","add_render_callback","add_styles","add_transform","afterUpdate","append","append_dev","append_empty_stylesheet","append_hydration","append_hydration_dev","append_styles","assign","attr","attr_dev","attribute_to_object","beforeUpdate","bind","binding_callbacks","blank_object","bubble","check_outros","children","claim_comment","claim_component","claim_element","claim_html_tag","claim_space","claim_svg_element","claim_text","clear_loops","comment","component_subscribe","compute_rest_props","compute_slots","construct_svelte_component","construct_svelte_component_dev","contenteditable_truthy_values","createEventDispatcher","create_animation","create_bidirectional_transition","create_component","create_custom_element","create_in_transition","create_out_transition","create_slot","create_ssr_component","current_component","custom_event","dataset_dev","debug","destroy_block","destroy_component","destroy_each","detach","detach_after_dev","detach_before_dev","detach_between_dev","detach_dev","dirty_components","dispatch_dev","each","element","element_is","empty","end_hydrating","ensure_array_like","ensure_array_like_dev","escape","escape_attribute_value","escape_object","exclude_internal_props","fix_and_destroy_block","fix_and_outro_and_destroy_block","fix_position","flush","flush_render_callbacks","getAllContexts","getContext","get_all_dirty_from_scope","get_binding_group_value","get_current_component","get_custom_elements_slots","get_root_for_style","get_slot_changes","get_spread_object","get_spread_update","get_store_value","get_svelte_dataset","globals","group_outros","handle_promise","hasContext","has_prop","head_selector","identity","init","init_binding_group","init_binding_group_dynamic","insert","insert_dev","insert_hydration","insert_hydration_dev","intros","invalid_attribute_name_character","is_client","is_crossorigin","is_empty","is_function","is_promise","is_void","listen","listen_dev","loop","loop_guard","merge_ssr_styles","missing_component","mount_component","nonself","noop","not_equal","now","null_to_empty","object_without_properties","onDestroy","onMount","once","outro_and_destroy_block","prevent_default","prop_dev","query_selector_all","raf","resize_observer_border_box","resize_observer_content_box","resize_observer_device_pixel_content_box","run","run_all","safe_not_equal","schedule_update","select_multiple_value","select_option","select_options","select_value","self","setContext","set_attributes","set_current_component","set_custom_element_data","set_custom_element_data_map","set_data","set_data_contenteditable","set_data_contenteditable_dev","set_data_dev","set_data_maybe_contenteditable","set_data_maybe_contenteditable_dev","set_dynamic_element_data","set_input_type","set_input_value","set_now","set_raf","set_store_value","set_style","set_svg_attributes","space","split_css_unit","spread","src_url_equal","srcset_url_equal","start_hydrating","stop_immediate_propagation","stop_propagation","subscribe","svg_element","text","tick","time_ranges_to_array","to_number","toggle_class","transition_in","transition_out","trusted","update_await_block_branch","update_keyed_each","update_slot","update_slot_base","validate_component","validate_dynamic_element","validate_each_keys","validate_slots","validate_store","validate_void_dynamic_element","xlink_attr"]);

