astro/dist/core/build/vite-build-config.js

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

import { fileURLToPath } from "node:url";
import { getClientOutputDirectory, getPrerenderOutputDirectory, getServerOutputDirectory } from "../../prerender/utils.js";
import { VIRTUAL_PAGE_RESOLVED_MODULE_ID } from "../../vite-plugin-pages/const.js";
import { ASTRO_VITE_ENVIRONMENT_NAMES } from "../constants.js";
import { CHUNKS_PATH } from "./consts.js";
import { isLegacyAdapter, LEGACY_SSR_ENTRY_VIRTUAL_MODULE, RESOLVED_LEGACY_SSR_ENTRY_VIRTUAL_MODULE } from "./plugins/plugin-ssr.js";
import { ASTRO_PAGE_EXTENSION_POST_PATTERN } from "./plugins/util.js";
import { getImageServiceEnvironmentOptions } from "./image-service.js";
import { IMAGE_SERVICE_ENVIRONMENT_NAME } from "../../assets/consts.js";
import { cleanChunkName } from "./util.js";
import { makeAstroPageEntryPointFileName } from "./static-build.js";
const PRERENDER_ENTRY_FILENAME_PREFIX = "prerender-entry";
/**
* Creates the Vite InlineConfig used for the multi-environment build.
*
* This is a pure config assembly function — it does not execute the build.
* Extracted from `buildEnvironments()` to enable unit testing of config
* merging behavior (e.g. user rollup output overrides).
*/
export function createViteBuildConfig(opts) {
	const { settings, viteConfig, routes, plugins, builder, isRolldownInput } = opts;
	const legacyAdapter = !settings.adapter || isLegacyAdapter(settings.adapter);
	// Separate Astro-managed environment keys from user-defined ones so that the
	// managed environments always appear last (and in a fixed order) in the object.
	// Vite's `configResolved` fires per environment in key-insertion order, and the
	// `astro:resolve-input` plugin relies on `ssr` being resolved last so its
	// rolldown input value is the one that persists. If a user-defined
	// `environments.ssr` is spread first, its key position would place SSR earlier
	// in the iteration order, causing later environments to overwrite the saved
	// input. See https://github.com/withastro/astro/issues/17760
	const { [ASTRO_VITE_ENVIRONMENT_NAMES.ssr]: userSsr, [ASTRO_VITE_ENVIRONMENT_NAMES.prerender]: userPrerender, [ASTRO_VITE_ENVIRONMENT_NAMES.client]: userClient, ...userEnvironments } = viteConfig.environments ?? {};
	return {
		...viteConfig,
		logLevel: viteConfig.logLevel ?? "error",
		build: {
			target: "esnext",
			// Vite defaults cssMinify to false in SSR by default, but we want to minify it
			// as the CSS generated are used and served to the client.
			cssMinify: viteConfig.build?.minify == null ? true : !!viteConfig.build?.minify,
			...viteConfig.build,
			emptyOutDir: false,
			copyPublicDir: false,
			manifest: false,
			rolldownOptions: {
				...viteConfig.build?.rolldownOptions,
				// Setting as `exports-only` allows us to safely delete inputs that are only used during prerendering
				preserveEntrySignatures: "exports-only",
				checks: {
					...viteConfig.build?.rolldownOptions?.checks,
					// Disable Rolldown's built-in plugin timing warnings. These fire by default
					// and produce noisy warnings about slow plugins during normal builds.
					pluginTimings: false
				},
				...legacyAdapter && settings.buildOutput === "server" ? { input: LEGACY_SSR_ENTRY_VIRTUAL_MODULE } : {},
				output: {
					hoistTransitiveImports: false,
					format: "esm",
					minifyInternalExports: true,
					// Server chunks can't go in the assets (_astro) folder
					// We need to keep these separate
					chunkFileNames(chunkInfo) {
						const { name } = chunkInfo;
						let prefix = CHUNKS_PATH;
						let suffix = "_[hash].mjs";
						// Sometimes chunks have the `@_@astro` suffix due to SSR logic. Remove it!
						// TODO: refactor our build logic to avoid this
						if (name.includes(ASTRO_PAGE_EXTENSION_POST_PATTERN)) {
							const [sanitizedName] = name.split(ASTRO_PAGE_EXTENSION_POST_PATTERN);
							return [
								prefix,
								cleanChunkName(sanitizedName),
								suffix
							].join("");
						}
						// Injected routes include "pages/[name].[ext]" already. Clean those up!
						if (name.startsWith("pages/")) {
							const sanitizedName = name.split(".")[0];
							return [
								prefix,
								cleanChunkName(sanitizedName),
								suffix
							].join("");
						}
						return [
							prefix,
							cleanChunkName(name),
							suffix
						].join("");
					},
					assetFileNames(assetInfo) {
						// Strip the @_@ extension-masking pattern from asset names, just like chunkFileNames above.
