diff --git a/src/runtime/transition/index.ts b/src/runtime/transition/index.ts
index 01f5931411..a2be38c4a6 100644
--- a/src/runtime/transition/index.ts
+++ b/src/runtime/transition/index.ts
@@ -1,289 +1,254 @@
 import { cubicOut, cubicInOut, linear } from '../easing';
 import { assign, split_css_unit, is_function } from '../internal';
-
-export type EasingFunction = (t: number) => number;
-
-export interface TransitionConfig {
-	delay?: number;
-	duration?: number;
-	easing?: EasingFunction;
-	css?: (t: number, u: number) => string;
-	tick?: (t: number, u: number) => void;
-}
-
-export interface BlurParams {
-	delay?: number;
-	duration?: number;
-	easing?: EasingFunction;
-	amount?: number | string;
-	opacity?: number;
+/** @param {Element} node
+ * @param {BlurParams}
+ * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+ */
+export function blur(node, { delay = 0, duration = 400, easing = cubicInOut, amount = 5, opacity = 0 } = {}) {
+    const style = getComputedStyle(node);
+    const target_opacity = +style.opacity;
+    const f = style.filter === 'none' ? '' : style.filter;
+    const od = target_opacity * (1 - opacity);
+    const [value, unit] = split_css_unit(amount);
+    return {
+        delay,
+        duration,
+        easing,
+        css: (_t, u) => `opacity: ${target_opacity - od * u}; filter: ${f} blur(${u * value}${unit});`
+    };
 }
-
-export function blur(
-	node: Element,
-	{ delay = 0, duration = 400, easing = cubicInOut, amount = 5, opacity = 0 }: BlurParams = {}
-): TransitionConfig {
-	const style = getComputedStyle(node);
-	const target_opacity = +style.opacity;
-	const f = style.filter === 'none' ? '' : style.filter;
-
-	const od = target_opacity * (1 - opacity);
-	const [value, unit] = split_css_unit(amount);
-	return {
-		delay,
-		duration,
-		easing,
-		css: (_t, u) => `opacity: ${target_opacity - od * u}; filter: ${f} blur(${u * value}${unit});`
-	};
-}
-
-export interface FadeParams {
-	delay?: number;
-	duration?: number;
-	easing?: EasingFunction;
-}
-
-export function fade(
-	node: Element,
-	{ delay = 0, duration = 400, easing = linear }: FadeParams = {}
-): TransitionConfig {
-	const o = +getComputedStyle(node).opacity;
-
-	return {
-		delay,
-		duration,
-		easing,
-		css: (t) => `opacity: ${t * o}`
-	};
+/** @param {Element} node
+ * @param {FadeParams}
+ * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+ */
+export function fade(node, { delay = 0, duration = 400, easing = linear } = {}) {
+    const o = +getComputedStyle(node).opacity;
+    return {
+        delay,
+        duration,
+        easing,
+        css: (t) => `opacity: ${t * o}`
+    };
 }
-
-export interface FlyParams {
-	delay?: number;
-	duration?: number;
-	easing?: EasingFunction;
-	x?: number | string;
-	y?: number | string;
-	opacity?: number;
-}
-
-export function fly(
-	node: Element,
-	{ delay = 0, duration = 400, easing = cubicOut, x = 0, y = 0, opacity = 0 }: FlyParams = {}
-): TransitionConfig {
-	const style = getComputedStyle(node);
-	const target_opacity = +style.opacity;
-	const transform = style.transform === 'none' ? '' : style.transform;
-
-	const od = target_opacity * (1 - opacity);
-	const [xValue, xUnit] = split_css_unit(x);
-	const [yValue, yUnit] = split_css_unit(y);
-	return {
-		delay,
-		duration,
-		easing,
-		css: (t, u) => `
+/** @param {Element} node
+ * @param {FlyParams}
+ * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+ */
+export function fly(node, { delay = 0, duration = 400, easing = cubicOut, x = 0, y = 0, opacity = 0 } = {}) {
+    const style = getComputedStyle(node);
+    const target_opacity = +style.opacity;
