pages.ts — astro Source File

Source Code

import type { Plugin as VitePlugin } from 'vite';
import { DEFAULT_COMPONENTS } from '../core/routing/default.js';
import { routeIsRedirect } from '../core/routing/index.js';
import type { RoutesList } from '../types/astro.js';
import type { RouteData } from '../types/public/internal.js';
import { VIRTUAL_PAGE_MODULE_ID } from './const.js';
import { getVirtualModulePageName } from './util.js';
import { ASTRO_VITE_ENVIRONMENT_NAMES } from '../core/constants.js';

export const VIRTUAL_PAGES_MODULE_ID = 'virtual:astro:pages';
const VIRTUAL_PAGES_RESOLVED_MODULE_ID = '\0' + VIRTUAL_PAGES_MODULE_ID;

interface PagesPluginOptions {
	routesList: RoutesList;
}

/**
 * Filters routes for a specific build environment.
 * Redirects need their target route included so the redirect response can be generated at runtime.
 */
function getRoutesForEnvironment(routes: RouteData[], isPrerender: boolean): Set<RouteData> {
	const result = new Set<RouteData>();
	for (const route of routes) {
		if (route.prerender === isPrerender) {
			result.add(route);
		}
		if (route.redirectRoute) {
			result.add(route.redirectRoute);
		}
	}
	return result;
}

export function pluginPages({ routesList }: PagesPluginOptions): VitePlugin {
	return {
		name: '@astro/plugin-pages',
		enforce: 'post',
		applyToEnvironment(environment) {
			return (
				environment.name === ASTRO_VITE_ENVIRONMENT_NAMES.ssr ||
				environment.name === ASTRO_VITE_ENVIRONMENT_NAMES.prerender
			);
		},
		resolveId: {
			filter: {
				id: new RegExp(`^${VIRTUAL_PAGES_MODULE_ID}$`),
			},
			handler() {
				return VIRTUAL_PAGES_RESOLVED_MODULE_ID;
			},
		},
		load: {
			filter: {
				id: new RegExp(`^${VIRTUAL_PAGES_RESOLVED_MODULE_ID}$`),
			},
			async handler() {
				const imports: string[] = [];
				const pageMap: string[] = [];
				let i = 0;

				// Filter routes based on the build environment to reduce memory usage.
				// Each environment only builds the pages it needs:
				// - SSR environment: builds only on-demand rendered pages (prerender: false)
				// - Prerender environment: builds only static pages (prerender: true)
				// - Other environments (e.g. client): get all routes
				const envName = this.environment.name;
				const isSSR = envName === ASTRO_VITE_ENVIRONMENT_NAMES.ssr;
				const isPrerender = envName === ASTRO_VITE_ENVIRONMENT_NAMES.prerender;
				const routes =
					isSSR || isPrerender
						? getRoutesForEnvironment(routesList.routes, isPrerender)
						: new Set(routesList.routes);

				for (const route of routes) {
					if (routeIsRedirect(route)) {
						continue;
					}

					// Skip default components (404, server islands, etc.)
					if (DEFAULT_COMPONENTS.some((component) => route.component === component)) {
						continue;
					}

					const virtualModuleName = getVirtualModulePageName(
						VIRTUAL_PAGE_MODULE_ID,
						route.component,
					);
					const module = await this.resolve(virtualModuleName);
					if (module) {
						const variable = `_page${i}`;
						// use the non-resolved ID to resolve correctly the virtual module
						imports.push(`const ${variable} = () => import("${virtualModuleName}");`);
						pageMap.push(`[${JSON.stringify(route.component)}, ${variable}]`);
						i++;
					}
				}

				const pageMapCode = `const pageMap = new Map([\n    ${pageMap.join(',\n    ')}\n]);\n\nexport { pageMap };`;
				return { code: [...imports, pageMapCode].join('\n') };
			},
		},
	};
}