chore(types): add type information (#791)

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**What kind of change does this PR introduce?**
<!-- E.g. a bugfix, feature, refactoring, build related change, etc… -->
Adds some type related information and removed where it is obvious

**Did you add tests for your changes?**
N/A
**If relevant, did you update the documentation?**
N/A
**Summary**
leverage on type inference

r? @evenstensberg @ematipico  @dhruvdutt 
<!-- Explain the **motivation** for making this change. What existing problem does the pull request solve? -->
<!-- Try to link to an open issue for more information. -->

**Does this PR introduce a breaking change?**
<!-- If this PR introduces a breaking change, please describe the impact and a migration path for existing applications. -->

**Other information**

packages/add/index.ts

@@ -9,13 +9,13 @@ import modifyConfigHelper from "@webpack-cli/utils/modify-config-helper";
  * 	we're given on a generator
  *
  */
-const DEFAULT_WEBPACK_CONFIG_FILENAME: string = "webpack.config.js";
+const DEFAULT_WEBPACK_CONFIG_FILENAME = "webpack.config.js";
 
 export default function add(...args: string[]): Function {
-  const filePaths: string[] = args.slice(3);
-  let configFile: string = DEFAULT_WEBPACK_CONFIG_FILENAME;
+  const filePaths = args.slice(3);
+  let configFile = DEFAULT_WEBPACK_CONFIG_FILENAME;
   if (filePaths.length) {
-	configFile = filePaths[0];
+	  configFile = filePaths[0];
   }
 
   return modifyConfigHelper("add", defaultGenerator, configFile);

packages/generate-loader/index.ts

@@ -10,7 +10,7 @@ import { IYeoman } from "./types/Yeoman";
 
 export default function loaderCreator(): void {
 	const env = yeoman.createEnv();
-	const generatorName: string = "webpack-loader-generator";
+	const generatorName = "webpack-loader-generator";
 
 	env.registerStub(LoaderGenerator, generatorName);
 

packages/generate-plugin/index.ts

@@ -10,7 +10,7 @@ import { IYeoman } from "./types/Yeoman";
 
 export default function pluginCreator(): void {
 	const env = yeoman.createEnv();
-	const generatorName: string = "webpack-plugin-generator";
+	const generatorName = "webpack-plugin-generator";
 
 	env.registerStub(PluginGenerator, generatorName);
 

packages/generators/add-generator.ts

@@ -11,7 +11,6 @@ import {
 	AutoComplete,
 	Confirm,
 	IInquirerInput,
-	IInquirerList,
 	Input,
 	List,
 } from "@webpack-cli/webpack-scaffold";
@@ -51,7 +50,7 @@ function replaceAt(str: string, index: number, replace: string): string {
  * is present
  */
 const traverseAndGetProperties = (arr: object[], prop: string): boolean => {
-	let hasProp: boolean = false;
+	let hasProp = false;
 	arr.forEach((p: object): void => {
 		if (p[prop]) {
 			hasProp = true;
@@ -174,7 +173,7 @@ export default class AddGenerator extends Generator {
 							});
 						}
 					}
-				const temp: string = action;
+				const temp = action;
 				if (action === "resolveLoader") {
 					action = "resolve";
 				}
@@ -426,11 +425,11 @@ export default class AddGenerator extends Generator {
 							.then((p: string) => {
 								if (p) {
 									this.dependencies.push(answerToAction.actionAnswer);
-									const normalizePluginName: string = answerToAction.actionAnswer.replace(
+									const normalizePluginName = answerToAction.actionAnswer.replace(
 										"-webpack-plugin",
 										"Plugin",
 									);
-									const pluginName: string = replaceAt(
+									const pluginName = replaceAt(
 										normalizePluginName,
 										0,
 										normalizePluginName.charAt(0).toUpperCase(),
@@ -472,7 +471,7 @@ export default class AddGenerator extends Generator {
 							return;
 						}
 						// Either we are adding directly at the property, else we're in a prop.theOne scenario
-						const actionMessage: string =
+						const actionMessage =
 							isDeepProp[1] === "other"
 								? `What do you want the key on ${
 									action
@@ -518,7 +517,7 @@ export default class AddGenerator extends Generator {
 									);
 								} else {
 									// We got the schema prop, we've correctly prompted it, and can add it directly
-									this.configuration.config.item = action + "." + isDeepProp[1];
+									this.configuration.config.item = `${action}.${isDeepProp[1]}`;
 									this.configuration.config.webpackOptions[action] = {
 										[isDeepProp[1]]: deepPropAns.deepProp,
 									};