+    const transform = style.transform === 'none' ? '' : style.transform;
+    const od = target_opacity * (1 - opacity);
+    const [xValue, xUnit] = split_css_unit(x);
+    const [yValue, yUnit] = split_css_unit(y);
+    return {
+        delay,
+        duration,
+        easing,
+        css: (t, u) => `
 			transform: ${transform} translate(${(1 - t) * xValue}${xUnit}, ${(1 - t) * yValue}${yUnit});
 			opacity: ${target_opacity - od * u}`
-	};
-}
-
-export interface SlideParams {
-	delay?: number;
-	duration?: number;
-	easing?: EasingFunction;
-	axis?: 'x' | 'y';
+    };
 }
-
-export function slide(
-	node: Element,
-	{ delay = 0, duration = 400, easing = cubicOut, axis = 'y' }: SlideParams = {}
-): TransitionConfig {
-	const style = getComputedStyle(node);
-	const opacity = +style.opacity;
-	const primary_property = axis === 'y' ? 'height' : 'width';
-	const primary_property_value = parseFloat(style[primary_property]);
-	const secondary_properties = axis === 'y' ? ['top', 'bottom'] : ['left', 'right'];
-	const capitalized_secondary_properties = secondary_properties.map(
-		(e) => `${e[0].toUpperCase()}${e.slice(1)}`
-	);
-	const padding_start_value = parseFloat(style[`padding${capitalized_secondary_properties[0]}`]);
-	const padding_end_value = parseFloat(style[`padding${capitalized_secondary_properties[1]}`]);
-	const margin_start_value = parseFloat(style[`margin${capitalized_secondary_properties[0]}`]);
-	const margin_end_value = parseFloat(style[`margin${capitalized_secondary_properties[1]}`]);
-	const border_width_start_value = parseFloat(
-		style[`border${capitalized_secondary_properties[0]}Width`]
-	);
-	const border_width_end_value = parseFloat(
-		style[`border${capitalized_secondary_properties[1]}Width`]
-	);
-	return {
-		delay,
-		duration,
-		easing,
-		css: (t) =>
-			'overflow: hidden;' +
-			`opacity: ${Math.min(t * 20, 1) * opacity};` +
-			`${primary_property}: ${t * primary_property_value}px;` +
-			`padding-${secondary_properties[0]}: ${t * padding_start_value}px;` +
-			`padding-${secondary_properties[1]}: ${t * padding_end_value}px;` +
-			`margin-${secondary_properties[0]}: ${t * margin_start_value}px;` +
-			`margin-${secondary_properties[1]}: ${t * margin_end_value}px;` +
-			`border-${secondary_properties[0]}-width: ${t * border_width_start_value}px;` +
-			`border-${secondary_properties[1]}-width: ${t * border_width_end_value}px;`
-	};
+/** @param {Element} node
+ * @param {SlideParams}
+ * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+ */
+export function slide(node, { delay = 0, duration = 400, easing = cubicOut, axis = 'y' } = {}) {
+    const style = getComputedStyle(node);
+    const opacity = +style.opacity;
+    const primary_property = axis === 'y' ? 'height' : 'width';
+    const primary_property_value = parseFloat(style[primary_property]);
+    const secondary_properties = axis === 'y' ? ['top', 'bottom'] : ['left', 'right'];
+    const capitalized_secondary_properties = secondary_properties.map((e) => `${e[0].toUpperCase()}${e.slice(1)}`);
+    const padding_start_value = parseFloat(style[`padding${capitalized_secondary_properties[0]}`]);
+    const padding_end_value = parseFloat(style[`padding${capitalized_secondary_properties[1]}`]);
+    const margin_start_value = parseFloat(style[`margin${capitalized_secondary_properties[0]}`]);
+    const margin_end_value = parseFloat(style[`margin${capitalized_secondary_properties[1]}`]);
+    const border_width_start_value = parseFloat(style[`border${capitalized_secondary_properties[0]}Width`]);
+    const border_width_end_value = parseFloat(style[`border${capitalized_secondary_properties[1]}Width`]);
