astro/dist/core/preview/static-preview-server.js

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

import { performance } from "node:perf_hooks";
import { fileURLToPath } from "node:url";
import { mergeConfig, preview } from "vite";
import { getClientOutputDirectory } from "../../prerender/utils.js";
import * as msg from "../messages/runtime.js";
import { getResolvedHostForHttpServer } from "./util.js";
import { vitePluginAstroPreview } from "./vite-plugin-astro-preview.js";
import { BuildTimeAstroVersionProvider } from "../../cli/infra/build-time-astro-version-provider.js";
import { piccoloreTextStyler } from "../../cli/infra/piccolore-text-styler.js";
export default async function createStaticPreviewServer(settings, logger) {
	const startServerTime = performance.now();
	let previewServer;
	try {
		// Build the Astro-specific preview config
		const astroPreviewConfig = {
			configFile: false,
			base: settings.config.base,
			appType: "mpa",
			build: { outDir: fileURLToPath(getClientOutputDirectory(settings)) },
			root: fileURLToPath(settings.config.root),
			preview: {
				host: settings.config.server.host,
				port: settings.config.server.port,
				headers: settings.config.server.headers,
				open: settings.config.server.open
			},
			plugins: [vitePluginAstroPreview(settings)]
		};
		// Merge user's vite config (from astro.config.mjs `vite` field) as the base,
		// then apply Astro's overrides on top. This ensures vite.preview.* settings
		// are respected while Astro-specific values (like configFile: false) always win.
		// Plugins are excluded from the user config since Astro manages its own plugin set.
		const { plugins: _plugins, ...userViteConfig } = settings.config.vite ?? {};
		const mergedViteConfig = mergeConfig(userViteConfig, astroPreviewConfig);
		// Apply allowedHosts after merging to avoid Vite's array concatenation behavior.
		// If the user explicitly set server.allowedHosts in Astro config (boolean or non-empty
		// array), that takes precedence. Otherwise, the user's vite.preview.allowedHosts from
		// settings.config.vite (merged above) is preserved.
		const { allowedHosts } = settings.config.server;
		if (typeof allowedHosts === "boolean" || Array.isArray(allowedHosts) && allowedHosts.length > 0) {
			mergedViteConfig.preview ??= {};
			mergedViteConfig.preview.allowedHosts = allowedHosts;
		}
		previewServer = await preview(mergedViteConfig);
	} catch (err) {
		if (err instanceof Error) {
			logger.error(null, err.stack || err.message);
		}
		throw err;
	}
	// Set up shortcuts
	const customShortcuts = [
		(
		// Disable default Vite shortcuts that don't work well with Astro
		{
			key: "r",
			description: ""
		}),
		{
			key: "u",
			description: ""
		},
		{
			key: "c",
			description: ""
		},
		{
			key: "s",
			description: ""
		}
	];
	previewServer.bindCLIShortcuts({ customShortcuts });
	// Log server start URLs
	logger.info("SKIP_FORMAT", msg.serverStart({
		startupTime: performance.now() - startServerTime,
		resolvedUrls: previewServer.resolvedUrls ?? {
			local: [],
			network: []
		},
		host: settings.config.server.host,
		base: settings.config.base,
		astroVersionProvider: new BuildTimeAstroVersionProvider(),
		textStyler: piccoloreTextStyler
	}));
	// Resolves once the server is closed
	function closed() {
		return new Promise((resolve, reject) => {
			previewServer.httpServer.addListener("close", resolve);
			previewServer.httpServer.addListener("error", reject);
		});
	}
	// Read the actual bound port from the HTTP server, not the configured port.
	// This is important when port 0 is used (OS-assigned port).
	const address = previewServer.httpServer.address();
	const actualPort = address && typeof address === "object" ? address.port : settings.config.server.port;
	return {
		host: getResolvedHostForHttpServer(settings.config.server.host),
		port: actualPort,
		urls: previewServer.resolvedUrls ?? {
			local: [],
			network: []
		},
		closed,
		server: previewServer.httpServer,
		stop: previewServer.close.bind(previewServer)
	};
}