Add support for SVG images to `@astrojs/image` (#6118)

* @astrojs/image: add support for SVG images

* @astrojs/image: add tests for SVG images

* @astrojs/image: update README.md with SVG format info

* Add minor changeset for @astrojs/image

12 files changed, 122 insertions, 7 deletions

diff --git a/.changeset/little-carrots-add.md b/.changeset/little-carrots-add.md
new file mode 100644
index 000000000..433635158
--- /dev/null
+++ b/.changeset/little-carrots-add.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/image': minor
+---
+
+Add support for SVG images
diff --git a/packages/integrations/image/README.md b/packages/integrations/image/README.md
index 1cb0d5d4c..d1cc22f2c 100644
--- a/packages/integrations/image/README.md
+++ b/packages/integrations/image/README.md
@@ -169,13 +169,16 @@ Set to an empty string (`alt=""`) if the image is not a key part of the content
 
 <p>
 
-**Type:** `'avif' | 'jpeg' | 'png' | 'webp'`<br>
+**Type:** `'avif' | 'jpeg' | 'jpg' | 'png' | 'svg' | 'webp'`<br>
 **Default:** `undefined`
 </p>
 
 The output format to be used in the optimized image. The original image format will be used if `format` is not provided.
 
 This property is required for remote images when using the default image transformer Squoosh, this is because the original format cannot be inferred.
+
+> When using the `svg` format, the original image must be in SVG format already (raster images cannot be converted to vector images). The SVG image itself won't be transformed but the final `<img />` element will get the optimization attributes.
+
 #### quality
 
 <p>
diff --git a/packages/integrations/image/client.d.ts b/packages/integrations/image/client.d.ts
index cafec4184..71842742a 100644
--- a/packages/integrations/image/client.d.ts
+++ b/packages/integrations/image/client.d.ts
@@ -1,6 +1,16 @@
 /// <reference types="astro/client-base" />
 
-type InputFormat = 'avif' | 'gif' | 'heic' | 'heif' | 'jpeg' | 'jpg' | 'png' | 'tiff' | 'webp';
+type InputFormat =
+	| 'avif'
+	| 'gif'
+	| 'heic'
+	| 'heif'
+	| 'jpeg'
+	| 'jpg'
+	| 'png'
+	| 'tiff'
+	| 'webp'
+	| 'svg';
 
 interface ImageMetadata {
 	src: string;
@@ -46,3 +56,7 @@ declare module '*.webp' {
 	const metadata: ImageMetadata;
 	export default metadata;
 }
+declare module '*.svg' {
+	const metadata: ImageMetadata;
+	export default metadata;
+}
diff --git a/packages/integrations/image/src/loaders/index.ts b/packages/integrations/image/src/loaders/index.ts
index 280fb37c2..225e98cee 100644
--- a/packages/integrations/image/src/loaders/index.ts
+++ b/packages/integrations/image/src/loaders/index.ts
@@ -10,10 +10,11 @@ export type InputFormat =
 	| 'png'
 	| 'tiff'
 	| 'webp'
-	| 'gif';
+	| 'gif'
+	| 'svg';
 
 export type OutputFormatSupportsAlpha = 'avif' | 'png' | 'webp';
-export type OutputFormat = OutputFormatSupportsAlpha | 'jpeg' | 'jpg';
+export type OutputFormat = OutputFormatSupportsAlpha | 'jpeg' | 'jpg' | 'svg';
 
 export type ColorDefinition =
 	| NamedColor
@@ -49,7 +50,7 @@ export type CropPosition =
 	| 'attention';
 
 export function isOutputFormat(value: string): value is OutputFormat {
-	return ['avif', 'jpeg', 'jpg', 'png', 'webp'].includes(value);
+	return ['avif', 'jpeg', 'jpg', 'png', 'webp', 'svg'].includes(value);
 }
 
