breaking: remove foreign namespace

.changeset/gorgeous-coats-jog.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+breaking: remove foreign namespace

packages/svelte/src/compiler/phases/1-parse/read/options.js

@@ -157,18 +157,10 @@ export default function read_options(node) {
 					component_options.namespace = 'svg';
 				} else if (value === NAMESPACE_MATHML) {
 					component_options.namespace = 'mathml';
-				} else if (
-					value === 'html' ||
-					value === 'mathml' ||
-					value === 'svg' ||
-					value === 'foreign'
-				) {
+				} else if (value === 'html' || value === 'mathml' || value === 'svg') {
 					component_options.namespace = value;
 				} else {
-					e.svelte_options_invalid_attribute_value(
-						attribute,
-						`"html", "mathml", "svg" or "foreign"`
-					);
+					e.svelte_options_invalid_attribute_value(attribute, `"html", "mathml" or "svg"`);
 				}
 
 				break;

packages/svelte/src/compiler/phases/2-analyze/visitors/BindDirective.js

@@ -126,10 +126,6 @@ export function BindDirective(node, context) {
 		parent?.type === 'SvelteDocument' ||
 		parent?.type === 'SvelteBody'
 	) {
-		if (context.state.options.namespace === 'foreign' && node.name !== 'this') {
-			e.bind_invalid_name(node, node.name, 'Foreign elements only support `bind:this`');
-		}
-
 		if (node.name in binding_properties) {
 			const property = binding_properties[node.name];
 			if (property.valid_elements && !property.valid_elements.includes(parent.name)) {

packages/svelte/src/compiler/phases/2-analyze/visitors/RegularElement.js

@@ -24,11 +24,7 @@ export function RegularElement(node, context) {
 	context.state.analysis.elements.push(node);
 
 	// Special case: Move the children of <textarea> into a value attribute if they are dynamic
-	if (
-		context.state.options.namespace !== 'foreign' &&
-		node.name === 'textarea' &&
-		node.fragment.nodes.length > 0
-	) {
+	if (node.name === 'textarea' && node.fragment.nodes.length > 0) {
 		for (const attribute of node.attributes) {
 			if (attribute.type === 'Attribute' && attribute.name === 'value') {
 				e.textarea_invalid_content(node);
@@ -65,7 +61,6 @@ export function RegularElement(node, context) {
 	// Special case: single expression tag child of option element -> add "fake" attribute
 	// to ensure that value types are the same (else for example numbers would be strings)
 	if (
-		context.state.options.namespace !== 'foreign' &&
 		node.name === 'option' &&
 		node.fragment.nodes?.length === 1 &&
 		node.fragment.nodes[0].type === 'ExpressionTag' &&
@@ -90,10 +85,8 @@ export function RegularElement(node, context) {
 		(attribute) => attribute.type === 'SpreadAttribute'
 	);
 
-	if (context.state.options.namespace !== 'foreign') {
-		node.metadata.svg = is_svg(node.name);
-		node.metadata.mathml = is_mathml(node.name);
-	}
+	node.metadata.svg = is_svg(node.name);
+	node.metadata.mathml = is_mathml(node.name);
 
 	if (context.state.parent_element) {
 		let past_parent = false;
@@ -156,7 +149,6 @@ export function RegularElement(node, context) {
 
 	if (
 		context.state.analysis.source[node.end - 2] === '/' &&
-		context.state.options.namespace !== 'foreign' &&
 		!is_void(node_name) &&
 		!is_svg(node_name)
 	) {

packages/svelte/src/compiler/phases/2-analyze/visitors/shared/a11y.js

@@ -687,9 +687,6 @@ function get_static_text_value(attribute) {
  * @param {AnalysisState} state
  */
 export function check_element(node, state) {
-	// foreign namespace means elements can have completely different meanings, therefore we don't check them
-	if (state.options.namespace === 'foreign') return;
-
 	/** @type {Map<string, Attribute>} */
 	const attribute_map = new Map();
 

packages/svelte/src/compiler/phases/2-analyze/visitors/shared/element.js

@@ -79,7 +79,7 @@ export function validate_element(node, context) {
 				validate_slot_attribute(context, attribute);
 			}
 
