feat: Define the MountOptions type (#13674)

* feat: Define the MountOptions type

* Revert "feat: Define the MountOptions type"

This reverts commit bd3596fcba.

* feat: Define the MountOptions type

* chore: Add changeset

* lint

* lint

---------

Co-authored-by: Dominic Gannaway <dg@domgan.com>

.changeset/afraid-turtles-invent.md

@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: export mount() options as the MountOptions type

packages/svelte/src/index.d.ts

@@ -309,4 +309,42 @@ export interface EventDispatcher<EventMap extends Record<string, any>> {
 	): boolean;
 }
 
+/**
+ * Defines the options accepted by the `mount()` function.
+ */
+export type MountOptions<Props extends Record<string, any> = Record<string, any>> = {
+	/**
+	 * Target element where the component will be mounted.
+	 */
+	target: Document | Element | ShadowRoot;
+	/**
+	 * Optional node inside `target` and when specified, it is used to render the component immediately before it.
+	 */
+	anchor?: Node;
+	/**
+	 * Allows the specification of events.
+	 */
+	events?: Record<string, (e: any) => any>;
+	/**
+	 * Used to define context at the component level.
+	 */
+	context?: Map<any, any>;
+	/**
+	 * Used to control transition playback on initial render.  The default value is `true` to run transitions.
+	 */
+	intro?: boolean;
+} & ({} extends Props
+	? {
+			/**
+			 * Component properties.
+			 */
+			props?: Props;
+		}
+	: {
+			/**
+			 * Component properties.
+			 */
+			props: Props;
+		});
+
 export * from './index-client.js';

packages/svelte/src/internal/client/render.js

@@ -1,5 +1,5 @@
 /** @import { ComponentContext, Effect, TemplateNode } from '#client' */
-/** @import { Component, ComponentType, SvelteComponent } from '../../index.js' */
+/** @import { Component, ComponentType, SvelteComponent, MountOptions } from '../../index.js' */
 import { DEV } from 'esm-env';
 import {
 	clear_text_content,
@@ -65,21 +65,7 @@ export function set_text(text, value) {
  * @template {Record<string, any>} Props
  * @template {Record<string, any>} Exports
  * @param {ComponentType<SvelteComponent<Props>> | Component<Props, Exports, any>} component
- * @param {{} extends Props ? {
- * 		target: Document | Element | ShadowRoot;
- * 		anchor?: Node;
- * 		props?: Props;
- * 		events?: Record<string, (e: any) => any>;
- * 		context?: Map<any, any>;
- * 		intro?: boolean;
- * 	}: {
- * 		target: Document | Element | ShadowRoot;
- * 		props: Props;
- * 		anchor?: Node;
- * 		events?: Record<string, (e: any) => any>;
- * 		context?: Map<any, any>;
- * 		intro?: boolean;
- * 	}} options
+ * @param {MountOptions<Props>} options
  * @returns {Exports}
  */
 export function mount(component, options) {
@@ -175,14 +161,7 @@ const document_listeners = new Map();
 /**
  * @template {Record<string, any>} Exports
  * @param {ComponentType<SvelteComponent<any>> | Component<any>} Component
- * @param {{
- * 		target: Document | Element | ShadowRoot;
- * 		anchor?: Node;
- * 		props?: any;
- * 		events?: any;
- * 		context?: Map<any, any>;
- * 		intro?: boolean;
- * 	}} options
+ * @param {MountOptions} options
  * @returns {Exports}
  */
 function _mount(Component, { target, anchor, props = {}, events, context, intro = true }) {

packages/svelte/types/index.d.ts

@@ -305,6 +305,44 @@ declare module 'svelte' {
 					: [type: Type, parameter: EventMap[Type], options?: DispatchOptions]
 		): boolean;
 	}
+
+	/**
+	 * Defines the options accepted by the `mount()` function.
+	 */
+	export type MountOptions<Props extends Record<string, any> = Record<string, any>> = {
+		/**
+		 * Target element where the component will be mounted.
+		 */
+		target: Document | Element | ShadowRoot;
+		/**
+		 * Optional node inside `target` and when specified, it is used to render the component immediately before it.
+		 */
+		anchor?: Node;
+		/**
+		 * Allows the specification of events.
+		 */
+		events?: Record<string, (e: any) => any>;
+		/**
+		 * Used to define context at the component level.
+		 */
+		context?: Map<any, any>;
+		/**
+		 * Used to control transition playback on initial render.  The default value is `true` to run transitions.
+		 */
+		intro?: boolean;
+	} & ({} extends Props
+		? {
+				/**
+				 * Component properties.
+				 */
+				props?: Props;
+			}
+		: {
+				/**
+				 * Component properties.
+				 */
+				props: Props;
+			});
 	/**
 	 * The `onMount` function schedules a callback to run as soon as the component has been mounted to the DOM.
 	 * It must be called during the component's initialisation (but doesn't need to live *inside* the component;
@@ -384,21 +422,7 @@ declare module 'svelte' {
 	 * Transitions will play during the initial render unless the `intro` option is set to `false`.
 	 *
 	 * */
-	export function mount<Props extends Record<string, any>, Exports extends Record<string, any>>(component: ComponentType<SvelteComponent<Props>> | Component<Props, Exports, any>, options: {} extends Props ? {
-		target: Document | Element | ShadowRoot;
-		anchor?: Node;
-		props?: Props;
-		events?: Record<string, (e: any) => any>;
-		context?: Map<any, any>;
-		intro?: boolean;
-	} : {
-		target: Document | Element | ShadowRoot;
-		props: Props;
-		anchor?: Node;
-		events?: Record<string, (e: any) => any>;
-		context?: Map<any, any>;
-		intro?: boolean;
-	}): Exports;
+	export function mount<Props extends Record<string, any>, Exports extends Record<string, any>>(component: ComponentType<SvelteComponent<Props>> | Component<Props, Exports, any>, options: MountOptions<Props>): Exports;
 	/**
 	 * Hydrates a component on the given target and returns the exports and potentially the props (if compiled with `accessors: true`) of the component
 	 *