From 2925e5bae92225258201f5f370597604a42af816 Mon Sep 17 00:00:00 2001
From: soleuniverse <dev@soleuniverse.me>
Date: Sat, 27 Jun 2026 07:11:16 +0200
Subject: [PATCH 1/5] feat: add has to createContext return and update API
 types

---
 .../docs/98-reference/.generated/shared-errors.md          | 2 +-
 packages/svelte/src/internal/client/context.js             | 7 ++++---
 packages/svelte/src/internal/server/context.js             | 5 +++--
 packages/svelte/types/index.d.ts                           | 4 ++--
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/documentation/docs/98-reference/.generated/shared-errors.md b/documentation/docs/98-reference/.generated/shared-errors.md
index 739bd58b35f5..9ab05262e74e 100644
--- a/documentation/docs/98-reference/.generated/shared-errors.md
+++ b/documentation/docs/98-reference/.generated/shared-errors.md
@@ -78,7 +78,7 @@ Certain lifecycle methods can only be used during component initialisation. To f
 Context was not set in a parent component
 ```
 
-The [`createContext()`](svelte#createContext) utility returns a `[get, set]` pair of functions. `get` will throw an error if `set` was not used to set the context in a parent component.
+The [`createContext()`](svelte#createContext) utility returns a `[get, set, has]` triplet of functions. `get` will throw an error if `set` was not used to set the context in a parent component.
 
 ### snippet_without_render_tag
 
diff --git a/packages/svelte/src/internal/client/context.js b/packages/svelte/src/internal/client/context.js
index 0baef5c63e5c..524bd4cd06b7 100644
--- a/packages/svelte/src/internal/client/context.js
+++ b/packages/svelte/src/internal/client/context.js
@@ -70,12 +70,12 @@ export function set_dev_current_component_function(fn) {
 }
 
 /**
- * Returns a `[get, set]` pair of functions for working with context in a type-safe way.
+ * Returns a `[get, set, has]` triplet of functions for working with context in a type-safe way.
  *
  * `get` will throw an error if no parent component called `set`.
  *
  * @template T
- * @returns {[() => T, (context: T) => T]}
+ * @returns {[() => T, (context: T) => T, () => boolean]}
  * @since 5.40.0
  */
 export function createContext() {
@@ -89,7 +89,8 @@ export function createContext() {
 
 			return getContext(key);
 		},
-		(context) => setContext(key, context)
+		(context) => setContext(key, context),
+		() => hasContext(key)
 	];
 }
 
diff --git a/packages/svelte/src/internal/server/context.js b/packages/svelte/src/internal/server/context.js
index 6a7dc1f88323..18d193478350 100644
--- a/packages/svelte/src/internal/server/context.js
+++ b/packages/svelte/src/internal/server/context.js
@@ -12,7 +12,7 @@ export function set_ssr_context(v) {
 
 /**
  * @template T
- * @returns {[() => T, (context: T) => T]}
+ * @returns {[() => T, (context: T) => T, () => boolean]}
  * @since 5.40.0
  */
 export function createContext() {
@@ -26,7 +26,8 @@ export function createContext() {
 
 			return getContext(key);
 		},
-		(context) => setContext(key, context)
+		(context) => setContext(key, context),
+		() => hasContext(key)
 	];
 }
 
diff --git a/packages/svelte/types/index.d.ts b/packages/svelte/types/index.d.ts
index 5f41fabf60cd..1cccb7b5f807 100644
--- a/packages/svelte/types/index.d.ts
+++ b/packages/svelte/types/index.d.ts
@@ -492,13 +492,13 @@ declare module 'svelte' {
 	 */
 	export function fork(fn: () => void): Fork;
 	/**
-	 * Returns a `[get, set]` pair of functions for working with context in a type-safe way.
+	 * Returns a `[get, set, has]` triplet of functions for working with context in a type-safe way.
 	 *
 	 * `get` will throw an error if no parent component called `set`.
