feat(image): Export more types and utilities for users to use (#6739)

13 files changed, 57 insertions, 38 deletions

diff --git a/.changeset/unlucky-emus-learn.md b/.changeset/unlucky-emus-learn.md
new file mode 100644
index 000000000..2fdac383a
--- /dev/null
+++ b/.changeset/unlucky-emus-learn.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Added more types and utilities exports related to `astro:assets` to help building custom image components and image services
diff --git a/packages/astro/src/@types/astro.ts b/packages/astro/src/@types/astro.ts
index 0064994d8..e9ac3bc23 100644
--- a/packages/astro/src/@types/astro.ts
+++ b/packages/astro/src/@types/astro.ts
@@ -30,8 +30,20 @@ export type {
 	RemarkPlugins,
 	ShikiConfig,
 } from '@astrojs/markdown-remark';
-export type { ExternalImageService, LocalImageService } from '../assets/services/service';
-export type { ImageMetadata, ImageTransform } from '../assets/types';
+export type {
+	ExternalImageService,
+	ImageService,
+	LocalImageService,
+} from '../assets/services/service';
+export type {
+	GetImageResult,
+	ImageInputFormat,
+	ImageMetadata,
+	ImageOutputFormat,
+	ImageQuality,
+	ImageQualityPreset,
+	ImageTransform,
+} from '../assets/types';
 export type { SSRManifest } from '../core/app/types';
 export type { AstroCookies } from '../core/cookies';
 
diff --git a/packages/astro/src/assets/index.ts b/packages/astro/src/assets/index.ts
index 04940ac17..6b792fa97 100644
--- a/packages/astro/src/assets/index.ts
+++ b/packages/astro/src/assets/index.ts
@@ -1,5 +1,5 @@
 export { getConfiguredImageService, getImage } from './internal.js';
-export { baseService } from './services/service.js';
+export { baseService, isLocalService } from './services/service.js';
 export { type LocalImageProps, type RemoteImageProps } from './types.js';
 export { emitESMImage } from './utils/emitAsset.js';
 export { imageMetadata } from './utils/metadata.js';
diff --git a/packages/astro/src/assets/internal.ts b/packages/astro/src/assets/internal.ts
index 5c5d82e77..f38b88124 100644
--- a/packages/astro/src/assets/internal.ts
+++ b/packages/astro/src/assets/internal.ts
@@ -4,7 +4,7 @@ import type { StaticBuildOptions } from '../core/build/types.js';
 import { AstroError, AstroErrorData } from '../core/errors/index.js';
 import { prependForwardSlash } from '../core/path.js';
 import { isLocalService, type ImageService, type LocalImageService } from './services/service.js';
-import type { ImageMetadata, ImageTransform } from './types.js';
+import type { GetImageResult, ImageMetadata, ImageTransform } from './types.js';
 
 export function isESMImportedImage(src: ImageMetadata | string): src is ImageMetadata {
 	return typeof src === 'object';
@@ -29,13 +29,6 @@ export async function getConfiguredImageService(): Promise<ImageService> {
 	return globalThis.astroAsset.imageService;
 }
 
