Expose inferRemoteSize function (#11098)

* feat: expose and rename `inferSize`

* feat: separate `ISize` type

* feat: reformat function to use `ImageMetadata`

* nit(assets): re-use image-metadata code for remote images

* chore: changeset

* chore: changeset

* feat(assets): Export from `astro:assets`

* fix: proper errors

* fix: dont export from astro/assets

* fix: ests

* Update .changeset/large-geese-play.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* fix: ests

* Update .changeset/large-geese-play.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

---------

Co-authored-by: Erika <3019731+Princesseuh@users.noreply.github.com>
Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

.changeset/large-geese-play.md

@@ -0,0 +1,20 @@
+---
+"astro": minor
+---
+
+Adds a new `inferRemoteSize()` function that can be used to infer the dimensions of a remote image.
+
+Previously, the ability to infer these values was only available by adding the [`inferSize`] attribute to the `<Image>` and `<Picture>` components or `getImage()`. Now, you can also access this data outside of these components. 
+ 
+This is useful for when you need to know the dimensions of an image for styling purposes or to calculate different densities for responsive images.
+
+```astro
+---
+import { inferRemoteSize, Image } from 'astro:assets';
+
+const imageUrl = 'https://...';
+const { width, height } = await inferRemoteSize(imageUrl);
+---
+
+<Image src={imageUrl} width={width / 2} height={height} densities={[1.5, 2]}  />
+```

packages/astro/client.d.ts

@@ -54,6 +54,7 @@ declare module 'astro:assets' {
 		) => Promise<import('./dist/assets/types.js').GetImageResult>;
 		imageConfig: import('./dist/@types/astro.js').AstroConfig['image'];
 		getConfiguredImageService: typeof import('./dist/assets/index.js').getConfiguredImageService;
+		inferRemoteSize: typeof import('./dist/assets/utils/index.js').inferRemoteSize;
 		Image: typeof import('./components/Image.astro').default;
 		Picture: typeof import('./components/Picture.astro').default;
 	};

packages/astro/package.json

@@ -63,6 +63,7 @@
     "./actions/runtime/*": "./dist/actions/runtime/*",
     "./assets": "./dist/assets/index.js",
     "./assets/utils": "./dist/assets/utils/index.js",
+    "./assets/utils/inferRemoteSize.js": "./dist/assets/utils/remoteProbe.js",
     "./assets/endpoint/*": "./dist/assets/endpoint/*.js",
     "./assets/services/sharp": "./dist/assets/services/sharp.js",
     "./assets/services/squoosh": "./dist/assets/services/squoosh.js",

packages/astro/src/assets/internal.ts

@@ -10,7 +10,7 @@ import {
 	isImageMetadata,
 } from './types.js';
 import { isESMImportedImage, isRemoteImage, resolveSrc } from './utils/imageKind.js';
-import { probe } from './utils/remoteProbe.js';
+import { inferRemoteSize } from './utils/remoteProbe.js';
 
 export async function getConfiguredImageService(): Promise<ImageService> {
 	if (!globalThis?.astroAsset?.imageService) {
@@ -66,17 +66,10 @@ export async function getImage(
 
 	// Infer size for remote images if inferSize is true
 	if (options.inferSize && isRemoteImage(resolvedOptions.src)) {
-		try {
-			const result = await probe(resolvedOptions.src); // Directly probe the image URL
-			resolvedOptions.width ??= result.width;
-			resolvedOptions.height ??= result.height;
-			delete resolvedOptions.inferSize; // Delete so it doesn't end up in the attributes
-		} catch {
-			throw new AstroError({
-				...AstroErrorData.FailedToFetchRemoteImageDimensions,
-				message: AstroErrorData.FailedToFetchRemoteImageDimensions.message(resolvedOptions.src),
-			});
-		}
+		const result = await inferRemoteSize(resolvedOptions.src); // Directly probe the image URL
+		resolvedOptions.width ??= result.width;
+		resolvedOptions.height ??= result.height;
+		delete resolvedOptions.inferSize; // Delete so it doesn't end up in the attributes
 	}
 
 	const originalFilePath = isESMImportedImage(resolvedOptions.src)

packages/astro/src/assets/utils/index.ts

@@ -1,4 +1,4 @@
-export { emitESMImage } from './emitAsset.js';
+export { emitESMImage } from './node/emitAsset.js';
 export { isESMImportedImage, isRemoteImage } from './imageKind.js';
 export { imageMetadata } from './metadata.js';
 export { getOrigQueryParams } from './queryParams.js';
@@ -12,3 +12,4 @@ export {
 	type RemotePattern,
 } from './remotePattern.js';
 export { hashTransform, propsToFilename } from './transformToPath.js';
+export { inferRemoteSize } from './remoteProbe.js';

packages/astro/src/assets/utils/node/emitAsset.ts

@@ -2,9 +2,9 @@ import fs from 'node:fs/promises';
 import path from 'node:path';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 import type * as vite from 'vite';
-import { prependForwardSlash, slash } from '../../core/path.js';
-import type { ImageMetadata } from '../types.js';
-import { imageMetadata } from './metadata.js';
+import { prependForwardSlash, slash } from '../../../core/path.js';
+import type { ImageMetadata } from '../../types.js';
+import { imageMetadata } from '../metadata.js';
 
 type FileEmitter = vite.Rollup.EmitFile;
 

packages/astro/src/assets/utils/remoteProbe.ts

@@ -1,11 +1,15 @@
-import { lookup } from './vendor/image-size/lookup.js';
-import type { ISize } from './vendor/image-size/types/interface.ts';
+import { AstroError, AstroErrorData } from '../../core/errors/index.js';
+import type { ImageMetadata } from '../types.js';
+import { imageMetadata } from './metadata.js';
 
