feat(cli): support `webpack-command`

bin/webpack.js

@@ -21,61 +21,106 @@ function runCommand(command, options) {
 	});
 }
 
-let webpackCliInstalled = false;
-try {
-	require.resolve("webpack-cli");
-	webpackCliInstalled = true;
-} catch (err) {
-	webpackCliInstalled = false;
+function isInstalled(packageName) {
+	try {
+		require.resolve(packageName);
+
+		return true;
+	} catch (err) {
+		return false;
+	}
 }
 
-if (!webpackCliInstalled) {
+const CLI = [
+	{
+		name: "webpack-cli",
+		installed: isInstalled("webpack-cli"),
+		URL: "https://github.com/webpack/webpack-cli",
+		description: "The original webpack full-featured CLI from webpack@3."
+	},
+	{
+		name: "webpack-command",
+		installed: isInstalled("webpack-command"),
+		URL: "https://github.com/webpack-contrib/webpack-command",
+		description: "A lightweight, opinionated webpack CLI."
+	}
+];
+
+if (CLI.every(item => !item.installed)) {
 	const path = require("path");
 	const fs = require("fs");
 	const readLine = require("readline");
+
+	let notify =
+		"The CLI for webpack must be installed as a separate package, for which there are choices:\n";
+
+	CLI.forEach(item => {
+		notify += `    ${item.name} (${item.URL}): ${item.description}\n`;
+	});
+
+	console.error(notify);
+
 	const isYarn = fs.existsSync(path.resolve(process.cwd(), "yarn.lock"));
 
 	const packageManager = isYarn ? "yarn" : "npm";
-	const options = ["install", "-D", "webpack-cli"];
+	const installOptions = ["install", "-D"];
 
 	if (isYarn) {
-		options[0] = "add";
+		installOptions[0] = "add";
 	}
 
-	const commandToBeRun = `${packageManager} ${options.join(" ")}`;
+	let question = `Would you like to install (${CLI.map(item => item.name).join(
+		"/"
+	)}):\n`;
 
-	const question = `Would you like to install webpack-cli? (That will run ${commandToBeRun}) (yes/NO)`;
-
-	console.error("The CLI moved into a separate package: webpack-cli");
 	const questionInterface = readLine.createInterface({
 		input: process.stdin,
 		output: process.stdout
 	});
 	questionInterface.question(question, answer => {
 		questionInterface.close();
-		switch (answer.toLowerCase()) {
-			case "y":
-			case "yes":
-			case "1": {
-				runCommand(packageManager, options)
-					.then(result => {
-						return require("webpack-cli"); //eslint-disable-line
-					})
-					.catch(error => {
-						console.error(error);
-						process.exitCode = 1;
-					});
-				break;
-			}
-			default: {
-				console.error(
-					"It needs to be installed alongside webpack to use the CLI"
-				);
-				process.exitCode = 1;
-				break;
-			}
+
+		const normalizedAnswer = answer.toLowerCase();
+		const selectedPackage = CLI.find(item => item.name === normalizedAnswer);
+
+		if (!selectedPackage) {
+			console.error(
+				"It needs to be installed alongside webpack to use the CLI"
+			);
+			process.exitCode = 1;
+
+			return;
 		}
+
+		installOptions.push(normalizedAnswer);
+
+		console.log(
+			`Installing '${normalizedAnswer}' (running '${packageManager} ${installOptions.join(
+				" "
+			)}')...`
+		);
+
+		runCommand(packageManager, installOptions)
+			.then(result => {
+				return require(normalizedAnswer); //eslint-disable-line
+			})
+			.catch(error => {
+				console.error(error);
+				process.exitCode = 1;
+			});
 	});
 } else {
-	require("webpack-cli"); // eslint-disable-line
+	const installedPackage = CLI.map(
+		item => (item.installed ? item.name : "")
+	).filter(v => v);
+
+	if (installedPackage.length > 1) {
+		console.warn(
+			`You have installed ${installedPackage.join(
+				" and "
+			)} together. To work with the webpack you need only one CLI package, please remove one of them`
+		);
+	}
+
+	require(installedPackage[0]); // eslint-disable-line
 }

declarations.d.ts

@@ -1,5 +1,6 @@
 declare module "*.json";
 declare module "webpack-cli";
+declare module "webpack-command";
 
 // Deprecated NodeJS API usages in Webpack
 declare namespace NodeJS {