Make animation/transition params optional

They are not needed for most of the functions and should be marked as optional accordingly to make TypeScript users happy.

Fixes https://github.com/sveltejs/language-tools/issues/785

src/runtime/animate/index.ts

@@ -16,7 +16,7 @@ interface FlipParams {
 	easing?: (t: number) => number;
 }
 
-export function flip(node: Element, animation: { from: DOMRect; to: DOMRect }, params: FlipParams): AnimationConfig {
+export function flip(node: Element, animation: { from: DOMRect; to: DOMRect }, params: FlipParams = {}): AnimationConfig {
 	const style = getComputedStyle(node);
 	const transform = style.transform === 'none' ? '' : style.transform;
 	const scaleX = animation.from.width / node.clientWidth;

src/runtime/transition/index.ts

@@ -25,7 +25,7 @@ export function blur(node: Element, {
 	easing = cubicInOut,
 	amount = 5,
 	opacity = 0
-}: BlurParams): TransitionConfig {
+}: BlurParams = {}): TransitionConfig {
 	const style = getComputedStyle(node);
 	const target_opacity = +style.opacity;
 	const f = style.filter === 'none' ? '' : style.filter;
@@ -50,7 +50,7 @@ export function fade(node: Element, {
 	delay = 0,
 	duration = 400,
 	easing = linear
-}: FadeParams): TransitionConfig {
+}: FadeParams = {}): TransitionConfig {
 	const o = +getComputedStyle(node).opacity;
 
 	return {
@@ -77,7 +77,7 @@ export function fly(node: Element, {
 	x = 0,
 	y = 0,
 	opacity = 0
-}: FlyParams): TransitionConfig {
+}: FlyParams = {}): TransitionConfig {
 	const style = getComputedStyle(node);
 	const target_opacity = +style.opacity;
 	const transform = style.transform === 'none' ? '' : style.transform;
@@ -104,7 +104,7 @@ export function slide(node: Element, {
 	delay = 0,
 	duration = 400,
 	easing = cubicOut
-}: SlideParams): TransitionConfig {
+}: SlideParams = {}): TransitionConfig {
 	const style = getComputedStyle(node);
 	const opacity = +style.opacity;
 	const height = parseFloat(style.height);
@@ -146,7 +146,7 @@ export function scale(node: Element, {
 	easing = cubicOut,
 	start = 0,
 	opacity = 0
-}: ScaleParams): TransitionConfig {
+}: ScaleParams = {}): TransitionConfig {
 	const style = getComputedStyle(node);
 	const target_opacity = +style.opacity;
 	const transform = style.transform === 'none' ? '' : style.transform;
@@ -177,7 +177,7 @@ export function draw(node: SVGElement & { getTotalLength(): number }, {
 	speed,
 	duration,
 	easing = cubicInOut
-}: DrawParams): TransitionConfig {
+}: DrawParams = {}): TransitionConfig {
 	const len = node.getTotalLength();
 
 	if (duration === undefined) {