packages/generators/addon-generator.ts

@@ -46,7 +46,7 @@ export default function addonGenerator(
 		}
 
 		public default() {
-			const currentDirName: string = path.basename(this.destinationPath());
+			const currentDirName = path.basename(this.destinationPath());
 			if (currentDirName !== this.props.name) {
 				this.log(`
 				Your project must be inside a folder named ${this.props.name}

packages/generators/init-generator.ts

@@ -430,7 +430,7 @@ export default class InitGenerator extends Generator {
 	public installPlugins() {
 		if (this.isProd) {
 			this.dependencies = this.dependencies.filter(
-				(p: string) => p !== "terser-webpack-plugin",
+				(p: string): boolean => p !== "terser-webpack-plugin",
 			);
 		} else {
 			this.configuration.config.topScope.push(
@@ -439,7 +439,7 @@ export default class InitGenerator extends Generator {
 				"\n",
 			);
 		}
-		const packager: string = getPackageManager();
+		const packager = getPackageManager();
 		const opts: {
 			dev?: boolean,
 			"save-dev"?: boolean,

packages/generators/remove-generator.ts

@@ -33,8 +33,8 @@ export default class RemoveGenerator extends Generator {
 			},
 		};
 
-		let configPath: string = path.resolve(process.cwd(), "webpack.config.js");
-		const webpackConfigExists: boolean = fs.existsSync(configPath);
+		let configPath = path.resolve(process.cwd(), "webpack.config.js");
+		const webpackConfigExists = fs.existsSync(configPath);
 		if (!webpackConfigExists) {
 			configPath = null;
 			// end the generator stating webpack config not found or to specify the config

packages/generators/utils/validate.ts

@@ -7,9 +7,7 @@
  * Or a string if the user hasn't written anything
  */
 export default function validate(value: string): string | boolean {
-	const pass: number = value.length;
-
-	if (pass) {
+	if (value.length) {
 		return true;
 	}
 

packages/init/index.ts

@@ -14,7 +14,7 @@ import npmPackagesExists from "@webpack-cli/utils/npm-packages-exists";
  */
 
 export default function initializeInquirer(...args: string[]): Function | void {
-	const packages: string[] = args.slice(3);
+	const packages = args.slice(3);
 
 	if (packages.length === 0) {
 		return modifyConfigHelper("init", defaultGenerator);

packages/init/init.ts

@@ -42,11 +42,11 @@ export default function runTransform(webpackProperties: IWebpackProperties, acti
 			.keys(webpackProperties)
 			.filter((p: string): boolean => p !== "configFile" && p !== "configPath");
 
-	const initActionNotDefined: boolean = (action && action !== "init") || false;
+	const initActionNotDefined = (action && action !== "init") || false;
 
 	webpackConfig.forEach((scaffoldPiece: string): Promise<void> => {
 		const config: IConfiguration = webpackProperties[scaffoldPiece];
-		const transformations: string[] = mapOptionsToTransform(config);
+		const transformations = mapOptionsToTransform(config);
 		const ast = j(
 			initActionNotDefined
 				? webpackProperties.configFile
@@ -58,12 +58,12 @@ export default function runTransform(webpackProperties: IWebpackProperties, acti
 			return astTransform(j, ast, config.webpackOptions[f], transformAction, f);
 		})
 			.then((value: string[]): void | PromiseLike <void> => {
-				let configurationName: string = "webpack.config.js";
+				let configurationName = "webpack.config.js";
 				if (config.configName) {
-					configurationName = "webpack." + config.configName + ".js";
+					configurationName = `webpack.${config.configName}.js`;
 				}
 