packages/svelte/src/compiler/compile/nodes/Element.js

@@ -244,6 +244,7 @@ const valid_modifiers = new Set([
 	'passive',
 	'nonpassive',
 	'self',
+	'nonself',
 	'trusted'
 ]);
 const passive_events = new Set(['wheel', 'touchstart', 'touchmove', 'touchend', 'touchcancel']);
@@ -599,7 +600,9 @@ export default class Element extends Node {
 	}
 	validate_attributes_a11y() {
 		const { component, attributes, handlers } = this;
+		/** @type {Map<string, Attribute>} */
 		const attribute_map = new Map();
+		/** @type {Map<string, EventHandler>} */
 		const handlers_map = new Map();
 		attributes.forEach((attribute) => attribute_map.set(attribute.name, attribute));
 		handlers.forEach((handler) => handlers_map.set(handler.name, handler));
@@ -781,7 +784,7 @@ export default class Element extends Node {
 			}
 		});
 		// click-events-have-key-events
-		if (handlers_map.has('click')) {
+		if (handlers_map.get('click')?.modifiers.has('nonself') === false) {
 			const role = attribute_map.get('role');
 			const is_non_presentation_role =
 				role?.is_static &&
@@ -852,8 +855,10 @@ export default class Element extends Node {
 				is_non_interactive_roles(role_static_value)) ||
 				(is_non_interactive_element(this.name, attribute_map) && !role))
 		) {
-			const has_interactive_handlers = handlers.some((handler) =>
-				a11y_recommended_interactive_handlers.has(handler.name)
+			const has_interactive_handlers = handlers.some(
+				(handler) =>
+					a11y_recommended_interactive_handlers.has(handler.name) &&
+					!handler.modifiers.has('nonself')
 			);
 			if (has_interactive_handlers) {
 				component.warn(
@@ -874,13 +879,19 @@ export default class Element extends Node {
 			!is_non_interactive_roles(role_static_value) &&
 			!is_abstract_role(role_static_value)
 		) {
-			const interactive_handlers = handlers
-				.map((handler) => handler.name)
-				.filter((handlerName) => a11y_interactive_handlers.has(handlerName));
-			if (interactive_handlers.length > 0) {
+			const interactive_handler_names = handlers
+				.filter(
+					(handler) =>
+						a11y_interactive_handlers.has(handler.name) && !handler.modifiers.has('nonself')
+				)
+				.map((handler) => handler.name);
+			if (interactive_handler_names.length > 0) {
 				component.warn(
 					this,
-					compiler_warnings.a11y_no_static_element_interactions(this.name, interactive_handlers)
+					compiler_warnings.a11y_no_static_element_interactions(
+						this.name,
+						interactive_handler_names
+					)
 				);
 			}
 		}
@@ -1266,6 +1277,12 @@ export default class Element extends Node {
 					compiler_errors.invalid_event_modifier_combination('passive', 'nonpassive')
 				);
 			}
+			if (handler.modifiers.has('self') && handler.modifiers.has('nonself')) {
+				return component.error(
+					handler,
+					compiler_errors.invalid_event_modifier_combination('self', 'nonself')
+				);
+			}
 			handler.modifiers.forEach((modifier) => {
 				if (!valid_modifiers.has(modifier)) {
 					return component.error(

packages/svelte/src/compiler/compile/render_dom/wrappers/Element/EventHandler.js

@@ -50,6 +50,7 @@ export default class EventHandlerWrapper {
 		if (this.node.modifiers.has('stopImmediatePropagation'))
 			snippet = x`@stop_immediate_propagation(${snippet})`;
 		if (this.node.modifiers.has('self')) snippet = x`@self(${snippet})`;
+		if (this.node.modifiers.has('nonself')) snippet = x`@nonself(${snippet})`;
 		if (this.node.modifiers.has('trusted')) snippet = x`@trusted(${snippet})`;
 		const args = [];
 		const opts = ['nonpassive', 'passive', 'once', 'capture'].filter((mod) =>

packages/svelte/src/runtime/internal/dom.js

@@ -399,6 +399,15 @@ export function self(fn) {
 	};
 }
 
+/**
+ * @returns {(event: any) => void} */
+export function nonself(fn) {
+	return function (event) {
+		// @ts-ignore
+		if (event.target !== event.currentTarget) fn.call(this, event);
+	};
+}
+
 /**
  * @returns {(event: any) => void} */
 export function trusted(fn) {

packages/svelte/test/runtime/samples/event-handler-dynamic-modifier-nonself/_config.js