						// The @_@ pattern is an internal mechanism for virtual module IDs and should not leak into output filenames.
						const name = assetInfo.names?.[0] ?? "";
						if (name.includes(ASTRO_PAGE_EXTENSION_POST_PATTERN)) {
							const [sanitizedName] = name.split(ASTRO_PAGE_EXTENSION_POST_PATTERN);
							return `${settings.config.build.assets}/${sanitizedName}.[hash][extname]`;
						}
						return `${settings.config.build.assets}/[name].[hash][extname]`;
					},
					...viteConfig.build?.rolldownOptions?.output,
					entryFileNames(chunkInfo) {
						if (chunkInfo.facadeModuleId?.startsWith(VIRTUAL_PAGE_RESOLVED_MODULE_ID)) {
							return makeAstroPageEntryPointFileName(VIRTUAL_PAGE_RESOLVED_MODULE_ID, chunkInfo.facadeModuleId, routes);
						} else if (chunkInfo.facadeModuleId === RESOLVED_LEGACY_SSR_ENTRY_VIRTUAL_MODULE || isRolldownInput(chunkInfo.name) || isRolldownInput(chunkInfo.facadeModuleId)) {
							return settings.config.build.serverEntry;
						} else {
							return "[name].mjs";
						}
					}
				}
			},
			ssr: true,
			ssrEmitAssets: true,
			// improve build performance
			minify: false,
			modulePreload: { polyfill: false },
			reportCompressedSize: false
		},
		plugins,
		builder,
		envPrefix: viteConfig.envPrefix ?? "PUBLIC_",
		base: settings.config.base,
		environments: {
			...userEnvironments,
			[IMAGE_SERVICE_ENVIRONMENT_NAME]: getImageServiceEnvironmentOptions(settings),
			[ASTRO_VITE_ENVIRONMENT_NAMES.prerender]: {
				...userPrerender,
				build: {
					emitAssets: true,
					outDir: fileURLToPath(getPrerenderOutputDirectory(settings)),
					rolldownOptions: {
						// Only skip the default prerender entrypoint if an adapter with `entrypointResolution: 'self'` is used
						// AND provides a custom prerenderer. Otherwise, use the default.
						...!legacyAdapter && settings.prerenderer ? {} : { input: "astro/entrypoints/prerender" },
						output: {
							entryFileNames: `${PRERENDER_ENTRY_FILENAME_PREFIX}.[hash].mjs`,
							format: "esm",
							...userPrerender?.build?.rolldownOptions?.output
						}
					},
					ssr: true
				}
			},
			[ASTRO_VITE_ENVIRONMENT_NAMES.client]: {
				...userClient,
				build: {
					emitAssets: true,
					target: "esnext",
					outDir: fileURLToPath(getClientOutputDirectory(settings)),
					copyPublicDir: true,
					sourcemap: userClient?.build?.sourcemap ?? viteConfig.build?.sourcemap ?? false,
					minify: userClient?.build?.minify ?? viteConfig.build?.minify ?? true,
					rolldownOptions: {
						preserveEntrySignatures: "exports-only",
						output: {
							// Inherit top-level rolldown output options (e.g. compact) as a
							// base, then layer Astro defaults on top so that Astro's
							// naming functions are preserved unless explicitly overridden
							// via the environment-specific config.
							...viteConfig.build?.rolldownOptions?.output,
							entryFileNames(chunkInfo) {
								return `${settings.config.build.assets}/${cleanChunkName(chunkInfo.name)}.[hash].js`;
							},
							chunkFileNames(chunkInfo) {
								return `${settings.config.build.assets}/${cleanChunkName(chunkInfo.name)}.[hash].js`;
							},
							assetFileNames(assetInfo) {
								// Strip the @_@ extension-masking pattern from asset names.
								// The @_@ pattern is an internal mechanism for virtual module IDs and should not leak into output filenames.
								const name = assetInfo.names?.[0] ?? "";
								if (name.includes(ASTRO_PAGE_EXTENSION_POST_PATTERN)) {
									const [sanitizedName] = name.split(ASTRO_PAGE_EXTENSION_POST_PATTERN);
									return `${settings.config.build.assets}/${sanitizedName}.[hash][extname]`;
								}
								return `${settings.config.build.assets}/[name].[hash][extname]`;
							},
							...userClient?.build?.rolldownOptions?.output
						}
					}
				}
			},
			[ASTRO_VITE_ENVIRONMENT_NAMES.ssr]: {
				...userSsr,
				build: {
					outDir: fileURLToPath(getServerOutputDirectory(settings)),
					rolldownOptions: { output: { ...userSsr?.build?.rolldownOptions?.output } }
				}
			}
		}
	};
}