-			if (attribute.name === 'is' && context.state.options.namespace !== 'foreign') {
+			if (attribute.name === 'is') {
 				w.attribute_avoid_is(attribute);
 			}
 

packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js

@@ -178,14 +178,6 @@ export function RegularElement(node, context) {
 		}
 	}
 
-	if (child_metadata.namespace === 'foreign') {
-		// input/select etc could mean something completely different in foreign namespace, so don't special-case them
-		needs_content_reset = false;
-		needs_input_reset = false;
-		needs_special_value_handling = false;
-		value_binding = null;
-	}
-
 	if (is_content_editable && has_content_editable_binding) {
 		child_metadata.bound_contenteditable = true;
 	}
@@ -219,7 +211,7 @@ export function RegularElement(node, context) {
 			node,
 			node_id,
 			// If value binding exists, that one takes care of calling $.init_select
-			value_binding === null && node.name === 'select' && child_metadata.namespace !== 'foreign'
+			value_binding === null && node.name === 'select'
 		);
 		is_attributes_reactive = true;
 	} else {
@@ -249,8 +241,6 @@ export function RegularElement(node, context) {
 				const value = is_text_attribute(attribute) ? attribute.value[0].data : true;
 
 				if (name !== 'class' || value) {
-					// TODO namespace=foreign probably doesn't want to do template stuff at all and instead use programmatic methods
-					// to create the elements it needs.
 					context.state.template.push(
 						` ${attribute.name}${
 							is_boolean_attribute(name) && value === true
@@ -262,10 +252,9 @@ export function RegularElement(node, context) {
 				}
 			}
 
-			const is =
-				is_custom_element && child_metadata.namespace !== 'foreign'
-					? build_custom_element_attribute_update_assignment(node_id, attribute, context)
-					: build_element_attribute_update_assignment(node, node_id, attribute, context);
+			const is = is_custom_element
+				? build_custom_element_attribute_update_assignment(node_id, attribute, context)
+				: build_element_attribute_update_assignment(node, node_id, attribute, context);
 			if (is) is_attributes_reactive = true;
 		}
 	}
@@ -301,8 +290,7 @@ export function RegularElement(node, context) {
 		locations: child_locations,
 		scope: /** @type {Scope} */ (context.state.scopes.get(node.fragment)),
 		preserve_whitespace:
-			context.state.preserve_whitespace ||
-			((node.name === 'pre' || node.name === 'textarea') && child_metadata.namespace !== 'foreign')
+			context.state.preserve_whitespace || node.name === 'pre' || node.name === 'textarea'
 	};
 
 	const { hoisted, trimmed } = clean_nodes(
@@ -587,28 +575,6 @@ function build_element_attribute_update_assignment(element, node_id, attribute,
 	const is_mathml = context.state.metadata.namespace === 'mathml';
 	let { has_call, value } = build_attribute_value(attribute.value, context);
 
-	// The foreign namespace doesn't have any special handling, everything goes through the attr function
-	if (context.state.metadata.namespace === 'foreign') {
-		const statement = b.stmt(
-			b.call(
-				'$.set_attribute',
-				node_id,
-				b.literal(name),
-				value,
-				is_ignored(element, 'hydration_attribute_changed') && b.true
-			)
-		);
-
-		if (attribute.metadata.expression.has_state) {
-			const id = state.scope.generate(`${node_id.name}_${name}`);
-			build_update_assignment(state, id, undefined, value, statement);
-			return true;
-		} else {
-			state.init.push(statement);
-			return false;
-		}
-	}
-
 	if (name === 'autofocus') {
 		state.init.push(b.stmt(b.call('$.autofocus', node_id, value)));
 		return false;

packages/svelte/src/compiler/phases/3-transform/client/visitors/SvelteElement.js

@@ -94,7 +94,7 @@ export function SvelteElement(node, context) {
 
 	const get_tag = b.thunk(/** @type {Expression} */ (context.visit(node.tag)));
 
-	if (dev && context.state.metadata.namespace !== 'foreign') {
+	if (dev) {
 		if (node.fragment.nodes.length > 0) {
 			context.state.init.push(b.stmt(b.call('$.validate_void_dynamic_element', get_tag)));
 		}

packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/element.js

@@ -116,11 +116,7 @@ export function build_attribute_value(value, context) {
  * @param {{ state: { metadata: { namespace: Namespace }}}} context
  */
 export function get_attribute_name(element, attribute, context) {
-	if (
-		!element.metadata.svg &&
-		!element.metadata.mathml &&
-		context.state.metadata.namespace !== 'foreign'
-	) {
+	if (!element.metadata.svg && !element.metadata.mathml) {
 		return normalize_attribute(attribute.name);
 	}
 

packages/svelte/src/compiler/phases/3-transform/server/visitors/RegularElement.js

@@ -21,8 +21,7 @@ export function RegularElement(node, context) {
 		...context.state,
 		namespace,
 		preserve_whitespace:
-			context.state.preserve_whitespace ||
-			((node.name === 'pre' || node.name === 'textarea') && namespace !== 'foreign')
+			context.state.preserve_whitespace || node.name === 'pre' || node.name === 'textarea'
 	};
 
 	context.state.template.push(b.literal(`<${node.name}`));
@@ -95,7 +94,7 @@ export function RegularElement(node, context) {
 		);
 	}
 
