// Type definitions for yargs 13.0
// Project: https://github.com/chevex/yargs, https://yargs.js.org
// Definitions by: Martin Poelstra <https://github.com/poelstra>
//                 Mizunashi Mana <https://github.com/mizunashi-mana>
//                 Jeffery Grajkowski <https://github.com/pushplay>
//                 Jeff Kenney <https://github.com/jeffkenney>
//                 Jimi (Dimitris) Charalampidis <https://github.com/JimiC>
//                 Steffen Viken Valvåg <https://github.com/steffenvv>
//                 Emily Marigold Klassen <https://github.com/forivall>
//                 ExE Boss <https://github.com/ExE-Boss>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
// TypeScript Version: 3.0

// The following TSLint rules have been disabled:
// unified-signatures: Because there is useful information in the argument names of the overloaded signatures

// Convention:
// Use 'union types' when:
//  - parameter types have similar signature type (i.e. 'string | ReadonlyArray<string>')
//  - parameter names have the same semantic meaning (i.e. ['command', 'commands'] , ['key', 'keys'])
//    An example for not using 'union types' is the declaration of 'env' where `prefix` and `enable` parameters
//    have different semantics. On the other hand, in the declaration of 'usage', a `command: string` parameter
//    has the same semantic meaning with declaring an overload method by using `commands: ReadonlyArray<string>`,
//    thus it's preferred to use `command: string | ReadonlyArray<string>`
// Use parameterless declaration instead of declaring all parameters optional,
// when all parameters are optional and more than one

import { DetailedArguments, Configuration } from 'yargs-parser';

declare namespace yargs {
    type BuilderCallback<T, R> = ((args: Argv<T>) => Argv<R>) | ((args: Argv<T>) => void);

    type ParserConfigurationOptions = Configuration & {
        /** Sort commands alphabetically. Default is `false` */
        'sort-commands': boolean;
    };

    /**
     * The type parameter `T` is the expected shape of the parsed options.
     * `Arguments<T>` is those options plus `_` and `$0`, and an indexer falling
     * back to `unknown` for unknown options.
     *
     * For the return type / `argv` property, we create a mapped type over
     * `Arguments<T>` to simplify the inferred type signature in client code.
     */
    interface Argv<T = {}> {
        (): { [key in keyof Arguments<T>]: Arguments<T>[key] };
        (args: ReadonlyArray<string>, cwd?: string): Argv<T>;

        /**
         * Set key names as equivalent such that updates to a key will propagate to aliases and vice-versa.
         *
         * Optionally `.alias()` can take an object that maps keys to aliases.
         * Each key of this object should be the canonical version of the option, and each value should be a string or an array of strings.
         */
        // Aliases for previously declared options can inherit the types of those options.
        alias<K1 extends keyof T, K2 extends string>(shortName: K1, longName: K2 | ReadonlyArray<K2>): Argv<T & { [key in K2]: T[K1] }>;
        alias<K1 extends keyof T, K2 extends string>(shortName: K2, longName: K1 | ReadonlyArray<K1>): Argv<T & { [key in K2]: T[K1] }>;
        alias(shortName: string | ReadonlyArray<string>, longName: string | ReadonlyArray<string>): Argv<T>;
        alias(aliases: { [shortName: string]: string | ReadonlyArray<string> }): Argv<T>;

        /**
         * Get the arguments as a plain old object.
         *
         * Arguments without a corresponding flag show up in the `argv._` array.
         *
         * The script name or node command is available at `argv.$0` similarly to how `$0` works in bash or perl.
         *
         * If `yargs` is executed in an environment that embeds node and there's no script name (e.g. Electron or nw.js),
         * it will ignore the first parameter since it expects it to be the script name. In order to override
         * this behavior, use `.parse(process.argv.slice(1))` instead of .argv and the first parameter won't be ignored.
         */
        argv: { [key in keyof Arguments<T>]: Arguments<T>[key] };

        /**
         * Tell the parser to interpret `key` as an array.
         * If `.array('foo')` is set, `--foo foo bar` will be parsed as `['foo', 'bar']` rather than as `'foo'`.
         * Also, if you use the option multiple times all the values will be flattened in one array so `--foo foo --foo bar` will be parsed as `['foo', 'bar']`
         *
         * When the option is used with a positional, use `--` to tell `yargs` to stop adding values to the array.
         */
        array<K extends keyof T>(key: K | ReadonlyArray<K>): Argv<Omit<T, K> & { [key in K]: ToArray<T[key]> }>;
        array<K extends string>(key: K | ReadonlyArray<K>): Argv<T & { [key in K]: Array<string | number> | undefined }>;

