From 19e4a4fdf3d2bff0caa551236cff10e4df5ff3cd Mon Sep 17 00:00:00 2001
From: Walker Lockard <walker.b.lockard@gmail.com>
Date: Sun, 16 May 2021 01:39:39 -0500
Subject: [PATCH 1/5] Update tutorial text.md (#6329)

The component referenced in text.md is no longer on line 33 of the provided code.
---
 .../tutorial/16-special-elements/03-svelte-window/text.md       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/site/content/tutorial/16-special-elements/03-svelte-window/text.md b/site/content/tutorial/16-special-elements/03-svelte-window/text.md
index b581b3ada4..3c6c71a730 100644
--- a/site/content/tutorial/16-special-elements/03-svelte-window/text.md
+++ b/site/content/tutorial/16-special-elements/03-svelte-window/text.md
@@ -4,7 +4,7 @@ title: <svelte:window>
 
 Just as you can add event listeners to any DOM element, you can add event listeners to the `window` object with `<svelte:window>`.
 
-On line 33, add the `keydown` listener:
+On line 11, add the `keydown` listener:
 
 ```html
 <svelte:window on:keydown={handleKeydown}/>

From 58b897fc83450f9ca129306f26ac3b8ee94f3e56 Mon Sep 17 00:00:00 2001
From: Lawrence Logoh <Lawrence.logoh@gmail.com>
Date: Sun, 16 May 2021 12:16:24 +0000
Subject: [PATCH 2/5] updated select-bindings text.md (#6333)

Referenced line is now 20 instead of 24
---
 site/content/tutorial/06-bindings/06-select-bindings/text.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/site/content/tutorial/06-bindings/06-select-bindings/text.md b/site/content/tutorial/06-bindings/06-select-bindings/text.md
index f4972557ab..b9cf2de6ec 100644
--- a/site/content/tutorial/06-bindings/06-select-bindings/text.md
+++ b/site/content/tutorial/06-bindings/06-select-bindings/text.md
@@ -2,7 +2,7 @@
 title: Select bindings
 ---
 
-We can also use `bind:value` with `<select>` elements. Update line 24:
+We can also use `bind:value` with `<select>` elements. Update line 20:
 
 ```html
 <select bind:value={selected} on:change="{() => answer = ''}">
@@ -10,4 +10,4 @@ We can also use `bind:value` with `<select>` elements. Update line 24:
 
 Note that the `<option>` values are objects rather than strings. Svelte doesn't mind.
 
-> Because we haven't set an initial value of `selected`, the binding will set it to the default value (the first in the list) automatically. Be careful though — until the binding is initialised, `selected` remains undefined, so we can't blindly reference e.g. `selected.id` in the template.
\ No newline at end of file
+> Because we haven't set an initial value of `selected`, the binding will set it to the default value (the first in the list) automatically. Be careful though — until the binding is initialised, `selected` remains undefined, so we can't blindly reference e.g. `selected.id` in the template.

From b11f5b12f5055e363af0c03c1343fa721504f632 Mon Sep 17 00:00:00 2001
From: Ajit Krishna <ajitkrishna99@gmail.com>
Date: Tue, 18 May 2021 22:27:44 +0800
Subject: [PATCH 3/5] Update <svelte:options> copy (#6339)

<svelte:options> is not the last lesson in "Special Elements"
---
 .../tutorial/16-special-elements/07-svelte-options/text.md    | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/site/content/tutorial/16-special-elements/07-svelte-options/text.md b/site/content/tutorial/16-special-elements/07-svelte-options/text.md
index 60a9d3b0f8..c3f9f50ce0 100644
--- a/site/content/tutorial/16-special-elements/07-svelte-options/text.md
+++ b/site/content/tutorial/16-special-elements/07-svelte-options/text.md
@@ -2,7 +2,7 @@
 title: <svelte:options>
 ---
 
-Lastly, `<svelte:options>` allows you to specify compiler options.
+The `<svelte:options>` element allows you to specify compiler options.
 
