fix: basic mime type handling for prerendered pages in preview (#10851)

Author: benmccann

.changeset/brave-parrots-sleep.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: basic mime type handling for prerendered pages in preview

.changeset/clean-garlics-deny.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+chore: use just a single library (mrmime) for mime type handling

packages/kit/package.json

@@ -18,7 +18,7 @@
 		"esm-env": "^1.0.0",
 		"kleur": "^4.1.5",
 		"magic-string": "^0.30.0",
-		"mime": "^3.0.0",
+		"mrmime": "^1.0.1",
 		"sade": "^1.8.1",
 		"set-cookie-parser": "^2.6.0",
 		"sirv": "^2.0.2",
@@ -28,7 +28,6 @@
 	"devDependencies": {
 		"@playwright/test": "1.30.0",
 		"@types/connect": "^3.4.35",
-		"@types/mime": "^3.0.1",
 		"@types/node": "^16.18.6",
 		"@types/sade": "^1.7.4",
 		"@types/set-cookie-parser": "^2.4.2",

packages/kit/src/core/sync/create_manifest_data/index.js

@@ -1,7 +1,7 @@
 import fs from 'node:fs';
 import path from 'node:path';
 import colors from 'kleur';
-import mime from 'mime';
+import { lookup } from 'mrmime';
 import { list_files, runtime_directory } from '../../utils.js';
 import { posixify } from '../../../utils/filesystem.js';
 import { parse_route_id } from '../../../utils/routing.js';
@@ -48,7 +48,7 @@ export function create_assets(config) {
 	return list_files(config.kit.files.assets).map((file) => ({
 		file,
 		size: fs.statSync(path.resolve(config.kit.files.assets, file)).size,
-		type: mime.getType(file)
+		type: lookup(file) || null
 	}));
 }
 

packages/kit/src/exports/vite/preview/index.js

@@ -1,6 +1,7 @@
 import fs from 'node:fs';
 import { join } from 'node:path';
 import { pathToFileURL } from 'node:url';
+import { lookup } from 'mrmime';
 import sirv from 'sirv';
 import { loadEnv, normalizePath } from 'vite';
 import { getRequest, setResponse } from '../../../exports/node/index.js';
@@ -141,7 +142,7 @@ export async function preview(vite, vite_config, svelte_config) {
 
 				if (prerendered) {
 					res.writeHead(200, {
-						'content-type': 'text/html',
+						'content-type': lookup(pathname) || 'text/html',
 						etag
 					});