From 222a9dd2c6cd341135c3e8c16c89774eeb06d4f8 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <tanhauhau@users.noreply.github.com>
Date: Wed, 21 Jul 2021 12:59:00 +0800
Subject: [PATCH] [feat] get all contexts (#6528)

* get all contexts

* docs

* explicit return type

* allow specifying return type through generic parameter

* Update site/content/docs/03-run-time.md

Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>
---
 site/content/docs/03-run-time.md               | 18 ++++++++++++++++++
 src/runtime/index.ts                           |  1 +
 src/runtime/internal/lifecycle.ts              |  4 ++++
 src/runtime/ssr.ts                             |  1 +
 test/runtime/samples/context-api-d/Leaf.svelte |  9 +++++++++
 .../samples/context-api-d/Nested.svelte        |  8 ++++++++
 test/runtime/samples/context-api-d/_config.js  |  7 +++++++
 test/runtime/samples/context-api-d/main.svelte |  8 ++++++++
 8 files changed, 56 insertions(+)
 create mode 100644 test/runtime/samples/context-api-d/Leaf.svelte
 create mode 100644 test/runtime/samples/context-api-d/Nested.svelte
 create mode 100644 test/runtime/samples/context-api-d/_config.js
 create mode 100644 test/runtime/samples/context-api-d/main.svelte

diff --git a/site/content/docs/03-run-time.md b/site/content/docs/03-run-time.md
index da65ac2488..d7bf3757df 100644
--- a/site/content/docs/03-run-time.md
+++ b/site/content/docs/03-run-time.md
@@ -200,6 +200,24 @@ Checks whether a given `key` has been set in the context of a parent component.
 </script>
 ```
 
+#### `getAllContexts`
+
+```js
+contexts: Map<any, any> = getAllContexts()
+```
+
+---
+
+Retrieves the whole context map that belongs to the closest parent component. Must be called during component initialisation. Useful, for example, if you programmatically create a component and want to pass the existing context to it.
+
+```sv
+<script>
+	import { getAllContexts } from 'svelte';
+
+	const contexts = getAllContexts();
+</script>
+```
+
 #### `createEventDispatcher`
 
 ```js
diff --git a/src/runtime/index.ts b/src/runtime/index.ts
index b3451ed5cb..8e12f9f0ee 100644
--- a/src/runtime/index.ts
+++ b/src/runtime/index.ts
@@ -7,6 +7,7 @@ export {
 	afterUpdate,
 	setContext,
 	getContext,
+	getAllContexts,
 	hasContext,
 	tick,
 	createEventDispatcher,
diff --git a/src/runtime/internal/lifecycle.ts b/src/runtime/internal/lifecycle.ts
index a84bcc689b..bb3df3d295 100644
--- a/src/runtime/internal/lifecycle.ts
+++ b/src/runtime/internal/lifecycle.ts
@@ -54,6 +54,10 @@ export function getContext<T>(key): T {
 	return get_current_component().$$.context.get(key);
 }
 
+export function getAllContexts<T extends Map<any, any> = Map<any, any>>(): T {
+	return get_current_component().$$.context;
+}
+
 export function hasContext(key): boolean {
 	return get_current_component().$$.context.has(key);	
 }
diff --git a/src/runtime/ssr.ts b/src/runtime/ssr.ts
index c75bb30349..69fe841e5c 100644
--- a/src/runtime/ssr.ts
+++ b/src/runtime/ssr.ts
@@ -1,6 +1,7 @@
 export {
 	setContext,
 	getContext,
+	getAllContexts,
 	hasContext,
 	tick,
 	createEventDispatcher,
diff --git a/test/runtime/samples/context-api-d/Leaf.svelte b/test/runtime/samples/context-api-d/Leaf.svelte
new file mode 100644
index 0000000000..02b6b26e00
--- /dev/null
+++ b/test/runtime/samples/context-api-d/Leaf.svelte
@@ -0,0 +1,9 @@
+<script>
+	import { getAllContexts } from 'svelte';
+
+	const context = getAllContexts();
+</script>
+
+{#each [...context.keys()] as key}
+	<div>{key}: {context.get(key)}</div>
+{/each}
diff --git a/test/runtime/samples/context-api-d/Nested.svelte b/test/runtime/samples/context-api-d/Nested.svelte
new file mode 100644
index 0000000000..e8a7e083c3
--- /dev/null
+++ b/test/runtime/samples/context-api-d/Nested.svelte
@@ -0,0 +1,8 @@
+<script>
+	import { setContext } from 'svelte';
+  setContext('a', 1);
+  setContext('b', 2);
+  setContext('c', 3);
+</script>
+
+<slot></slot>
\ No newline at end of file
diff --git a/test/runtime/samples/context-api-d/_config.js b/test/runtime/samples/context-api-d/_config.js
new file mode 100644
index 0000000000..a5b0769f8b
--- /dev/null
+++ b/test/runtime/samples/context-api-d/_config.js
@@ -0,0 +1,7 @@
+export default {
+	html: `
+		<div>a: 1</div>
+		<div>b: 2</div>
+		<div>c: 3</div>
+	`
+};
diff --git a/test/runtime/samples/context-api-d/main.svelte b/test/runtime/samples/context-api-d/main.svelte
new file mode 100644
index 0000000000..82d1021574
--- /dev/null
+++ b/test/runtime/samples/context-api-d/main.svelte
@@ -0,0 +1,8 @@
+<script>
+  import Nested from './Nested.svelte';
+  import Leaf from './Leaf.svelte';
+</script>
+
+<Nested>
+  <Leaf />
+</Nested>