 export function isOutputFormatSupportsAlpha(value: string): value is OutputFormatSupportsAlpha {
diff --git a/packages/integrations/image/src/loaders/sharp.ts b/packages/integrations/image/src/loaders/sharp.ts
index 55ea28645..517224289 100644
--- a/packages/integrations/image/src/loaders/sharp.ts
+++ b/packages/integrations/image/src/loaders/sharp.ts
@@ -5,6 +5,14 @@ import type { OutputFormat, TransformOptions } from './index.js';
 
 class SharpService extends BaseSSRService {
 	async transform(inputBuffer: Buffer, transform: TransformOptions) {
+		if (transform.format === 'svg') {
+			// sharp can't output SVG so we return the input image
+			return {
+				data: inputBuffer,
+				format: transform.format,
+			};
+		}
+
 		const sharpImage = sharp(inputBuffer, { failOnError: false, pages: -1 });
 
 		// always call rotate to adjust for EXIF data orientation
diff --git a/packages/integrations/image/src/loaders/squoosh.ts b/packages/integrations/image/src/loaders/squoosh.ts
index 5d71cdb7f..a5be16adb 100644
--- a/packages/integrations/image/src/loaders/squoosh.ts
+++ b/packages/integrations/image/src/loaders/squoosh.ts
@@ -82,6 +82,14 @@ class SquooshService extends BaseSSRService {
 	}
 
 	async transform(inputBuffer: Buffer, transform: TransformOptions) {
+		if (transform.format === 'svg') {
+			// squoosh can't output SVG so we return the input image
+			return {
+				data: inputBuffer,
+				format: transform.format,
+			};
+		}
+
 		const operations: Operation[] = [];
 
 		if (!isRemoteImage(transform.src)) {
diff --git a/packages/integrations/image/src/vite-plugin-astro-image.ts b/packages/integrations/image/src/vite-plugin-astro-image.ts
index 3eee310e8..b721578a5 100644
--- a/packages/integrations/image/src/vite-plugin-astro-image.ts
+++ b/packages/integrations/image/src/vite-plugin-astro-image.ts
@@ -1,5 +1,6 @@
 import type { AstroConfig } from 'astro';
 import MagicString from 'magic-string';
+import mime from 'mime';
 import fs from 'node:fs/promises';
 import { basename, extname } from 'node:path';
 import { Readable } from 'node:stream';
@@ -18,7 +19,7 @@ export interface ImageMetadata {
 
 export function createPlugin(config: AstroConfig, options: Required<IntegrationOptions>): Plugin {
 	const filter = (id: string) =>
-		/^(?!\/_image?).*.(heic|heif|avif|jpeg|jpg|png|tiff|webp|gif)$/.test(id);
+		/^(?!\/_image?).*.(heic|heif|avif|jpeg|jpg|png|tiff|webp|gif|svg)$/.test(id);
 
 	const virtualModuleId = 'virtual:image-loader';
 
@@ -97,7 +98,7 @@ export function createPlugin(config: AstroConfig, options: Required<IntegrationO
 						format = result.format;
 					}
 
-					res.setHeader('Content-Type', `image/${format}`);
+					res.setHeader('Content-Type', mime.getType(format) || '');
 					res.setHeader('Cache-Control', 'max-age=360000');
 
