VercelBuilder Class — astro Architecture

Source Code

packages/integrations/vercel/src/index.ts lines 645–727

class VercelBuilder {
	readonly NTF_CACHE = {};

	constructor(
		readonly config: AstroConfig,
		readonly excludeFiles: URL[],
		readonly includeFiles: URL[],
		readonly logger: AstroIntegrationLogger,
		readonly outDir: URL,
		readonly maxDuration?: number,
		readonly runtime = getRuntime(process, logger),
	) {}

	async buildServerlessFolder(entry: URL, functionName: string, root: URL) {
		const { includeFiles, excludeFiles, logger, NTF_CACHE, runtime, maxDuration } = this;
		// .vercel/output/functions/<name>.func/
		const functionFolder = new URL(`./functions/${functionName}.func/`, this.outDir);
		const packageJson = new URL(`./functions/${functionName}.func/package.json`, this.outDir);
		const vcConfig = new URL(`./functions/${functionName}.func/.vc-config.json`, this.outDir);

		// Copy necessary files (e.g. node_modules/)
		const { handler } = await copyDependenciesToFunction(
			{
				entry,
				outDir: functionFolder,
				includeFiles,
				excludeFiles,
				logger,
				root,
			},
			NTF_CACHE,
		);

		// Enable ESM
		// https://aws.amazon.com/blogs/compute/using-node-js-es-modules-and-top-level-await-in-aws-lambda/
		await writeJson(packageJson, {
			type: 'module',
		});

		// Serverless function config
		// https://vercel.com/docs/build-output-api/v3#vercel-primitives/serverless-functions/configuration
		await writeJson(vcConfig, {
			runtime,
			handler: handler.replaceAll('\\', '/'),
			launcherType: 'Nodejs',
			maxDuration,
			supportsResponseStreaming: true,
		});
	}

	async buildISRFolder(entry: URL, functionName: string, isr: VercelISRConfig, root: URL) {
		await this.buildServerlessFolder(entry, functionName, root);
		const prerenderConfig = new URL(
			`./functions/${functionName}.prerender-config.json`,
			this.outDir,
		);
		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
		await writeJson(prerenderConfig, {
			expiration: isr.expiration ?? false,
			bypassToken: isr.bypassToken,
			allowQuery: [ASTRO_PATH_PARAM],
			passQuery: true,
		});
	}

	async buildMiddlewareFolder(entry: URL, functionName: string, middlewareSecret: string) {
		const functionFolder = new URL(`./functions/${functionName}.func/`, this.outDir);

		await generateEdgeMiddleware(
			entry,
			this.config.root,
			new URL(VERCEL_EDGE_MIDDLEWARE_FILE, this.config.srcDir),
			new URL('./middleware.mjs', functionFolder),
			middlewareSecret,
			this.logger,
		);

		await writeJson(new URL(`./.vc-config.json`, functionFolder), {
			runtime: 'edge',
			entrypoint: 'middleware.mjs',
		});