cli(add): support for webpack config file (#501)

* cli(add): add support for webpack config

* cli(utils): update signature for config helper

* chore(deps): add log-symbols

* cli: update modify-config-helper usage

packages/add/index.js

@@ -1,16 +1,23 @@
 "use strict";
 
 const defaultGenerator = require("@webpack-cli/generators/add-generator");
-const modifyHelper = require("@webpack-cli/utils/modify-config-helper");
+const modifyConfigHelper = require("@webpack-cli/utils/modify-config-helper");
 
 /**
  * Is called and returns a scaffolding instance, adding properties
  *
- * @returns {Function} modifyHelper - A helper function that uses the action
+ * @returns {Function} modifyConfigHelper - A helper function that uses the action
  * 	we're given on a generator
  *
  */
 
-module.exports = function add() {
-	return modifyHelper("add", defaultGenerator);
+module.exports = function add(...args) {
+	const DEFAULT_WEBPACK_CONFIG_FILENAME = "webpack.config.js";
+
+	const filePaths = args.slice(3);
+	let configFile = DEFAULT_WEBPACK_CONFIG_FILENAME;
+	if (filePaths.length) {
+		configFile = filePaths[0];
+	}
+	return modifyConfigHelper("add", defaultGenerator, configFile);
 };

packages/init/index.js

@@ -2,7 +2,7 @@
 
 const npmPackagesExists = require("@webpack-cli/utils/npm-packages-exists");
 const defaultGenerator = require("@webpack-cli/generators/init-generator");
-const modifyHelper = require("@webpack-cli/utils/modify-config-helper");
+const modifyConfigHelper = require("@webpack-cli/utils/modify-config-helper");
 
 /**
  *
@@ -19,7 +19,7 @@ module.exports = function initializeInquirer(...args) {
 	const packages = args.slice(3);
 
 	if (packages.length === 0) {
-		return modifyHelper("init", defaultGenerator);
+		return modifyConfigHelper("init", defaultGenerator);
 	}
 	return npmPackagesExists(packages);
 };