@@ -0,0 +1,18 @@
+export default {
+	html: `
+		<div>
+			<button>click me</button>
+		</div>
+	`,
+
+	async test({ assert, component, target, window }) {
+		const button = target.querySelector('button');
+		const event = new window.MouseEvent('click', { bubbles: true });
+
+		await button.parentNode.dispatchEvent(event);
+		assert.ok(!component.clicked);
+
+		await button.dispatchEvent(event);
+		assert.ok(component.clicked);
+	}
+};

packages/svelte/test/runtime/samples/event-handler-dynamic-modifier-nonself/main.svelte

@@ -0,0 +1,13 @@
+<script>
+	export let clicked;
+	let f;
+
+	function handle_click(event) {
+		clicked = true;
+	}
+	f = handle_click;
+</script>
+
+<div on:click|nonself={f}>
+	<button>click me</button>
+</div>

packages/svelte/test/runtime/samples/event-handler-modifier-nonself/_config.js

@@ -0,0 +1,18 @@
+export default {
+	html: `
+		<div>
+			<button>click me</button>
+		</div>
+	`,
+
+	async test({ assert, component, target, window }) {
+		const button = target.querySelector('button');
+		const event = new window.MouseEvent('click', { bubbles: true });
+
+		await button.parentNode.dispatchEvent(event);
+		assert.ok(!component.clicked);
+
+		await button.dispatchEvent(event);
+		assert.ok(component.clicked);
+	}
+};

packages/svelte/test/runtime/samples/event-handler-modifier-nonself/main.svelte

@@ -0,0 +1,11 @@
+<script>
+	export let clicked;
+
+	function handle_click(event) {
+		clicked = true;
+	}
+</script>
+
+<div on:click|nonself={handle_click}>
+	<button>click me</button>
+</div>

packages/svelte/test/runtime/samples/event-handler-modifier-self/_config.js

@@ -7,10 +7,12 @@ export default {
 
 	async test({ assert, component, target, window }) {
 		const button = target.querySelector('button');
-		const event = new window.MouseEvent('click');
+		const event = new window.MouseEvent('click', { bubbles: true });
 
 		await button.dispatchEvent(event);
-
 		assert.ok(!component.inner_clicked);
+
+		await button.parentNode.dispatchEvent(event);
+		assert.ok(component.inner_clicked);
 	}
 };

packages/svelte/test/validator/samples/a11y-no-noninteractive-element-interactions/input.svelte

@@ -5,6 +5,7 @@
 <button on:click={() => {}} />
 <h1 contenteditable="true" on:keydown={() => {}}>Heading</h1>
 <h1>Heading</h1>
+<div role="paragraph" on:mouseup|nonself={() => {}}><slot name="interactive-element-goes-here"></slot></div>
 
 <!-- INVALID -->
 <div role="listitem" on:mousedown={() => {}} />

packages/svelte/test/validator/samples/a11y-no-noninteractive-element-interactions/warnings.json

@@ -3,60 +3,60 @@
 		"code": "a11y-no-noninteractive-element-interactions",
 		"end": {
 			"column": 47,
-			"line": 10
+			"line": 11
 		},
 		"message": "A11y: Non-interactive element <div> should not be assigned mouse or keyboard event listeners.",
 		"start": {
 			"column": 0,
-			"line": 10
+			"line": 11
 		}
 	},
 	{
 		"code": "a11y-no-noninteractive-element-interactions",
 		"end": {
 			"column": 58,
-			"line": 11
+			"line": 12
 		},
 		"message": "A11y: Non-interactive element <h1> should not be assigned mouse or keyboard event listeners.",
 		"start": {
 			"column": 0,
-			"line": 11
+			"line": 12
 		}
 	},
 	{
 		"code": "a11y-no-noninteractive-element-interactions",
 		"end": {
 			"column": 50,
-			"line": 12
+			"line": 13
 		},
 		"message": "A11y: Non-interactive element <h1> should not be assigned mouse or keyboard event listeners.",
 		"start": {
 			"column": 0,
-			"line": 12
+			"line": 13
 		}
 	},
 	{
 		"code": "a11y-no-noninteractive-element-interactions",
 		"end": {
 			"column": 28,
-			"line": 13
+			"line": 14
 		},
 		"message": "A11y: Non-interactive element <p> should not be assigned mouse or keyboard event listeners.",
 		"start": {
 			"column": 0,
-			"line": 13
+			"line": 14
 		}
 	},
 	{
 		"code": "a11y-no-noninteractive-element-interactions",
 		"end": {
 			"column": 46,
-			"line": 14
+			"line": 15
 		},
 		"message": "A11y: Non-interactive element <div> should not be assigned mouse or keyboard event listeners.",
 		"start": {
 			"column": 0,
-			"line": 14
+			"line": 15
 		}
 	}
 ]