-interface GetImageResult {
-	rawOptions: ImageTransform;
-	options: ImageTransform;
-	src: string;
-	attributes: Record<string, any>;
-}
-
 /**
  * Get an optimized image and the necessary attributes to render it.
  *
@@ -45,7 +38,7 @@ interface GetImageResult {
  * import { getImage } from 'astro:assets';
  * import originalImage from '../assets/image.png';
  *
- * const optimizedImage = await getImage({src: originalImage, width: 1280 })
+ * const optimizedImage = await getImage({src: originalImage, width: 1280 });
  * ---
  * <img src={optimizedImage.src} {...optimizedImage.attributes} />
  * ```
diff --git a/packages/astro/src/assets/services/service.ts b/packages/astro/src/assets/services/service.ts
index 693ced00f..b167f6aa2 100644
--- a/packages/astro/src/assets/services/service.ts
+++ b/packages/astro/src/assets/services/service.ts
@@ -1,7 +1,6 @@
 import { AstroError, AstroErrorData } from '../../core/errors/index.js';
 import { VALID_INPUT_FORMATS } from '../consts.js';
-import { isESMImportedImage } from '../internal.js';
-import type { ImageTransform, OutputFormat } from '../types.js';
+import { isESMImportedImage } from '../internal.js';import type { ImageOutputFormat, ImageTransform } from '../types.js';
 
 export type ImageService = LocalImageService | ExternalImageService;
 
@@ -71,7 +70,7 @@ export interface LocalImageService extends SharedServiceProps {
 	transform: (
 		inputBuffer: Buffer,
 		transform: LocalImageTransform
-	) => Promise<{ data: Buffer; format: OutputFormat }>;
+	) => Promise<{ data: Buffer; format: ImageOutputFormat }>;
 }
 
 export type BaseServiceTransform = {
@@ -204,7 +203,7 @@ export const baseService: Omit<LocalImageService, 'transform'> = {
 			src: params.get('href')!,
 			width: params.has('w') ? parseInt(params.get('w')!) : undefined,
 			height: params.has('h') ? parseInt(params.get('h')!) : undefined,
-			format: params.get('f') as OutputFormat,
+			format: params.get('f') as ImageOutputFormat,
 			quality: params.get('q'),
 		};
 
diff --git a/packages/astro/src/assets/services/sharp.ts b/packages/astro/src/assets/services/sharp.ts
index d68f8be43..04ddf77fa 100644
--- a/packages/astro/src/assets/services/sharp.ts
+++ b/packages/astro/src/assets/services/sharp.ts
@@ -1,5 +1,5 @@
 import type { FormatEnum } from 'sharp';
-import type { ImageQualityPreset, OutputFormat } from '../types.js';
+import type { ImageOutputFormat, ImageQualityPreset } from '../types.js';
 import {
 	baseService,
 	parseQuality,
@@ -64,7 +64,7 @@ const sharpService: LocalImageService = {
 
 		return {
 			data: data,
-			format: info.format as OutputFormat,
+			format: info.format as ImageOutputFormat,
 		};
 	},
 };
diff --git a/packages/astro/src/assets/services/squoosh.ts b/packages/astro/src/assets/services/squoosh.ts
index 25cc27939..089fcbc81 100644
--- a/packages/astro/src/assets/services/squoosh.ts
+++ b/packages/astro/src/assets/services/squoosh.ts
@@ -1,6 +1,6 @@
 // TODO: Investigate removing this service once sharp lands WASM support, as libsquoosh is deprecated
 
-import type { ImageQualityPreset, OutputFormat } from '../types.js';
+import type { ImageOutputFormat, ImageQualityPreset } from '../types.js';
 import {
 	baseService,
 	parseQuality,
@@ -11,7 +11,10 @@ import { processBuffer } from './vendor/squoosh/image-pool.js';
 import type { Operation } from './vendor/squoosh/image.js';
 
 const baseQuality = { low: 25, mid: 50, high: 80, max: 100 };
-const qualityTable: Record<Exclude<OutputFormat, 'png'>, Record<ImageQualityPreset, number>> = {
+const qualityTable: Record<
+	Exclude<ImageOutputFormat, 'png'>,
+	Record<ImageQualityPreset, number>
+> = {
 	avif: {
 		// Squoosh's AVIF encoder has a bit of a weird behavior where `62` is technically the maximum, and anything over is overkill
 		max: 62,
diff --git a/packages/astro/src/assets/services/vendor/squoosh/image-pool.ts b/packages/astro/src/assets/services/vendor/squoosh/image-pool.ts
index ac72fc4ef..73bd8545b 100644
--- a/packages/astro/src/assets/services/vendor/squoosh/image-pool.ts
+++ b/packages/astro/src/assets/services/vendor/squoosh/image-pool.ts
@@ -1,7 +1,7 @@
 import { isMainThread } from 'node:worker_threads';
 import { cpus } from 'os';
 import { fileURLToPath } from 'url';
-import type { OutputFormat } from '../../../types.js';
+import type { ImageOutputFormat } from '../../../types.js';
 import { getModuleURL } from './emscripten-utils.js';
 import type { Operation } from './image.js';
 import * as impl from './impl.js';
@@ -88,7 +88,7 @@ function handleJob(params: JobMessage) {
 export async function processBuffer(
 	buffer: Buffer,
 	operations: Operation[],
-	encoding: OutputFormat,
+	encoding: ImageOutputFormat,
 	quality?: number
 ): Promise<Uint8Array> {
 	// @ts-ignore
diff --git a/packages/astro/src/assets/services/vendor/squoosh/image.ts b/packages/astro/src/assets/services/vendor/squoosh/image.ts
index 0b19c5091..4a05d212c 100644
--- a/packages/astro/src/assets/services/vendor/squoosh/image.ts
+++ b/packages/astro/src/assets/services/vendor/squoosh/image.ts
@@ -1,4 +1,4 @@
-import type { OutputFormat } from '../../../types.js';
+import type { ImageOutputFormat } from '../../../types.js';
 import * as impl from './impl.js';
 
 type RotateOperation = {
@@ -15,7 +15,7 @@ export type Operation = RotateOperation | ResizeOperation
 export async function processBuffer(
   buffer: Buffer,
   operations: Operation[],
-  encoding: OutputFormat,
+  encoding: ImageOutputFormat,
   quality?: number
 ): Promise<Uint8Array> {
   let imageData = await impl.decodeBuffer(buffer)
diff --git a/packages/astro/src/assets/types.ts b/packages/astro/src/assets/types.ts
index 846e4e4cd..91bf97732 100644
--- a/packages/astro/src/assets/types.ts
+++ b/packages/astro/src/assets/types.ts
@@ -4,8 +4,8 @@ import type { ImageService } from './services/service.js';
 
 export type ImageQualityPreset = 'low' | 'mid' | 'high' | 'max' | (string & {});
 export type ImageQuality = ImageQualityPreset | number;
-export type InputFormat = (typeof VALID_INPUT_FORMATS)[number] | 'svg';
-export type OutputFormat = (typeof VALID_OUTPUT_FORMATS)[number] | (string & {});
+export type ImageInputFormat = (typeof VALID_INPUT_FORMATS)[number] | 'svg';
+export type ImageOutputFormat = (typeof VALID_OUTPUT_FORMATS)[number] | (string & {});
 
 declare global {
 	// eslint-disable-next-line no-var
@@ -23,7 +23,7 @@ export interface ImageMetadata {
 	src: string;
 	width: number;
 	height: number;
-	format: InputFormat;
+	format: ImageInputFormat;
 }
 
 /**
@@ -31,13 +31,20 @@ export interface ImageMetadata {
  */
 export type ImageTransform = {
 	src: ImageMetadata | string;
-	width?: number;
-	height?: number;
-	quality?: ImageQuality;
-	format?: OutputFormat;
+	width?: number | undefined;
+	height?: number | undefined;
+	quality?: ImageQuality | undefined;
+	format?: ImageOutputFormat | undefined;
 	[key: string]: any;
 };
 
+export interface GetImageResult {
+	rawOptions: ImageTransform;
+	options: ImageTransform;
+	src: string;
+	attributes: Record<string, any>;
+}
+
 type WithRequired<T, K extends keyof T> = T & { [P in K]-?: T[P] };
 type ImageSharedProps<T> = T & {
 	/**
@@ -94,11 +101,11 @@ export type LocalImageProps<T> = ImageSharedProps<T> & {
 	 * <Image src={...} format="avif" alt="..." />
 	 * ```
 	 */
-	format?: OutputFormat;
+	format?: ImageOutputFormat;
 	/**
 	 * Desired quality for the image. Value can either be a preset such as `low` or `high`, or a numeric value from 0 to 100.
 	 *
-	 * The perceptual quality of the output image is loader-specific.
+	 * The perceptual quality of the output image is service-specific.
 	 * For instance, a certain service might decide that `high` results in a very beautiful image, but another could choose for it to be at best passable.
 	 *
 	 * **Example**:
diff --git a/packages/astro/src/assets/utils/metadata.ts b/packages/astro/src/assets/utils/metadata.ts
index 4a722d731..8d2b5c6a2 100644
--- a/packages/astro/src/assets/utils/metadata.ts
+++ b/packages/astro/src/assets/utils/metadata.ts
@@ -1,6 +1,6 @@
 import fs from 'node:fs/promises';
 import { fileURLToPath } from 'node:url';
-import type { ImageMetadata, InputFormat } from '../types.js';
+import type { ImageInputFormat, ImageMetadata } from '../types.js';
 import imageSize from '../vendor/image-size/index.js';
 