 We'll use the `immutable` option as an example. In this app, the `<Todo>` component flashes whenever it receives new data. Clicking on one of the items toggles its `done` state by creating an updated `todos` array. This causes the *other* `<Todo>` items to flash, even though they don't end up making any changes to the DOM.
 
@@ -27,4 +27,4 @@ The options that can be set here are:
 * `namespace="..."` — the namespace where this component will be used, most commonly `"svg"`
 * `tag="..."` — the name to use when compiling this component as a custom element
 
-Consult the [API reference](docs) for more information on these options.
\ No newline at end of file
+Consult the [API reference](docs) for more information on these options.

From 3301b0961916b748866662af8b56d682a5cc0656 Mon Sep 17 00:00:00 2001
From: Adam Alexander <49114586+ogre-yoga@users.noreply.github.com>
Date: Wed, 19 May 2021 19:40:42 +1000
Subject: [PATCH 4/5] Fix tutorial instructions refer to wrong line number in
 code (#6342)

Instructions refer to wrong line number

Video element is not on line 116, it's on line 58
---
 site/content/tutorial/06-bindings/10-media-elements/text.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/site/content/tutorial/06-bindings/10-media-elements/text.md b/site/content/tutorial/06-bindings/10-media-elements/text.md
index 0a854f19e9..5b1cb4ef8d 100644
--- a/site/content/tutorial/06-bindings/10-media-elements/text.md
+++ b/site/content/tutorial/06-bindings/10-media-elements/text.md
@@ -4,7 +4,7 @@ title: Media elements
 
 The `<audio>` and `<video>` elements have several properties that you can bind to. This example demonstrates a few of them.
 
-On line 116, add `currentTime={time}`, `duration` and `paused` bindings:
+On line 58, add `currentTime={time}`, `duration` and `paused` bindings:
 
 ```html
 <video
@@ -41,4 +41,4 @@ The complete set of bindings for `<audio>` and `<video>` is as follows — six *
 * `volume` — a value between 0 and 1
 * `muted` — a boolean value where true is muted
 
-Videos additionally have readonly `videoWidth` and `videoHeight` bindings.
\ No newline at end of file
+Videos additionally have readonly `videoWidth` and `videoHeight` bindings.

From b295d68ec696a00e4d52cc7f86fed149b13062d2 Mon Sep 17 00:00:00 2001
From: Ignatius Bagus <ignatius.mbs@gmail.com>
Date: Thu, 20 May 2021 20:31:51 +0700
Subject: [PATCH 5/5] fix types: allow writable/readable empty initialization
 (#6293)

Fixes #6291
Fixes #6345

Both writable and readable initialized without any arguments are already valid, but TS complains about it. This makes both allowed to be emptily initialized. It's also possible to invoke readable with one argument only.
---
 CHANGELOG.md                      |  4 ++++
 site/content/docs/03-run-time.md  | 10 ++++----
 src/runtime/store/index.ts        |  4 ++--
 test/store/{index.js => index.ts} | 39 +++++++++++++++++++++++++++++++
 4 files changed, 49 insertions(+), 8 deletions(-)
 rename test/store/{index.js => index.ts} (90%)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 141d5661bc..89249634bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Svelte changelog
 
+## Unreleased
+
+* Fix type signatures of `writable` and `readable`. It's possible to invoke them without arguments ([#6291](https://github.com/sveltejs/svelte/issues/6291), [#6345](https://github.com/sveltejs/svelte/issues/6345))
+
 ## 3.38.2
 
 * Revert hydration optimisation for the time being ([#6279](https://github.com/sveltejs/svelte/issues/6279))
diff --git a/site/content/docs/03-run-time.md b/site/content/docs/03-run-time.md
index 7fbc8850de..c0bd145316 100644
--- a/site/content/docs/03-run-time.md
+++ b/site/content/docs/03-run-time.md
@@ -245,10 +245,10 @@ This makes it possible to wrap almost any other reactive state handling library
 #### `writable`
 