-	if (!is_void(node.name) || namespace === 'foreign') {
+	if (!is_void(node.name)) {
 		state.template.push(b.literal(`</${node.name}>`));
 	}
 

packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/element.js

@@ -268,7 +268,7 @@ export function build_element_attributes(node, context) {
  */
 function get_attribute_name(element, attribute, context) {
 	let name = attribute.name;
-	if (!element.metadata.svg && !element.metadata.mathml && context.state.namespace !== 'foreign') {
+	if (!element.metadata.svg && !element.metadata.mathml) {
 		name = name.toLowerCase();
 		// don't lookup boolean aliases here, the server runtime function does only
 		// check for the lowercase variants of boolean attributes

packages/svelte/src/compiler/phases/3-transform/utils.js

@@ -306,32 +306,30 @@ export function clean_nodes(
  * @param {Compiler.SvelteNode[]} nodes
  */
 export function infer_namespace(namespace, parent, nodes) {
-	if (namespace !== 'foreign') {
-		if (parent.type === 'RegularElement' && parent.name === 'foreignObject') {
-			return 'html';
-		}
+	if (parent.type === 'RegularElement' && parent.name === 'foreignObject') {
+		return 'html';
+	}
 
-		if (parent.type === 'RegularElement' || parent.type === 'SvelteElement') {
-			if (parent.metadata.svg) {
-				return 'svg';
-			}
-			return parent.metadata.mathml ? 'mathml' : 'html';
+	if (parent.type === 'RegularElement' || parent.type === 'SvelteElement') {
+		if (parent.metadata.svg) {
+			return 'svg';
 		}
+		return parent.metadata.mathml ? 'mathml' : 'html';
+	}
 
-		// Re-evaluate the namespace inside slot nodes that reset the namespace
-		if (
-			parent.type === 'Fragment' ||
-			parent.type === 'Root' ||
-			parent.type === 'Component' ||
-			parent.type === 'SvelteComponent' ||
-			parent.type === 'SvelteFragment' ||
-			parent.type === 'SnippetBlock' ||
-			parent.type === 'SlotElement'
-		) {
-			const new_namespace = check_nodes_for_namespace(nodes, 'keep');
-			if (new_namespace !== 'keep' && new_namespace !== 'maybe_html') {
-				return new_namespace;
-			}
+	// Re-evaluate the namespace inside slot nodes that reset the namespace
+	if (
+		parent.type === 'Fragment' ||
+		parent.type === 'Root' ||
+		parent.type === 'Component' ||
+		parent.type === 'SvelteComponent' ||
+		parent.type === 'SvelteFragment' ||
+		parent.type === 'SnippetBlock' ||
+		parent.type === 'SlotElement'
+	) {
+		const new_namespace = check_nodes_for_namespace(nodes, 'keep');
+		if (new_namespace !== 'keep' && new_namespace !== 'maybe_html') {
+			return new_namespace;
 		}
 	}
 
@@ -401,10 +399,6 @@ function check_nodes_for_namespace(nodes, namespace) {
  * @returns {Compiler.Namespace}
  */
 export function determine_namespace_for_children(node, namespace) {
-	if (namespace === 'foreign') {
-		return namespace;
-	}
-
 	if (node.name === 'foreignObject') {
 		return 'html';
 	}

packages/svelte/src/compiler/types/index.d.ts

@@ -85,7 +85,7 @@ export interface CompileOptions extends ModuleCompileOptions {
 	 */
 	accessors?: boolean;
 	/**
-	 * The namespace of the element; e.g., `"html"`, `"svg"`, `"foreign"`.
+	 * The namespace of the element; e.g., `"html"`, `"svg"`, `"mathml"`.
 	 *
 	 * @default 'html'
 	 */

packages/svelte/src/compiler/types/template.d.ts

@@ -47,11 +47,8 @@ export interface Fragment {
  * - `html`    — the default, for e.g. `<div>` or `<span>`
  * - `svg`     — for e.g. `<svg>` or `<g>`
  * - `mathml`  — for e.g. `<math>` or `<mrow>`
- * - `foreign` — for other compilation targets than the web, e.g. Svelte Native.
- *               Disallows bindings other than bind:this, disables a11y checks, disables any special attribute handling
- *               (also see https://github.com/sveltejs/svelte/pull/5652)
  */
-export type Namespace = 'html' | 'svg' | 'mathml' | 'foreign';
+export type Namespace = 'html' | 'svg' | 'mathml';
 
 export interface Root extends BaseNode {
 	type: 'Root';

packages/svelte/src/compiler/validate-options.js

@@ -90,7 +90,7 @@ export const validate_component_options =
 
 			name: string(undefined),
 
-			namespace: list(['html', 'svg', 'foreign']),
+			namespace: list(['html', 'mathml', 'svg']),
 
 			modernAst: boolean(false),