support passing context into ssr component api

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

@@ -1082,3 +1082,22 @@ const { head, html, css } = App.render({
 	answer: 42
 });
 ```
+
+You can call the `.render()` with the following parameters:
+
+| option | default | description |
+| --- | --- | --- |
+| `props` | `{}` | An object of properties to supply to the component
+| `slots` | `{}` | A object of slots to supply to the component
+| `context` | `new Map()` | A `Map` of context key-value pairs to supply to the component
+
+```js
+const { head, html, css } = App.render(
+	// props
+	{ answer: 42 },
+	// slots
+	{ 'slot-a': (lets) => 'hello world' },
+	// contexts
+	new Map([['context-key', 'context-value']]),
+);
+```

src/runtime/internal/ssr.ts

@@ -74,12 +74,12 @@ export function debug(file, line, column, values) {
 let on_destroy;
 
 export function create_ssr_component(fn) {
-	function $$render(result, props, bindings, slots) {
+	function $$render(result, props, bindings, slots, context) {
 		const parent_component = current_component;
 
 		const $$ = {
 			on_destroy,
-			context: new Map(parent_component ? parent_component.$$.context : []),
+			context: new Map(parent_component ? parent_component.$$.context : context || []),
 
 			// these will be immediately discarded
 			on_mount: [],
@@ -97,7 +97,7 @@ export function create_ssr_component(fn) {
 	}
 
 	return {
-		render: (props = {}, options = {}) => {
+		render: (props = {}, slots = {}, context = new Map()) => {
 			on_destroy = [];
 
 			const result: {
@@ -109,7 +109,7 @@ export function create_ssr_component(fn) {
 				}>;
 			} = { title: '', head: '', css: new Set() };
 
-			const html = $$render(result, props, {}, options);
+			const html = $$render(result, props, {}, slots, context);
 
 			run_all(on_destroy);
 

test/runtime/samples/constructor-pass-context/_config.js

@@ -18,5 +18,15 @@ export default {
 		assert.deepEqual(called, ['hello world']);
 
 		component.$destroy();
+	},
+	test_ssr({ assert }) {
+		const Component = require('./Component.svelte').default;
+
+		const called = [];
+		const { html } = Component.render(undefined, undefined, new Map([
+			['key', 'svelte'],
+			['fn', (value) => called.push(value)]
+		]));
+		assert.htmlEqual(html, '<div>svelte</div><button></button>');
 	}
 };