        /**
         * Interpret `key` as a boolean. If a non-flag option follows `key` in `process.argv`, that string won't get set as the value of `key`.
         *
         * `key` will default to `false`, unless a `default(key, undefined)` is explicitly set.
         *
         * If `key` is an array, interpret all the elements as booleans.
         */
        boolean<K extends keyof T>(key: K | ReadonlyArray<K>): Argv<Omit<T, K> & { [key in K]: boolean | undefined }>;
        boolean<K extends string>(key: K | ReadonlyArray<K>): Argv<T & { [key in K]: boolean | undefined }>;

        /**
         * Check that certain conditions are met in the provided arguments.
         * @param func Called with two arguments, the parsed `argv` hash and an array of options and their aliases.
         * If `func` throws or returns a non-truthy value, show the thrown error, usage information, and exit.
         * @param global Indicates whether `check()` should be enabled both at the top-level and for each sub-command.
         */
        check(func: (argv: Arguments<T>, aliases: { [alias: string]: string }) => any, global?: boolean): Argv<T>;

        /**
         * Limit valid values for key to a predefined set of choices, given as an array or as an individual value.
         * If this method is called multiple times, all enumerated values will be merged together.
         * Choices are generally strings or numbers, and value matching is case-sensitive.
         *
         * Optionally `.choices()` can take an object that maps multiple keys to their choices.
         *
         * Choices can also be specified as choices in the object given to `option()`.
         */
        choices<K extends keyof T, C extends ReadonlyArray<any>>(key: K, values: C): Argv<Omit<T, K> & { [key in K]: C[number] | undefined }>;
        choices<K extends string, C extends ReadonlyArray<any>>(key: K, values: C): Argv<T & { [key in K]: C[number] | undefined }>;
        choices<C extends { [key: string]: ReadonlyArray<any> }>(choices: C): Argv<Omit<T, keyof C> & { [key in keyof C]: C[key][number] | undefined }>;

        /**
         * Provide a synchronous function to coerce or transform the value(s) given on the command line for `key`.
         *
         * The coercion function should accept one argument, representing the parsed value from the command line, and should return a new value or throw an error.
         * The returned value will be used as the value for `key` (or one of its aliases) in `argv`.
         *
         * If the function throws, the error will be treated as a validation failure, delegating to either a custom `.fail()` handler or printing the error message in the console.
         *
         * Coercion will be applied to a value after all other modifications, such as `.normalize()`.
         *
         * Optionally `.coerce()` can take an object that maps several keys to their respective coercion function.
         *
         * You can also map the same function to several keys at one time. Just pass an array of keys as the first argument to `.coerce()`.
         *
         * If you are using dot-notion or arrays, .e.g., `user.email` and `user.password`, coercion will be applied to the final object that has been parsed
         */
        coerce<K extends keyof T, V>(key: K | ReadonlyArray<K>, func: (arg: any) => V): Argv<Omit<T, K> & { [key in K]: V | undefined }>;
        coerce<K extends string, V>(key: K | ReadonlyArray<K>, func: (arg: any) => V): Argv<T & { [key in K]: V | undefined }>;
        coerce<O extends { [key: string]: (arg: any) => any }>(opts: O): Argv<Omit<T, keyof O> & { [key in keyof O]: ReturnType<O[key]> | undefined }>;

