make manifest.mimeTypes part of the public API (#4302)

* make manifest.mime part of the public API

* change mime to mimeTypes

* update changeset

.changeset/early-pants-unite.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Make `manifest.mimeTypes` part of the public API

packages/kit/src/core/dev/plugin.js

@@ -49,8 +49,8 @@ export async function create_plugin(config, cwd) {
 				manifest = {
 					appDir: config.kit.appDir,
 					assets: new Set(manifest_data.assets.map((asset) => asset.file)),
+					mimeTypes: get_mime_lookup(manifest_data),
 					_: {
-						mime: get_mime_lookup(manifest_data),
 						entry: {
 							file: `/@fs${runtime}/client/start.js`,
 							css: [],

packages/kit/src/core/generate_manifest/index.js

@@ -58,8 +58,8 @@ export function generate_manifest({ build_data, relative_path, routes, format =
 	return `{
 		appDir: ${s(build_data.app_dir)},
 		assets: new Set(${s(assets)}),
+		mimeTypes: ${s(get_mime_lookup(build_data.manifest_data))},
 		_: {
-			mime: ${s(get_mime_lookup(build_data.manifest_data))},
 			entry: ${s(build_data.client.entry)},
 			nodes: [
 				${Array.from(bundled_nodes.values()).map(node => importer(node.path)).join(',\n\t\t\t\t')}

packages/kit/src/runtime/server/page/load_node.js

@@ -155,7 +155,7 @@ export async function load_node({
 
 					if (options.read) {
 						const type = is_asset
-							? options.manifest._.mime[filename.slice(filename.lastIndexOf('.'))]
+							? options.manifest.mimeTypes[filename.slice(filename.lastIndexOf('.'))]
 							: 'text/html';
 
 						response = new Response(options.read(file), {

packages/kit/types/index.d.ts

@@ -241,9 +241,10 @@ export class Server {
 export interface SSRManifest {
 	appDir: string;
 	assets: Set<string>;
+	mimeTypes: Record<string, string>;
+
 	/** private fields */
 	_: {
-		mime: Record<string, string>;
 		entry: {
 			file: string;
 			js: string[];