packages/svelte/test/validator/samples/a11y-no-noninteractive-tabindex/input.svelte

@@ -14,3 +14,4 @@
 <div role='article' tabindex='0' />
 <article tabindex='0' />
 <article tabindex='{0}' />
+<div tabindex='0' on:click|nonself={() => {}}><slot name="interactive-element-goes-here"></slot></div>

packages/svelte/test/validator/samples/a11y-no-noninteractive-tabindex/warnings.json

@@ -46,5 +46,17 @@
 			"column": 0,
 			"line": 16
 		}
+	},
+	{
+		"code": "a11y-no-noninteractive-tabindex",
+		"end": {
+			"column": 102,
+			"line": 17
+		},
+		"message": "A11y: noninteractive element cannot have nonnegative tabIndex value",
+		"start": {
+			"column": 0,
+			"line": 17
+		}
 	}
 ]

packages/svelte/test/validator/samples/a11y-no-static-element-interactions/input.svelte

@@ -12,6 +12,7 @@
 <div role={dynamicRole} on:click={() => {}} />
 <!-- svelte-ignore a11y-no-noninteractive-element-interactions -->
 <footer on:keydown={() => {}} />
+<div on:click|nonself={() => {}}><slot name="interactive-element-goes-here"></slot></div>
 
 <!-- invalid -->
 <div on:keydown={() => {}} />

packages/svelte/test/validator/samples/a11y-no-static-element-interactions/warnings.json

@@ -3,24 +3,24 @@
 		"code": "a11y-no-static-element-interactions",
 		"end": {
 			"column": 29,
-			"line": 17
+			"line": 18
 		},
 		"message": "A11y: <div> with keydown handler must have an ARIA role",
 		"start": {
 			"column": 0,
-			"line": 17
+			"line": 18
 		}
 	},
 	{
 		"code": "a11y-no-static-element-interactions",
 		"end": {
 			"column": 76,
-			"line": 19
+			"line": 20
 		},
 		"message": "A11y: <a> with mousedown, mouseup handlers must have an ARIA role",
 		"start": {
 			"column": 0,
-			"line": 19
+			"line": 20
 		}
 	}
 ]

packages/svelte/test/validator/samples/event-modifiers-invalid-nonself/errors.json

@@ -0,0 +1,14 @@
+[
+	{
+		"message": "The 'self' and 'nonself' modifiers cannot be used together",
+		"code": "invalid-event-modifier",
+		"start": {
+			"line": 1,
+			"column": 5
+		},
+		"end": {
+			"line": 1,
+			"column": 45
+		}
+	}
+]

packages/svelte/test/validator/samples/event-modifiers-invalid-nonself/input.svelte

@@ -0,0 +1,3 @@
+<div on:touchstart|nonself|self={handleWheel}>
+	oops
+</div>

packages/svelte/test/validator/samples/event-modifiers-invalid/errors.json

@@ -1,6 +1,6 @@
 [
 	{
-		"message": "Valid event modifiers are preventDefault, stopPropagation, stopImmediatePropagation, capture, once, passive, nonpassive, self or trusted",
+		"message": "Valid event modifiers are preventDefault, stopPropagation, stopImmediatePropagation, capture, once, passive, nonpassive, self, nonself or trusted",
 		"code": "invalid-event-modifier",
 		"start": {
 			"line": 1,