 ```js
-store = writable(value: any)
+store = writable(value?: any)
 ```
 ```js
-store = writable(value: any, (set: (value: any) => void) => () => void)
+store = writable(value?: any, start?: (set: (value: any) => void) => () => void)
 ```
 
 ---
@@ -297,14 +297,12 @@ unsubscribe(); // logs 'no more subscribers'
 #### `readable`
 
 ```js
-store = readable(value: any, (set: (value: any) => void) => () => void)
+store = readable(value?: any, start?: (set: (value: any) => void) => () => void)
 ```
 
 ---
 
-Creates a store whose value cannot be set from 'outside', the first argument is the store's initial value.
-
-The second argument to `readable` is the same as the second argument to `writable`, except that it is required with `readable` (since otherwise there would be no way to update the store value).
+Creates a store whose value cannot be set from 'outside', the first argument is the store's initial value, and the second argument to `readable` is the same as the second argument to `writable`.
 
 ```js
 import { readable } from 'svelte/store';
diff --git a/src/runtime/store/index.ts b/src/runtime/store/index.ts
index cf15db5250..213a4ff6fd 100644
--- a/src/runtime/store/index.ts
+++ b/src/runtime/store/index.ts
@@ -50,7 +50,7 @@ const subscriber_queue = [];
  * @param value initial value
  * @param {StartStopNotifier}start start and stop notifications for subscriptions
  */
-export function readable<T>(value: T, start: StartStopNotifier<T>): Readable<T> {
+export function readable<T>(value?: T, start?: StartStopNotifier<T>): Readable<T> {
 	return {
 		subscribe: writable(value, start).subscribe
 	};
@@ -61,7 +61,7 @@ export function readable<T>(value: T, start: StartStopNotifier<T>): Readable<T>
  * @param {*=}value initial value
  * @param {StartStopNotifier=}start start and stop notifications for subscriptions
  */
-export function writable<T>(value: T, start: StartStopNotifier<T> = noop): Writable<T> {
+export function writable<T>(value?: T, start: StartStopNotifier<T> = noop): Writable<T> {
 	let stop: Unsubscriber;
 	const subscribers: Array<SubscribeInvalidateTuple<T>> = [];
 
diff --git a/test/store/index.js b/test/store/index.ts
similarity index 90%
rename from test/store/index.js
rename to test/store/index.ts
index 2af4a6f35d..b6fc5940e1 100644
--- a/test/store/index.js
+++ b/test/store/index.ts
@@ -22,6 +22,19 @@ describe('store', () => {
 			assert.deepEqual(values, [0, 1, 2]);
 		});
 
+		it('creates an undefined writable store', () => {
+			const store = writable();
+			const values = [];
+
+			const unsubscribe = store.subscribe(value => {
+				values.push(value);
+			});
+
+			unsubscribe();
+
+			assert.deepEqual(values, [undefined]);
+		});
+
 		it('calls provided subscribe handler', () => {
 			let called = 0;
 
@@ -114,6 +127,32 @@ describe('store', () => {
 
 			assert.deepEqual(values, [0, 1, 2]);
 		});
+
+		it('creates an undefined readable store', () => {
+			const store = readable();
+			const values = [];
+
+			const unsubscribe = store.subscribe(value => {
+				values.push(value);
+			});
+
+			unsubscribe();
+
+			assert.deepEqual(values, [undefined]);
+		});
+
+		it('creates a readable store without updater', () => {
+			const store = readable(100);
+			const values = [];
+
+			const unsubscribe = store.subscribe(value => {
+				values.push(value);
+			});
+
+			unsubscribe();
+
+			assert.deepEqual(values, [100]);
+		});
 	});
 
 	const fake_observable = {