 export interface Metadata extends ImageMetadata {
@@ -31,7 +31,7 @@ export async function imageMetadata(
 		src: fileURLToPath(src),
 		width: isPortrait ? height : width,
 		height: isPortrait ? width : height,
-		format: type as InputFormat,
+		format: type as ImageInputFormat,
 		orientation,
 	};
 }
diff --git a/packages/astro/src/assets/utils/queryParams.ts b/packages/astro/src/assets/utils/queryParams.ts
index 980c3dcd9..18acc8876 100644
--- a/packages/astro/src/assets/utils/queryParams.ts
+++ b/packages/astro/src/assets/utils/queryParams.ts
@@ -1,4 +1,4 @@
-import type { ImageMetadata, InputFormat } from '../types.js';
+import type { ImageInputFormat, ImageMetadata } from '../types.js';
 
 export function getOrigQueryParams(
 	params: URLSearchParams
@@ -14,6 +14,6 @@ export function getOrigQueryParams(
 	return {
 		width: parseInt(width),
 		height: parseInt(height),
-		format: format as InputFormat,
+		format: format as ImageInputFormat,
 	};
 }
diff --git a/packages/astro/src/assets/vite-plugin-assets.ts b/packages/astro/src/assets/vite-plugin-assets.ts
index 7c0186544..3512303f3 100644
--- a/packages/astro/src/assets/vite-plugin-assets.ts
+++ b/packages/astro/src/assets/vite-plugin-assets.ts
@@ -80,7 +80,7 @@ export default function assets({
 			load(id) {
 				if (id === resolvedVirtualModuleId) {
 					return `
-					export { getImage, getConfiguredImageService } from "astro/assets";
+					export { getImage, getConfiguredImageService, isLocalService } from "astro/assets";
 					export { default as Image } from "astro/components/Image.astro";
 				`;
 				}