 					const stream = Readable.from(data);
diff --git a/packages/integrations/image/test/fixtures/basic-image/src/assets/logo.svg b/packages/integrations/image/test/fixtures/basic-image/src/assets/logo.svg
new file mode 100644
index 000000000..a1388d931
--- /dev/null
+++ b/packages/integrations/image/test/fixtures/basic-image/src/assets/logo.svg
@@ -0,0 +1,22 @@
+<svg width="192" height="256" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <path fill-rule="evenodd" clip-rule="evenodd"
+    d="M131.008 18.929c1.944 2.413 2.935 5.67 4.917 12.181l43.309 142.27a180.277 180.277 0 00-51.778-17.53L99.258 60.56a3.67 3.67 0 00-7.042.01l-27.857 95.232a180.225 180.225 0 00-52.01 17.557l43.52-142.281c1.99-6.502 2.983-9.752 4.927-12.16a15.999 15.999 0 016.484-4.798c2.872-1.154 6.271-1.154 13.07-1.154h31.085c6.807 0 10.211 0 13.086 1.157a16.004 16.004 0 016.487 4.806z"
+    fill="url(#paint0_linear)" />
+  <path fill-rule="evenodd" clip-rule="evenodd"
+    d="M136.19 180.151c-7.139 6.105-21.39 10.268-37.804 10.268-20.147 0-37.033-6.272-41.513-14.707-1.602 4.835-1.961 10.367-1.961 13.902 0 0-1.056 17.355 11.015 29.426 0-6.268 5.081-11.349 11.35-11.349 10.742 0 10.73 9.373 10.72 16.977v.679c0 11.542 7.054 21.436 17.086 25.606a23.27 23.27 0 01-2.339-10.2c0-11.008 6.463-15.107 13.974-19.87 5.976-3.79 12.616-8.001 17.192-16.449a31.024 31.024 0 003.743-14.82c0-3.299-.513-6.479-1.463-9.463z"
+    fill="#FF5D01" />
+  <path fill-rule="evenodd" clip-rule="evenodd"
+    d="M136.19 180.151c-7.139 6.105-21.39 10.268-37.804 10.268-20.147 0-37.033-6.272-41.513-14.707-1.602 4.835-1.961 10.367-1.961 13.902 0 0-1.056 17.355 11.015 29.426 0-6.268 5.081-11.349 11.35-11.349 10.742 0 10.73 9.373 10.72 16.977v.679c0 11.542 7.054 21.436 17.086 25.606a23.27 23.27 0 01-2.339-10.2c0-11.008 6.463-15.107 13.974-19.87 5.976-3.79 12.616-8.001 17.192-16.449a31.024 31.024 0 003.743-14.82c0-3.299-.513-6.479-1.463-9.463z"
+    fill="url(#paint1_linear)" />
+  <defs>
+    <linearGradient id="paint0_linear" x1="144.599" y1="5.423" x2="95.791" y2="173.38" gradientUnits="userSpaceOnUse">
+      <stop stop-color="#000014" />
+      <stop offset="1" stop-color="#150426" />
+    </linearGradient>
+    <linearGradient id="paint1_linear" x1="168.336" y1="130.49" x2="126.065" y2="218.982"
+      gradientUnits="userSpaceOnUse">
+      <stop stop-color="#FF1639" />
+      <stop offset="1" stop-color="#FF1639" stop-opacity="0" />
+    </linearGradient>
+  </defs>
+</svg>
diff --git a/packages/integrations/image/test/fixtures/basic-image/src/pages/index.astro b/packages/integrations/image/test/fixtures/basic-image/src/pages/index.astro
index ba492576c..ed1d79db6 100644
--- a/packages/integrations/image/test/fixtures/basic-image/src/pages/index.astro
+++ b/packages/integrations/image/test/fixtures/basic-image/src/pages/index.astro
@@ -1,5 +1,6 @@
 ---
 import socialJpg from '../assets/social.jpg';
+import logoSvg from '../assets/logo.svg';
 import introJpg from '../assets/blog/introducing astro.jpg';
 import outsideSrc from '../../social.png';
 import { Image } from '@astrojs/image/components';
@@ -21,6 +22,8 @@ const publicImage = new URL('./hero.jpg', Astro.url);
 		<br />
 		<Image id="outside-src" src={outsideSrc} alt="outside-src" />
 		<br />
+		<Image id="logo-svg" src={logoSvg} alt="logo-svg" />
+		<br />
 		<Image id="google" src="https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png" width={544} height={184} format="webp" alt="Google" />
 		<br />
 		<Image id="inline" src={import('../assets/social.jpg')} width={506} alt="inline" />
diff --git a/packages/integrations/image/test/image-ssg.test.js b/packages/integrations/image/test/image-ssg.test.js
