fix: throw an error if image cannot be resolved (#11346)

Author: benmccann

.changeset/polite-rice-burn.md

@@ -0,0 +1,5 @@
+---
+"@sveltejs/enhanced-img": patch
+---
+
+fix: throw an error if image cannot be resolved

packages/enhanced-img/src/index.js

@@ -25,12 +25,15 @@ function image_plugin(imagetools_plugin) {
 	/**
 	 * @type {{
 	 *   plugin_context: import('vite').Rollup.PluginContext
+	 *   vite_config: import('vite').ResolvedConfig
 	 *   imagetools_plugin: import('vite').Plugin
 	 * }}
 	 */
 	const opts = {
 		// @ts-expect-error populated when build starts so we cheat on type
 		plugin_context: undefined,
+		// @ts-expect-error populated when build starts so we cheat on type
+		vite_config: undefined,
 		imagetools_plugin
 	};
 	const preprocessor = image(opts);
@@ -40,6 +43,9 @@ function image_plugin(imagetools_plugin) {
 		api: {
 			sveltePreprocess: preprocessor
 		},
+		configResolved(config) {
+			opts.vite_config = config;
+		},
 		buildStart() {
 			opts.plugin_context = this;
 		}

packages/enhanced-img/src/preprocessor.js

@@ -1,3 +1,6 @@
+import { existsSync } from 'node:fs';
+import * as path from 'node:path';
+
 import MagicString from 'magic-string';
 import { asyncWalk } from 'estree-walker';
 import { parse } from 'svelte-parse-markup';
@@ -10,6 +13,7 @@ const OPTIMIZABLE = /^[^?]+\.(avif|heif|gif|jpeg|jpg|png|tiff|webp)(\?.*)?$/;
 /**
  * @param {{
  *   plugin_context: import('vite').Rollup.PluginContext
+ *   vite_config: import('vite').ResolvedConfig
  *   imagetools_plugin: import('vite').Plugin
  * }} opts
  * @returns {import('svelte/types/compiler/preprocess').PreprocessorGroup}
@@ -72,7 +76,15 @@ export function image(opts) {
 						// need any logic blocks
 						image = await resolve(opts, url, filename);
 						if (!image) {
-							return;
+							const file_path = url.substring(0, url.indexOf('?'));
+							if (existsSync(path.resolve(opts.vite_config.publicDir, file_path))) {
+								throw new Error(
+									`Could not locate ${file_path}. Please move it to be located relative to the page in the routes directory or reference it beginning with /static/. See https://vitejs.dev/guide/assets for more details on referencing assets.`
+								);
+							}
+							throw new Error(
+								`Could not locate ${file_path}. See https://vitejs.dev/guide/assets for more details on referencing assets.`
+							);
 						}
 						images.set(url, image);
 					}