add install manager script

Author: Raul Melo

scripts/templates/install-manager.mjs

@@ -0,0 +1,224 @@
+#!/usr/bin/env node
+
+import * as path from "node:path";
+import * as fs from "node:fs";
+import https from "https";
+import tar from "tar";
+import { pipeline } from "stream/promises";
+
+// Mapping from Node's `process.arch` to Golang's `$GOARCH`
+const ARCH_MAPPING = {
+	ia32: "386",
+	x64: "amd64",
+	arm: "arm",
+	arm64: "arm64",
+};
+
+// Mapping between Node's `process.platform` to Golang's
+const PLATFORM_MAPPING = {
+	darwin: "darwin",
+	linux: "linux",
+	win32: "windows",
+	freebsd: "freebsd",
+};
+
+const command = process.argv[2];
+
+if (command === "install") {
+	await install();
+} else if (command === "uninstall") {
+	// do something
+} else {
+	console.log(
+		"Invalid command. 'install' and 'uninstall' are the only supported commands",
+	);
+	process.exit(1);
+}
+
+async function install() {
+	console.log("Installing binary...");
+	validateOsAndArch();
+	const pkgJson = readPackageJson();
+	const metaData = getMetaData(pkgJson);
+	createBinPath(metaData.binPath);
+
+	try {
+		await downloadFile(metaData.url, metaData.binTarGz);
+		await tar.x({
+			file: metaData.binTarGz,
+			cwd: metaData.binPath,
+		});
+
+		console.log("Binary installed successfully");
+	} catch (error) {
+		console.error(`Error downloading binary: ${error}`);
+		process.exit(1);
+	}
+}
+
+function readPackageJson() {
+	const packageJsonPath = path.join(".", "package.json");
+
+	if (!fs.existsSync(packageJsonPath)) {
+		console.error("package.json not found in current directory");
+		process.exit(1);
+	}
+
+	const packageJson = JSON.parse(fs.readFileSync(packageJsonPath, "utf-8"));
+	const err = validateConfiguration(packageJson);
+
+	if (err) {
+		console.error(err);
+		process.exit(1);
+	}
+
+	return packageJson;
+}
+
+/**
+ * @typedef {Object} GoBinary
+ * @property {(string|undefined)} path - The path of the Go binary.
+ * @property {(string|undefined)} name - The name of the Go binary.
+ * @property {(string|undefined)} url - The URL of the Go binary.
+ */
+
+/**
+ * @typedef {Object} PackageJson
+ * @property {(GoBinary|undefined)} goBinary - The goBinary object.
+ * @property {string} version - The version of the package.
+ */
+
+/**
+ * @typedef {Object} MetaData
+ * @property {string} binName - The name of the binary.
+ * @property {string} binPath - The path of the binary.
+ * @property {string} url - The URL of the binary.
+ * @property {string} version - The version of the binary.
+ */
+
+/**
+ * Extracts metadata from a package.json object.
+ *
+ * @param {PackageJson} packageJson - The package.json object.
+ *
+ * @returns {MetaData} An object containing the binary name, path, URL, and version.
+ */
+function getMetaData(packageJson) {
+	const binPath = packageJson.goBinary.path;
+	let binName = packageJson.goBinary.name;
+	let url = packageJson.goBinary.url;
+	let version = packageJson.version;
+
+	if (version[0] === "v") {
+		version = version.substring(1); // strip the 'v' if necessary v0.0.1 => 0.0.1
+	}
+
+	// Binary name on Windows has .exe suffix
+	if (process.platform === "win32") {
+		binName += ".exe";
+	}
+
+	// Interpolate variables in URL, if necessary
+	url = url.replace(/{{arch}}/g, ARCH_MAPPING[process.arch]);
+	url = url.replace(/{{platform}}/g, PLATFORM_MAPPING[process.platform]);
+	url = url.replace(/{{version}}/g, version);
+	url = url.replace(/{{bin_name}}/g, binName);
+
+	return {
+		binName,
+		binPath,
+		binFullName: path.join(process.cwd(), binPath),
+		get binTarGz() {
+			return `${this.binFullName}.tar.gz`;
+		},
+		url,
+		version,
+	};
+}
+
+function validateOsAndArch() {
+	if (!(process.arch in ARCH_MAPPING)) {
+		console.error(`Invalid architecture: ${process.arch}`);
+		process.exit(1);
+	}
+
+	if (!(process.platform in PLATFORM_MAPPING)) {
+		console.error(`Invalid platform: ${process.platform} `);
+		process.exit(1);
+	}
+}
+
+/**
+ * Validates the package.json object.
+ * @param {PackageJson} packageJson - The package.json object.
+ * @returns {string} An error message if the package.json object is invalid.
+ */
+function validateConfiguration(packageJson) {
+	if (!packageJson.version) {
+		return "'version' property must be specified";
+	}
+
+	if (!packageJson.goBinary || typeof packageJson.goBinary !== "object") {
+		return "'goBinary' property must be defined and be an object";
+	}
+
+	if (!packageJson.goBinary.name) {
+		return "'name' property is necessary";
+	}
+
+	if (!packageJson.goBinary.path) {
+		return "'path' property is necessary";
+	}
+
+	if (!packageJson.goBinary.url) {
+		return "'url' property is required";
+	}
+}
+
+/**
+ * Creates a directory at the specified path.
+ * @param {string} binPath - The path of the directory to create.
+ */
+function createBinPath(binPath) {
+	if (!fs.existsSync(binPath)) {
+		fs.mkdirSync(binPath, { recursive: true });
+	}
+}
+
+/**
+ * Downloads a file from a given URL and saves it to the specified path.
+ *
+ * @param {string} url - The URL of the file to download.
+ * @param {string} outputPath - The path where the downloaded file should be saved.
+ * @returns {Promise<string>} A promise that resolves with the path of the downloaded file.
+ * @throws {Error} Throws an error if the download or file writing fails.
+ */
+async function downloadFile(url, outputPath) {
+	return new Promise((resolve, reject) => {
+		const processResponse = (response) => {
+			// Check if the response is a redirect
+			if (
+				response.statusCode >= 300 &&
+				response.statusCode < 400 &&
+				response.headers.location
+			) {
+				https
+					.get(response.headers.location, processResponse)
+					.on("error", reject);
+			} else if (response.statusCode === 200) {
+				const fileStream = fs.createWriteStream(outputPath);
+				pipeline(response, fileStream)
+					.then(() => resolve(outputPath))
+					.catch((error) => {
+						reject(`Error during download: ${error.message}`);
+					});
+			} else {
+				reject(
+					`Server responded with ${response.statusCode}: ${response.statusMessage}`,
+				);
+			}
+		};
+
+		https.get(url, processResponse).on("error", reject);
+	});
+}