index 5bc1c1e0d..12b3ffea9 100644
--- a/packages/integrations/image/test/image-ssg.test.js
+++ b/packages/integrations/image/test/image-ssg.test.js
@@ -53,6 +53,12 @@ describe('SSG images - dev', function () {
 			contentType: 'image/png',
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			url: toAstroImage('src/assets/logo.svg'),
+			query: { f: 'svg', w: '192', h: '256' },
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			url: toAstroImage('src/assets/social.jpg'),
@@ -158,6 +164,12 @@ describe('SSG images with subpath - dev', function () {
 			contentType: 'image/png',
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			url: toAstroImage('src/assets/logo.svg'),
+			query: { f: 'svg', w: '192', h: '256' },
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			url: toAstroImage('src/assets/social.jpg'),
@@ -264,6 +276,12 @@ describe('SSG images - build', function () {
 			size: { type: 'png', width: 2024, height: 1012 },
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			regex: /^\/_astro\/logo.\w{8}_\w{4,10}.svg/,
+			size: { width: 192, height: 256, type: 'svg' },
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			regex: /^\/_astro\/social.\w{8}_\w{4,10}.jpg/,
@@ -352,6 +370,12 @@ describe('SSG images with subpath - build', function () {
 			size: { type: 'png', width: 2024, height: 1012 },
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			regex: /^\/docs\/_astro\/logo.\w{8}_\w{4,10}.svg/,
+			size: { width: 192, height: 256, type: 'svg' },
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			regex: /^\/docs\/_astro\/social.\w{8}_\w{4,10}.jpg/,
diff --git a/packages/integrations/image/test/image-ssr-build.test.js b/packages/integrations/image/test/image-ssr-build.test.js
index 4b985c0ad..f85373c27 100644
--- a/packages/integrations/image/test/image-ssr-build.test.js
+++ b/packages/integrations/image/test/image-ssr-build.test.js
@@ -29,6 +29,12 @@ describe('SSR images - build', async function () {
 			query: { f: 'webp', w: '768', h: '414', href: /^\/_astro\/introducing astro.\w{8}.jpg/ },
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			url: '/_image',
+			query: { f: 'svg', w: '192', h: '256', href: /^\/_astro\/logo.\w{8}.svg/ },
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			url: '/_image',
@@ -145,6 +151,12 @@ describe('SSR images with subpath - build', function () {
 			},
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			url: '/_image',
+			query: { f: 'svg', w: '192', h: '256', href: /^\/docs\/_astro\/logo.\w{8}.svg/ },
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			url: '/_image',
diff --git a/packages/integrations/image/test/image-ssr-dev.test.js b/packages/integrations/image/test/image-ssr-dev.test.js
index fbaa6f965..186100b12 100644
--- a/packages/integrations/image/test/image-ssr-dev.test.js
+++ b/packages/integrations/image/test/image-ssr-dev.test.js
@@ -60,6 +60,13 @@ describe('SSR images - dev', function () {
 			contentType: 'image/png',
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			url: toAstroImage('src/assets/logo.svg'),
+			query: { f: 'svg', w: '192', h: '256' },
+			contentType: 'image/svg+xml',
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			url: toAstroImage('src/assets/social.jpg'),
@@ -182,6 +189,13 @@ describe('SSR images with subpath - dev', function () {
 			contentType: 'image/png',
 		},
 		{
+			title: 'SVG image',
+			id: '#logo-svg',
+			url: toAstroImage('src/assets/logo.svg'),
+			query: { f: 'svg', w: '192', h: '256' },
+			contentType: 'image/svg+xml',
+		},
+		{
 			title: 'Inline imports',
 			id: '#inline',
 			url: toAstroImage('src/assets/social.jpg'),