 	 *
 	 * @since 5.40.0
 	 */
-	export function createContext<T>(): [() => T, (context: T) => T];
+	export function createContext<T>(): [() => T, (context: T) => T, () => boolean];
 	/**
 	 * Retrieves the context that belongs to the closest parent component with the specified `key`.
 	 * Must be called during component initialisation.

From acfe39bcb1b26a2c4d574a073c9963989c935089 Mon Sep 17 00:00:00 2001
From: soleuniverse <dev@soleuniverse.me>
Date: Sat, 27 Jun 2026 07:12:31 +0200
Subject: [PATCH 2/5] test: has function in createContext test samples

---
 .../samples/create-context-programmatic/Child.svelte |  5 ++++-
 .../samples/create-context-programmatic/_config.js   |  2 +-
 .../samples/create-context-programmatic/main.svelte  | 12 +++++++-----
 .../samples/create-context/Child.svelte              |  5 ++++-
 .../runtime-runes/samples/create-context/_config.js  |  2 +-
 .../runtime-runes/samples/create-context/main.svelte |  4 ++--
 6 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/Child.svelte b/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/Child.svelte
index 3e39d5043eff..97fae9ad7327 100644
--- a/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/Child.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/Child.svelte
@@ -1,7 +1,10 @@
 <script>
-	import { get } from './main.svelte';
+	import { get, has } from './main.svelte';
 
 	const message = get();
 </script>
 
 <h1>{message}</h1>
+{#if has()}
+	<h2>it's me</h2>
+{/if}
diff --git a/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/_config.js b/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/_config.js
index f4374c8759db..e0f3ed68645e 100644
--- a/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/_config.js
@@ -2,7 +2,7 @@ import { test } from '../../test';
 
 export default test({
 	ssrHtml: `<div></div>`,
-	html: `<div><h1>hello</h1></div>`,
+	html: `<div><h1>hello</h1><h2>it's me</h2></div>`,
 
 	test() {}
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/main.svelte b/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/main.svelte
index 3c42dbf1800e..327434aeca0d 100644
--- a/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/main.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/create-context-programmatic/main.svelte
@@ -3,9 +3,9 @@
 	import Child from './Child.svelte';
 
 	/** @type {ReturnType<typeof createContext<string>>} */
-	const [get, set] = createContext();
+	const [get, set, has] = createContext();
 
-	export { get };
+	export { get, has };
 
 	function Wrapper(Component) {
 		return (...args) => {
@@ -15,6 +15,8 @@
 	}
 </script>
 
-<div {@attach (target) => {
-	mount(Wrapper(Child), { target });
-}}></div>
+<div
+	{@attach (target) => {
+		mount(Wrapper(Child), { target });
+	}}
+></div>
diff --git a/packages/svelte/tests/runtime-runes/samples/create-context/Child.svelte b/packages/svelte/tests/runtime-runes/samples/create-context/Child.svelte
index 3e39d5043eff..97fae9ad7327 100644
--- a/packages/svelte/tests/runtime-runes/samples/create-context/Child.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/create-context/Child.svelte
@@ -1,7 +1,10 @@
 <script>
-	import { get } from './main.svelte';
+	import { get, has } from './main.svelte';
 
 	const message = get();
 </script>
 
 <h1>{message}</h1>
+{#if has()}
+	<h2>it's me</h2>
+{/if}
diff --git a/packages/svelte/tests/runtime-runes/samples/create-context/_config.js b/packages/svelte/tests/runtime-runes/samples/create-context/_config.js
index 4ae28e68bd05..4901788630fa 100644
--- a/packages/svelte/tests/runtime-runes/samples/create-context/_config.js
+++ b/packages/svelte/tests/runtime-runes/samples/create-context/_config.js
@@ -1,5 +1,5 @@
 import { test } from '../../test';
 
 export default test({
-	html: `<h1>hello</h1>`