+    return {
+        delay,
+        duration,
+        easing,
+        css: (t) => 'overflow: hidden;' +
+            `opacity: ${Math.min(t * 20, 1) * opacity};` +
+            `${primary_property}: ${t * primary_property_value}px;` +
+            `padding-${secondary_properties[0]}: ${t * padding_start_value}px;` +
+            `padding-${secondary_properties[1]}: ${t * padding_end_value}px;` +
+            `margin-${secondary_properties[0]}: ${t * margin_start_value}px;` +
+            `margin-${secondary_properties[1]}: ${t * margin_end_value}px;` +
+            `border-${secondary_properties[0]}-width: ${t * border_width_start_value}px;` +
+            `border-${secondary_properties[1]}-width: ${t * border_width_end_value}px;`
+    };
 }
-
-export interface ScaleParams {
-	delay?: number;
-	duration?: number;
-	easing?: EasingFunction;
-	start?: number;
-	opacity?: number;
-}
-
-export function scale(
-	node: Element,
-	{ delay = 0, duration = 400, easing = cubicOut, start = 0, opacity = 0 }: ScaleParams = {}
-): TransitionConfig {
-	const style = getComputedStyle(node);
-	const target_opacity = +style.opacity;
-	const transform = style.transform === 'none' ? '' : style.transform;
-
-	const sd = 1 - start;
-	const od = target_opacity * (1 - opacity);
-
-	return {
-		delay,
-		duration,
-		easing,
-		css: (_t, u) => `
+/** @param {Element} node
+ * @param {ScaleParams}
+ * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+ */
+export function scale(node, { delay = 0, duration = 400, easing = cubicOut, start = 0, opacity = 0 } = {}) {
+    const style = getComputedStyle(node);
+    const target_opacity = +style.opacity;
+    const transform = style.transform === 'none' ? '' : style.transform;
+    const sd = 1 - start;
+    const od = target_opacity * (1 - opacity);
+    return {
+        delay,
+        duration,
+        easing,
+        css: (_t, u) => `
 			transform: ${transform} scale(${1 - sd * u});
 			opacity: ${target_opacity - od * u}
 		`
-	};
+    };
 }
-
-export interface DrawParams {
-	delay?: number;
-	speed?: number;
-	duration?: number | ((len: number) => number);
-	easing?: EasingFunction;
-}
-
-export function draw(
-	node: SVGElement & { getTotalLength(): number },
-	{ delay = 0, speed, duration, easing = cubicInOut }: DrawParams = {}
-): TransitionConfig {
-	let len = node.getTotalLength();
-	const style = getComputedStyle(node);
-	if (style.strokeLinecap !== 'butt') {
-		len += parseInt(style.strokeWidth);
-	}
-
-	if (duration === undefined) {
-		if (speed === undefined) {
-			duration = 800;
-		} else {
-			duration = len / speed;
-		}
-	} else if (typeof duration === 'function') {
-		duration = duration(len);
-	}
-
-	return {
-		delay,
-		duration,
-		easing,
-		css: (_, u) => `
+/** @param {SVGElement & { getTotalLength(): number }} node
+ * @param {DrawParams}
+ * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+ */
+export function draw(node, { delay = 0, speed, duration, easing = cubicInOut } = {}) {
+    let len = node.getTotalLength();
+    const style = getComputedStyle(node);
+    if (style.strokeLinecap !== 'butt') {
+        len += parseInt(style.strokeWidth);
+    }
+    if (duration === undefined) {
+        if (speed === undefined) {
+            duration = 800;
+        }
+        else {
+            duration = len / speed;
+        }
+    }
+    else if (typeof duration === 'function') {
+        duration = duration(len);
+    }
+    return {
+        delay,
+        duration,
+        easing,
+        css: (_, u) => `
 			stroke-dasharray: ${len};
