bootstrap-import.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

// *********************************************************************
// *                                                                   *
// *  We need this to redirect to node_modules from the remote-folder. *
// *  This ONLY applies  when running out of source.                   *
// *                                                                   *
// *********************************************************************

import { promises } from "node:fs";
import { join } from "node:path";
import { fileURLToPath, pathToFileURL } from "node:url";

// SEE https://nodejs.org/docs/latest/api/module.html#initialize

const _specifierToUrl: Record<string, string> = {};

export async function initialize(injectPath: string): Promise<void> {
	// populate mappings

	const injectPackageJSONPath = fileURLToPath(
		new URL("../package.json", pathToFileURL(injectPath)),
	);
	const packageJSON = JSON.parse(
		String(await promises.readFile(injectPackageJSONPath)),
	);

	for (const [name] of Object.entries(packageJSON.dependencies)) {
		try {
			const path = join(
				injectPackageJSONPath,
				`../node_modules/${name}/package.json`,
			);
			let { main } = JSON.parse(String(await promises.readFile(path)));

			if (!main) {
				main = "index.js";
			}
			if (!main.endsWith(".js")) {
				main += ".js";
			}
			const mainPath = join(
				injectPackageJSONPath,
				`../node_modules/${name}/${main}`,
			);
			_specifierToUrl[name] = pathToFileURL(mainPath).href;
		} catch (err) {
			console.error(name);
			console.error(err);
		}
	}

	console.log(
		`[bootstrap-import] Initialized node_modules redirector for: ${injectPath}`,
	);
}

export async function resolve(
	specifier: string | number,
	context: any,
	nextResolve: (arg0: any, arg1: any) => any,
) {
	const newSpecifier = _specifierToUrl[specifier];
	if (newSpecifier !== undefined) {
		return {
			format: "commonjs",
			shortCircuit: true,
			url: newSpecifier,
		};
	}

	// Defer to the next hook in the chain, which would be the
	// Node.js default resolve if this is the last user-specified loader.
	return nextResolve(specifier, context);
}