-				const outputPath: string = initActionNotDefined
+				const outputPath = initActionNotDefined
 					? webpackProperties.configPath
 					: path.join(process.cwd(), configurationName);
 

packages/migrate/index.ts

@@ -42,14 +42,14 @@ declare var process: {
  */
 
 export default function migrate(...args: string[]): void | Promise<void> {
-	const filePaths: string[] = args.slice(3);
+	const filePaths = args.slice(3);
 	if (!filePaths.length) {
-		const errMsg: string = "\n ✖ Please specify a path to your webpack config \n ";
+		const errMsg = "\n ✖ Please specify a path to your webpack config \n ";
 		console.error(chalk.red(errMsg));
 		return;
 	}
 
-	const currentConfigPath: string = path.resolve(process.cwd(), filePaths[0]);
+	const currentConfigPath = path.resolve(process.cwd(), filePaths[0]);
 	let outputConfigPath: string;
 
 	if (!filePaths[1]) {
@@ -232,7 +232,7 @@ function runMigration(currentConfigPath: string, outputConfigPath: string): Prom
 				});
 		})
 		.catch((err: object): void => {
-			const errMsg: string = "\n ✖ ︎Migration aborted due to some errors: \n";
+			const errMsg = "\n ✖ ︎Migration aborted due to some errors: \n";
 			console.error(chalk.red(errMsg));
 			console.error(err);
 			process.exitCode = 1;

packages/remove/index.ts

@@ -11,10 +11,10 @@ import modifyConfigHelper from "@webpack-cli/utils/modify-config-helper";
  */
 
 export default function remove(...args: string[]): Function {
-	const DEFAULT_WEBPACK_CONFIG_FILENAME: string = "webpack.config.js";
+	const DEFAULT_WEBPACK_CONFIG_FILENAME = "webpack.config.js";
 
-	const filePaths: string[] = args.slice(3);
-	let configFile: string = DEFAULT_WEBPACK_CONFIG_FILENAME;
+	const filePaths = args.slice(3);
+	let configFile = DEFAULT_WEBPACK_CONFIG_FILENAME;
 	if (filePaths.length) {
 		configFile = filePaths[0];
 	}

packages/serve/index.ts

@@ -52,7 +52,7 @@ const getRootPathModule = (dep: string): string => path.resolve(process.cwd(), d
  */
 
 function serve() {
-	const packageJSONPath: string = getRootPathModule("package.json");
+	const packageJSONPath = getRootPathModule("package.json");
 	if (!packageJSONPath) {
 		console.error(
 			"\n",

packages/update/index.ts

@@ -11,10 +11,10 @@ import modifyConfigHelper from "@webpack-cli/utils/modify-config-helper";
  */
 
 export default function update(...args: string[]): Function {
-	const DEFAULT_WEBPACK_CONFIG_FILENAME: string = "webpack.config.js";
+	const DEFAULT_WEBPACK_CONFIG_FILENAME = "webpack.config.js";
 