 			stroke-dashoffset: ${u * len};
 		`
-	};
+    };
 }
-
-export interface CrossfadeParams {
-	delay?: number;
-	duration?: number | ((len: number) => number);
-	easing?: EasingFunction;
-}
-
-type ClientRectMap = Map<any, Element>;
-
-export function crossfade({
-	fallback,
-	...defaults
-}: CrossfadeParams & {
-	fallback?: (node: Element, params: CrossfadeParams, intro: boolean) => TransitionConfig;
-}): [
-	(
-		node: Element,
-		params: CrossfadeParams & {
-			key: any;
-		}
-	) => () => TransitionConfig,
-	(
-		node: Element,
-		params: CrossfadeParams & {
-			key: any;
-		}
-	) => () => TransitionConfig
-] {
-	const to_receive: ClientRectMap = new Map();
-	const to_send: ClientRectMap = new Map();
-
-	function crossfade(from_node: Element, node: Element, params: CrossfadeParams): TransitionConfig {
-		const {
-			delay = 0,
-			duration = (d) => Math.sqrt(d) * 30,
-			easing = cubicOut
-		} = assign(assign({}, defaults), params);
-
-		const from = from_node.getBoundingClientRect();
-		const to = node.getBoundingClientRect();
-		const dx = from.left - to.left;
-		const dy = from.top - to.top;
-		const dw = from.width / to.width;
-		const dh = from.height / to.height;
-		const d = Math.sqrt(dx * dx + dy * dy);
-
-		const style = getComputedStyle(node);
-		const transform = style.transform === 'none' ? '' : style.transform;
-		const opacity = +style.opacity;
-
-		return {
-			delay,
-			duration: is_function(duration) ? duration(d) : duration,
-			easing,
-			css: (t, u) => `
+/**
+ * @param {CrossfadeParams & {
+ * 	fallback?: (node: Element, params: CrossfadeParams, intro: boolean) => TransitionConfig;
+ * }}
+ * @returns {[(node: any, params: import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").CrossfadeParams & { key: any; }) => () => import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig, (node: any, params: import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").CrossfadeParams & { key: any; }) => () => import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig]}
+ */
+export function crossfade({ fallback, ...defaults }) {
+    /** @type {ClientRectMap} */
+    const to_receive = new Map();
+    /** @type {ClientRectMap} */
+    const to_send = new Map();
+    /** @param {Element} from_node
+     * @param {Element} node
+     * @param {CrossfadeParams} params
+     * @returns {import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+     */
+    function crossfade(from_node, node, params) {
+        const { delay = 0, duration = (d) => Math.sqrt(d) * 30, easing = cubicOut } = assign(assign({}, defaults), params);
+        const from = from_node.getBoundingClientRect();
+        const to = node.getBoundingClientRect();
+        const dx = from.left - to.left;
+        const dy = from.top - to.top;
+        const dw = from.width / to.width;
+        const dh = from.height / to.height;
+        const d = Math.sqrt(dx * dx + dy * dy);
+        const style = getComputedStyle(node);
+        const transform = style.transform === 'none' ? '' : style.transform;
+        const opacity = +style.opacity;
+        return {
+            delay,
+            duration: is_function(duration) ? duration(d) : duration,
+            easing,
+            css: (t, u) => `
 				opacity: ${t * opacity};
 				transform-origin: top left;
-				transform: ${transform} translate(${u * dx}px,${u * dy}px) scale(${t + (1 - t) * dw}, ${
-				t + (1 - t) * dh
-			});
+				transform: ${transform} translate(${u * dx}px,${u * dy}px) scale(${t + (1 - t) * dw}, ${t + (1 - t) * dh});
 			`
-		};
-	}
-
-	function transition(items: ClientRectMap, counterparts: ClientRectMap, intro: boolean) {