-export async function probe(url: string): Promise<ISize> {
+export async function inferRemoteSize(url: string): Promise<Omit<ImageMetadata, 'src' | 'fsPath'>> {
 	// Start fetching the image
 	const response = await fetch(url);
 	if (!response.body || !response.ok) {
-		throw new Error('Failed to fetch image');
+		throw new AstroError({
+			...AstroErrorData.FailedToFetchRemoteImageDimensions,
+			message: AstroErrorData.FailedToFetchRemoteImageDimensions.message(url),
+		});
 	}
 
 	const reader = response.body.getReader();
@@ -31,17 +35,22 @@ export async function probe(url: string): Promise<ISize> {
 
 			try {
 				// Attempt to determine the size with each new chunk
-				const dimensions = lookup(accumulatedChunks);
+				const dimensions = await imageMetadata(accumulatedChunks, url);
+
 				if (dimensions) {
 					await reader.cancel(); // stop stream as we have size now
+
 					return dimensions;
 				}
 			} catch (error) {
-				// This catch block is specifically for `sizeOf` failures,
+				// This catch block is specifically for `imageMetadata` errors
 				// which might occur if the accumulated data isn't yet sufficient.
 			}
 		}
 	}
 
-	throw new Error('Failed to parse the size');
+	throw new AstroError({
+		...AstroErrorData.NoImageMetadata,
+		message: AstroErrorData.NoImageMetadata.message(url),
+	});
 }

packages/astro/src/assets/vite-plugin-assets.ts

@@ -14,7 +14,7 @@ import {
 } from '../core/path.js';
 import { isServerLikeOutput } from '../core/util.js';
 import { VALID_INPUT_FORMATS, VIRTUAL_MODULE_ID, VIRTUAL_SERVICE_ID } from './consts.js';
-import { emitESMImage } from './utils/emitAsset.js';
+import { emitESMImage } from './utils/node/emitAsset.js';
 import { getAssetsPrefix } from './utils/getAssetsPrefix.js';
 import { isESMImportedImage } from './utils/imageKind.js';
 import { getProxyCode } from './utils/proxy.js';
@@ -133,6 +133,7 @@ export default function assets({
 					import { getImage as getImageInternal } from "astro/assets";
 					export { default as Image } from "astro/components/Image.astro";
 					export { default as Picture } from "astro/components/Picture.astro";
+					export { inferRemoteSize } from "astro/assets/utils/inferRemoteSize.js";
 
 					export const imageConfig = ${JSON.stringify(settings.config.image)};
 					// This is used by the @astrojs/node integration to locate images.

packages/astro/src/content/runtime-assets.ts

@@ -1,7 +1,7 @@
 import type { PluginContext } from 'rollup';
 import { z } from 'zod';
 import type { ImageMetadata, OmitBrand } from '../assets/types.js';
-import { emitESMImage } from '../assets/utils/emitAsset.js';
+import { emitESMImage } from '../assets/utils/node/emitAsset.js';
 
 export function createImage(
 	pluginContext: PluginContext,

packages/astro/test/core-image-infersize.test.js

@@ -70,6 +70,11 @@ describe('astro:image:infersize', () => {
 					true
 				);
 			});
+
+			it('direct function call work', async () => {
+				let $dimensions = $('#direct');
+				assert.equal($dimensions.text().trim(), '64x64');
+			});
 		});
 	});
 });

packages/astro/test/fixtures/core-image-infersize/src/pages/index.astro

@@ -1,6 +1,9 @@
 ---
 // https://avatars.githubusercontent.com/u/622227?s=64 is a .jpeg
-import { Image, Picture, getImage } from 'astro:assets';
+import { Image, Picture, getImage, inferRemoteSize } from 'astro:assets';
+
+const { width, height } = await inferRemoteSize('https://avatars.githubusercontent.com/u/622227?s=64');
+
 const remoteImg = await getImage({
 	src: 'https://avatars.githubusercontent.com/u/622227?s=64',
 	inferSize: true,
@@ -10,3 +13,7 @@ const remoteImg = await getImage({
 <Image src="https://avatars.githubusercontent.com/u/622227?s=64," inferSize={true} , alt="" />
 <Picture src="https://avatars.githubusercontent.com/u/622227?s=64," inferSize={true} , alt="" />
 <img src={remoteImg.src} {...remoteImg.attributes} id="getImage" />
+
+<div id="direct">
+	{width}x{height}
+</div>