astro/packages/integrations/netlify/src/integration-static.ts

import type { AstroIntegration, RouteData } from 'astro';
import { createRedirects } from './shared.js';

export function netlifyStatic(): AstroIntegration {
	let _config: any;
	return {
		name: '@astrojs/netlify',
		hooks: {
			'astro:config:setup': ({ updateConfig }) => {
				updateConfig({
					build: {
						// Do not output HTML redirects because we are building a `_redirects` file.
						redirects: false,
					},
				});
			},
			'astro:config:done': ({ config }) => {
				_config = config;
			},
			'astro:build:done': async ({ dir, routes }) => {
				const mappedRoutes: [RouteData, string][] = routes.map((route) => [
					route,
					`/.netlify/static/`,
				]);
				const routesToDynamicTargetMap = new Map(Array.from(mappedRoutes));
				await createRedirects(_config, routesToDynamicTargetMap, dir);
			},
		},
	};
}