+	html: `<h1>hello</h1><h2>it's me</h2>`
 });
diff --git a/packages/svelte/tests/runtime-runes/samples/create-context/main.svelte b/packages/svelte/tests/runtime-runes/samples/create-context/main.svelte
index 8d3c50ba5539..10b54eaa5c05 100644
--- a/packages/svelte/tests/runtime-runes/samples/create-context/main.svelte
+++ b/packages/svelte/tests/runtime-runes/samples/create-context/main.svelte
@@ -2,9 +2,9 @@
 	import { createContext } from 'svelte';
 
 	/** @type {ReturnType<typeof createContext<string>>} */
-	const [get, set] = createContext();
+	const [get, set, has] = createContext();
 
-	export { get };
+	export { get, has };
 </script>
 
 <script>

From cacace3b5696d378a2785d04478db47a291569aa Mon Sep 17 00:00:00 2001
From: soleuniverse <dev@soleuniverse.me>
Date: Sat, 27 Jun 2026 07:12:54 +0200
Subject: [PATCH 3/5] docs: update missing_context error to match new
 createContext signature

---
 packages/svelte/messages/shared-errors/errors.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/svelte/messages/shared-errors/errors.md b/packages/svelte/messages/shared-errors/errors.md
index 3ff474768ef3..2b878d195897 100644
--- a/packages/svelte/messages/shared-errors/errors.md
+++ b/packages/svelte/messages/shared-errors/errors.md
@@ -64,7 +64,7 @@ Certain lifecycle methods can only be used during component initialisation. To f
 
 > Context was not set in a parent component
 
-The [`createContext()`](svelte#createContext) utility returns a `[get, set]` pair of functions. `get` will throw an error if `set` was not used to set the context in a parent component.
+The [`createContext()`](svelte#createContext) utility returns a `[get, set, has]` triplet of functions. `get` will throw an error if `set` was not used to set the context in a parent component.
 
 ## snippet_without_render_tag
 

From 3ac8ea98bc30b80395878866e4939c34d8c6b41d Mon Sep 17 00:00:00 2001
From: soleuniverse <dev@soleuniverse.me>
Date: Sat, 27 Jun 2026 07:14:11 +0200
Subject: [PATCH 4/5] docs: update context docs page to match new createContext
 signature

---
 documentation/docs/06-runtime/02-context.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/documentation/docs/06-runtime/02-context.md b/documentation/docs/06-runtime/02-context.md
index 439272df8fac..20ebe3489301 100644
--- a/documentation/docs/06-runtime/02-context.md
+++ b/documentation/docs/06-runtime/02-context.md
@@ -4,7 +4,7 @@ title: Context
 
 Context allows components to access values owned by parent components without passing them down as props (potentially through many layers of intermediate components, known as 'prop-drilling').
 
-By creating a `[get, set]` pair of functions with `createContext`, you can set the context in a parent component and get it in a child component:
+By creating a `[get, set, has]` triplet of functions with `createContext`, you can set the context in a parent component and get it in a child component:
 
 <!-- codeblock:start {"title":"Context","selected":"context.ts"} -->
 ```svelte
@@ -51,6 +51,7 @@ interface User {
 	name: string;
 }
 
+// hasUserContext isn't needed here so it's not defined
 export const [getUserContext, setUserContext] = createContext<User>();
 ```
 <!-- codeblock:end -->

From 6d5508df230528ceaf66c8c25d1e34a794561cc4 Mon Sep 17 00:00:00 2001
From: soleuniverse <dev@soleuniverse.me>
Date: Sat, 27 Jun 2026 07:17:53 +0200
Subject: [PATCH 5/5] docs: add changeset

---
 .changeset/short-feet-admire.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/short-feet-admire.md

diff --git a/.changeset/short-feet-admire.md b/.changeset/short-feet-admire.md
new file mode 100644
index 000000000000..48062bd053ca
--- /dev/null
+++ b/.changeset/short-feet-admire.md
@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: add has function to createContext