-		return (node: Element, params: CrossfadeParams & { key: any }) => {
-			items.set(params.key, node);
-
-			return () => {
-				if (counterparts.has(params.key)) {
-					const other_node = counterparts.get(params.key);
-					counterparts.delete(params.key);
-
-					return crossfade(other_node, node, params);
-				}
+        };
+    }
+    /** @param {ClientRectMap} items
+     * @param {ClientRectMap} counterparts
+     * @param {boolean} intro
+     * @returns {(node: any, params: import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").CrossfadeParams & { key: any; }) => () => import("/Users/elliottjohnson/dev/sveltejs/svelte/index.ts-to-jsdoc").TransitionConfig}
+     */
+    function transition(items, counterparts, intro) {
+        return (node, params) => {
+            items.set(params.key, node);
+            return () => {
+                if (counterparts.has(params.key)) {
+                    const other_node = counterparts.get(params.key);
+                    counterparts.delete(params.key);
+                    return crossfade(other_node, node, params);
+                }
+                // if the node is disappearing altogether
+                // (i.e. wasn't claimed by the other list)
+                // then we need to supply an outro
+                items.delete(params.key);
+                return fallback && fallback(node, params, intro);
+            };
+        };
+    }
+    return [transition(to_send, to_receive, false), transition(to_receive, to_send, true)];
+}
 
-				// if the node is disappearing altogether
-				// (i.e. wasn't claimed by the other list)
-				// then we need to supply an outro
-				items.delete(params.key);
-				return fallback && fallback(node, params, intro);
-			};
-		};
-	}
 
-	return [transition(to_send, to_receive, false), transition(to_receive, to_send, true)];
-}
+/** @typedef {(t: number) => number} EasingFunction */
+/** @typedef {Map<any, Element>} ClientRectMap */
+
+/** @typedef {Object} TransitionConfig
+ * @property {number} [delay]
+ * @property {number} [duration]
+ * @property {EasingFunction} [easing]
+ * @property {(t:number,u:number)=>string} [css]
+ * @property {(t:number,u:number)=>void} [tick] 
+ */
+/** @typedef {Object} BlurParams
+ * @property {number} [delay]
+ * @property {number} [duration]
+ * @property {EasingFunction} [easing]
+ * @property {number|string} [amount]
+ * @property {number} [opacity] 
+ */
+/** @typedef {Object} FadeParams
+ * @property {number} [delay]
+ * @property {number} [duration]
+ * @property {EasingFunction} [easing] 
+ */
+/** @typedef {Object} FlyParams
+ * @property {number} [delay]
+ * @property {number} [duration]
+ * @property {EasingFunction} [easing]
+ * @property {number|string} [x]
+ * @property {number|string} [y]
+ * @property {number} [opacity] 
+ */
+/** @typedef {Object} SlideParams
+ * @property {number} [delay]
+ * @property {number} [duration]
+ * @property {EasingFunction} [easing]
+ * @property {'x'|'y'} [axis] 
+ */
+/** @typedef {Object} ScaleParams
+ * @property {number} [delay]
+ * @property {number} [duration]
+ * @property {EasingFunction} [easing]
+ * @property {number} [start]
+ * @property {number} [opacity] 
+ */
+/** @typedef {Object} DrawParams
+ * @property {number} [delay]
+ * @property {number} [speed]
+ * @property {number|((len:number)=>number)} [duration]
+ * @property {EasingFunction} [easing] 
+ */
+/** @typedef {Object} CrossfadeParams
+ * @property {number} [delay]
+ * @property {number|((len:number)=>number)} [duration]
+ * @property {EasingFunction} [easing] 
+ */
\ No newline at end of file