fix: markdown cannot find relative image path without leading ./ (#10801)

.changeset/thirty-walls-yell.md

@@ -0,0 +1,15 @@
+---
+"astro": patch
+---
+
+Fixes an issue where images in MD required a relative specifier (e.g. `./`)
+
+Now, you can use the standard `![](relative/img.png)` syntax in MD files for images colocated in the same folder: no relative specifier required!
+
+There is no need to update your project; your existing images will still continue to work. However, you may wish to remove any relative specifiers from these MD images as they are no longer necessary:
+
+```diff
+- ![A cute dog](./dog.jpg)
++ ![A cute dog](dog.jpg)
+<!-- This dog lives in the same folder as my article! -->
+```

packages/astro/src/vite-plugin-markdown/images.ts

@@ -1,13 +1,10 @@
-export type MarkdownImagePath = { raw: string; resolved: string; safeName: string };
+export type MarkdownImagePath = { raw: string; safeName: string };
 
 export function getMarkdownCodeForImages(imagePaths: MarkdownImagePath[], html: string) {
 	return `
 			import { getImage } from "astro:assets";
 			${imagePaths
-				.map((entry) => {
-					const prefix = entry.raw.includes('/') ? '' : './';
-					return `import Astro__${entry.safeName} from ${JSON.stringify(prefix + entry.raw)};`;
-				})
+				.map((entry) => `import Astro__${entry.safeName} from ${JSON.stringify(entry.raw)};`)
 				.join('\n')}
 
 			const images = async function(html) {

packages/astro/src/vite-plugin-markdown/index.ts

@@ -1,5 +1,4 @@
 import fs from 'node:fs';
-import path from 'node:path';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 import {
 	InvalidAstroDataError,
@@ -43,6 +42,13 @@ export default function markdown({ settings, logger }: AstroPluginOptions): Plug
 		buildEnd() {
 			processor = undefined;
 		},
+		async resolveId(source, importer, options) {
+			if (importer?.endsWith('.md') && source[0] !== '/') {
+				let resolved = await this.resolve(source, importer, options);
+				if (!resolved) resolved = await this.resolve('./' + source, importer, options);
+				return resolved;
+			}
+		},
 		// Why not the "transform" hook instead of "load" + readFile?
 		// A: Vite transforms all "import.meta.env" references to their values before
 		// passing to the transform hook. This lets us get the truly raw value
@@ -85,8 +91,6 @@ export default function markdown({ settings, logger }: AstroPluginOptions): Plug
 				for (const imagePath of rawImagePaths.values()) {
 					imagePaths.push({
 						raw: imagePath,
-						resolved:
-							(await this.resolve(imagePath, id))?.id ?? path.join(path.dirname(id), imagePath),
 						safeName: shorthash(imagePath),
 					});
 				}

packages/astro/test/fixtures/markdown/src/pages/images.md

@@ -0,0 +1,2 @@
+![houston image](houston.png)
+![nested houston image](relative/houston.png)

packages/astro/test/markdown.test.js

@@ -65,7 +65,6 @@ describe('Markdown tests', () => {
 		it('Can load a realworld markdown page with Astro', async () => {
 			const html = await fixture.readFile('/realworld/index.html');
 			const $ = cheerio.load(html);
-
 			assert.equal($('pre').length, 7);
 		});
 
@@ -73,5 +72,12 @@ describe('Markdown tests', () => {
 			const html = await fixture.readFile('/entities/index.html');
 			assert.match(html, /<i>This should NOT be italic<\/i>/);
 		});
+
+		it('Resolves the image paths correctly', async () => {
+			const html = await fixture.readFile('/images/index.html');
+			const $ = cheerio.load(html);
+			assert.equal($('img').first().attr('src').includes('.webp'), true);
+			assert.equal($('img').first().next().attr('src').includes('.webp'), true);
+		});
 	});
 });