-	const filePaths: string[] = args.slice(3);
-	let configFile: string = DEFAULT_WEBPACK_CONFIG_FILENAME;
+	const filePaths = args.slice(3);
+	let configFile = DEFAULT_WEBPACK_CONFIG_FILENAME;
 	if (filePaths.length) {
 		configFile = filePaths[0];
 	}

packages/utils/ast-utils.ts

@@ -8,9 +8,10 @@ import * as validateIdentifier from "./validate-identifier";
  * @param {Array} paths - Array of strings containing the traversal path
  * @returns {Any} Value at given traversal path
  */
+
 function safeTraverse(obj: INode, paths: string[]): any {
 	let val: INode = obj;
-	let idx: number = 0;
+	let idx = 0;
 
 	while (idx < paths.length) {
 		if (!val) {
@@ -28,13 +29,19 @@ function safeTraverse(obj: INode, paths: string[]): any {
  * @param {Node} path - AST node
  * @returns {String|Boolean} type at given path.
  */
+
 function safeTraverseAndGetType(path: INode): string | boolean {
 	const pathValue: INode = safeTraverse(path, ["value", "value"]);
 	return pathValue ? pathValue.type : false;
 }
 
-// Convert nested MemberExpressions to strings like webpack.optimize.DedupePlugin
-function memberExpressionToPathString(path: INode) {
+/**
+ * Convert nested MemberExpressions to strings like webpack.optimize.DedupePlugin
+ * @param {Node} path - AST node
+ * @returns {String} member expression string.
+ */
+
+function memberExpressionToPathString(path: INode): string {
 	if (path && path.object) {
 		return [memberExpressionToPathString(path.object), path.property.name].join(
 			".",
@@ -230,7 +237,7 @@ function addOrUpdateConfigObject(
 
 	if (propertyExists) {
 		rootNode.properties
-			.filter((path: INode) => path.key.name === configProperty)
+			.filter((path: INode): boolean => path.key.name === configProperty)
 			.forEach((path: INode) => {
 				const newProperties = path.value.properties.filter(
 					(p: INode) => p.key.name !== key,
@@ -269,7 +276,7 @@ function findAndRemovePluginByName(j: IJSCodeshift, node: INode, pluginName: str
 	let rootPath: INode;
 
 	findPluginsByName(j, node, [pluginName])
-		.filter((path: INode) => safeTraverse(path, ["parent", "value"]))
+		.filter((path: INode): boolean => safeTraverse(path, ["parent", "value"]))
 		.forEach((path: INode) => {
 			rootPath = safeTraverse(path, ["parent", "parent", "parent", "value"]);
 			const arrayPath: INode = path.parent.value;
@@ -324,7 +331,7 @@ function createOrUpdatePluginByName(j: IJSCodeshift, rootNodePath: INode, plugin
 						// Search for same keys in the existing object
 						const existingProps = j(currentProps)
 							.find(j.Identifier)
-							.filter((p: INode) => opt.key.value === p.value.name);
+							.filter((p: INode): boolean => opt.key.value === p.value.name);
 
 						if (existingProps.size()) {
 							// Replacing values for the same key

packages/utils/copy-utils.ts

@@ -20,9 +20,9 @@ export const generatorCopy = (
 	generator,
 	templateDir: string,
 ): (filePath: string) => void => (filePath: string): void => {
-	const sourceParts: string[] = templateDir.split(path.delimiter);
+	const sourceParts = templateDir.split(path.delimiter);
 	sourceParts.push.apply(sourceParts, filePath.split("/"));
-	const targetParts: string[] = path.dirname(filePath).split("/");
+	const targetParts = path.dirname(filePath).split("/");
 	targetParts.push(path.basename(filePath, ".tpl"));
 
 	generator.fs.copy(
@@ -47,9 +47,9 @@ export const generatorCopyTpl = (
 	templateDir: string,
 	templateData: object,
 ): (filePath: string) => void => (filePath: string): void => {
-	const sourceParts: string[] = templateDir.split(path.delimiter);
+	const sourceParts = templateDir.split(path.delimiter);
 	sourceParts.push.apply(sourceParts, filePath.split("/"));
-	const targetParts: string[] = path.dirname(filePath).split("/");
+	const targetParts = path.dirname(filePath).split("/");
 	targetParts.push(path.basename(filePath, ".tpl").slice(1));
 
 	generator.fs.copyTpl(