refactor: top level nextjs adapter function

part of opral/inlang-paraglide-js#338

inlang/packages/paraglide/paraglide-next/example/next.config.mjs

@@ -1,23 +1,13 @@
-import { paraglideWebpackPlugin } from "@inlang/paraglide-js";
-import { ParaglideNext } from "@inlang/paraglide-next";
+import { withParaglideNext } from "@inlang/paraglide-next";
 
-/** @type {import("next").NextConfig} */
-const nextConfig = {
+export default withParaglideNext({
+	paraglide: {
+		outdir: "./src/paraglide",
+		project: "./project.inlang",
+	},
 	eslint: {
 		// Warning: This allows production builds to successfully complete even if
 		// your project has ESLint errors.
 		ignoreDuringBuilds: true,
 	},
-	webpack: (config) => {
-		config.plugins.push(
-			paraglideWebpackPlugin({
-				project: "./project.inlang",
-				outdir: "./src/paraglide",
-				adapter: ParaglideNext(),
-			})
-		);
-		return config;
-	},
-};
-
-export default nextConfig;
+});

inlang/packages/paraglide/paraglide-next/src/index.ts

@@ -1,5 +1,9 @@
-import type { Adapter } from "@inlang/paraglide-js";
 import fs from "node:fs";
+import type { NextConfig } from "next";
+import {
+	paraglideWebpackPlugin,
+	type CompilerArgs,
+} from "@inlang/paraglide-js";
 
 /**
  * Reads a file from the file system and returns it as a string.
@@ -8,11 +12,41 @@ const file = (path: string) => ({
 	[path]: fs.readFileSync(new URL(path, import.meta.url), "utf-8"),
 });
 
-export const ParaglideNext: () => Adapter = () => {
-	const files = {
-		...file("adapter.js"),
-		...file("adapter.provider.jsx"),
-		...file("adapter.provider.client.jsx"),
+/**
+ * Extends a Next.js configuration with Paraglide.
+ *
+ * @example
+ *   // next.config.mjs
+ *   import { withParaglideNext } from "@inlang/paraglide-next";
+ *   export default withParaglideNext({
+ *     paraglide: {
+ *       project: "./project.inlang",
+ *       outdir: "./src/lib/paraglide",
+ *     },
+ *     // other Next.js configuration
+ *   });
+ */
+export function withParaglideNext(
+	config: NextConfig & {
+		paraglide: CompilerArgs;
+	}
+): NextConfig {
+	const extendedConfig: NextConfig = {
+		...config,
+		webpack: (webpackConfig) => {
+			webpackConfig.plugins.push(
+				paraglideWebpackPlugin({
+					...config.paraglide,
+					additionalFiles: {
+						...file("adapter.js"),
+						...file("adapter.provider.jsx"),
+						...file("adapter.provider.client.jsx"),
+					},
+				})
+			);
+			return webpackConfig;
+		},
 	};
-	return { files };
-};
+	delete extendedConfig.paraglide;
+	return extendedConfig;
+}