astro/dist/core/build/image-service.js

Astro is a modern site builder with web best practices, performance, and DX front-of-mind.

import { fileURLToPath } from "node:url";
import { IMAGE_SERVICE_ENVIRONMENT_NAME, VIRTUAL_SERVICE_ID } from "../../assets/consts.js";
import { isLocalService } from "../../assets/services/service.js";
import { getImageServiceConfig } from "../../assets/utils/service-config.js";
import { getPrerenderOutputDirectory } from "../../prerender/utils.js";
import { AstroError, AstroErrorData } from "../errors/index.js";
import { viteBuildReturnToRolldownOutputs } from "./util.js";
const IMAGE_SERVICE_ENTRY_NAME = "image-service";
const IMAGE_SERVICE_ENTRY_ID = "virtual:astro:image-service-entry";
const RESOLVED_IMAGE_SERVICE_ENTRY_ID = "\0" + IMAGE_SERVICE_ENTRY_ID;
function getImageServiceOutputDirectory(settings) {
	return new URL(`${IMAGE_SERVICE_ENTRY_NAME}/`, getPrerenderOutputDirectory(settings));
}
export function getImageServiceEnvironmentOptions(settings) {
	return {
		consumer: "server",
		// Keeps linked packages external too, so `sharp` resolves from `astro`.
		resolve: { external: true },
		build: {
			outDir: fileURLToPath(getImageServiceOutputDirectory(settings)),
			emitAssets: false,
			ssr: true,
			rolldownOptions: {
				// A string, so it replaces any shared `input` instead of being merged with it.
				input: IMAGE_SERVICE_ENTRY_ID,
				// Hashed, so a rebuild in the same process doesn't import a cached module.
				output: {
					entryFileNames: `${IMAGE_SERVICE_ENTRY_NAME}.[hash].mjs`,
					format: "esm"
				}
			}
		}
	};
}
// An entry can't be external, so this one re-exports the service.
export function pluginImageServiceEntry() {
	return {
		name: "@astro/plugin-image-service-entry",
		applyToEnvironment: (environment) => environment.name === IMAGE_SERVICE_ENVIRONMENT_NAME,
		resolveId: {
			filter: { id: new RegExp(`^${IMAGE_SERVICE_ENTRY_ID}$`) },
			handler: () => RESOLVED_IMAGE_SERVICE_ENTRY_ID
		},
		load: {
			filter: { id: new RegExp(`^${RESOLVED_IMAGE_SERVICE_ENTRY_ID}$`) },
			handler: () => `export { default } from ${JSON.stringify(VIRTUAL_SERVICE_ID)};`
		}
	};
}
export async function loadBuildImageService(builder, settings) {
	const { entrypoint } = getImageServiceConfig(settings.config.image.service, "build");
	let service;
	try {
		const output = await builder.build(builder.environments[IMAGE_SERVICE_ENVIRONMENT_NAME]);
		const entry = viteBuildReturnToRolldownOutputs(output).flatMap((o) => o.output).find((chunk) => chunk.type === "chunk" && chunk.isEntry);
		if (!entry) throw new Error("The image service build produced no entry chunk.");
		const url = new URL(entry.fileName, getImageServiceOutputDirectory(settings));
		service = (await import(url.href)).default;
	} catch (cause) {
		throw new AstroError({
			...AstroErrorData.InvalidImageService,
			message: `Could not load the image service \`${entrypoint}\` to generate images in Node.`
		}, { cause });
	}
	if (!isLocalService(service)) {
		throw new AstroError({
			...AstroErrorData.InvalidImageService,
			message: `The image service \`${entrypoint}\` generates prerendered images during the build, but it is not a local service: it doesn't implement \`transform()\`.`
		});
	}
	return service;
}