        /**
         * Define the commands exposed by your application.
         * @param command Should be a string representing the command or an array of strings representing the command and its aliases.
         * @param description Use to provide a description for each command your application accepts (the values stored in `argv._`).
         * Set `description` to false to create a hidden command. Hidden commands don't show up in the help output and aren't available for completion.
         * @param [builder] Object to give hints about the options that your command accepts.
         * Can also be a function. This function is executed with a yargs instance, and can be used to provide advanced command specific help.
         *
         * Note that when `void` is returned, the handler `argv` object type will not include command-specific arguments.
         * @param [handler] Function, which will be executed with the parsed `argv` object.
         */
        command<U = T>(command: string | ReadonlyArray<string>, description: string, builder?: BuilderCallback<T, U>, handler?: (args: Arguments<U>) => void): Argv<T>;
        command<O extends { [key: string]: Options }>(command: string | ReadonlyArray<string>, description: string, builder?: O, handler?: (args: Arguments<InferredOptionTypes<O>>) => void): Argv<T>;
        command<U>(command: string | ReadonlyArray<string>, description: string, module: CommandModule<T, U>): Argv<U>;
        command<U = T>(command: string | ReadonlyArray<string>, showInHelp: false, builder?: BuilderCallback<T, U>, handler?: (args: Arguments<U>) => void): Argv<T>;
        command<O extends { [key: string]: Options }>(command: string | ReadonlyArray<string>, showInHelp: false, builder?: O, handler?: (args: Arguments<InferredOptionTypes<O>>) => void): Argv<T>;
        command<U>(command: string | ReadonlyArray<string>, showInHelp: false, module: CommandModule<T, U>): Argv<U>;
        command<U>(module: CommandModule<T, U>): Argv<U>;

        // Advanced API
        /** Apply command modules from a directory relative to the module calling this method. */
        commandDir(dir: string, opts?: RequireDirectoryOptions): Argv<T>;

        /**
         * Enable bash/zsh-completion shortcuts for commands and options.
         *
         * If invoked without parameters, `.completion()` will make completion the command to output the completion script.
         *
         * @param [cmd] When present in `argv._`, will result in the `.bashrc` or `.zshrc` completion script being outputted.
         * To enable bash/zsh completions, concat the generated script to your `.bashrc` or `.bash_profile` (or `.zshrc` for zsh).
         * @param [description] Provide a description in your usage instructions for the command that generates the completion scripts.
         * @param [func] Rather than relying on yargs' default completion functionality, which shiver me timbers is pretty awesome, you can provide your own completion method.
         */
        completion(): Argv<T>;
        completion(cmd: string, func?: AsyncCompletionFunction): Argv<T>;
        completion(cmd: string, func?: SyncCompletionFunction): Argv<T>;
        completion(cmd: string, func?: PromiseCompletionFunction): Argv<T>;
        completion(cmd: string, description?: string | false, func?: AsyncCompletionFunction): Argv<T>;
        completion(cmd: string, description?: string | false, func?: SyncCompletionFunction): Argv<T>;
        completion(cmd: string, description?: string | false, func?: PromiseCompletionFunction): Argv<T>;

        /**
         * Tells the parser that if the option specified by `key` is passed in, it should be interpreted as a path to a JSON config file.
         * The file is loaded and parsed, and its properties are set as arguments.
         * Because the file is loaded using Node's require(), the filename MUST end in `.json` to be interpreted correctly.
         *
         * If invoked without parameters, `.config()` will make --config the option to pass the JSON config file.
         *
         * @param [description] Provided to customize the config (`key`) option in the usage string.
         * @param [explicitConfigurationObject] An explicit configuration `object`
         */
        config(): Argv<T>;
        config(key: string | ReadonlyArray<string>, description?: string, parseFn?: (configPath: string) => object): Argv<T>;
        config(key: string | ReadonlyArray<string>, parseFn: (configPath: string) => object): Argv<T>;
        config(explicitConfigurationObject: object): Argv<T>;

        /**
         * Given the key `x` is set, the key `y` must not be set. `y` can either be a single string or an array of argument names that `x` conflicts with.
         *
         * Optionally `.conflicts()` can accept an object specifying multiple conflicting keys.
         */
        conflicts(key: string, value: string | ReadonlyArray<string>): Argv<T>;
        conflicts(conflicts: { [key: string]: string | ReadonlyArray<string> }): Argv<T>;

        /**
         * Interpret `key` as a boolean flag, but set its parsed value to the number of flag occurrences rather than `true` or `false`. Default value is thus `0`.
         */
        count<K extends keyof T>(key: K | ReadonlyArray<K>): Argv<Omit<T, K> & { [key in K]: number }>;
        count<K extends string>(key: K | ReadonlyArray<K>): Argv<T & { [key in K]: number }>;

        /**
         * Set `argv[key]` to `value` if no option was specified in `process.argv`.
         *
         * Optionally `.default()` can take an object that maps keys to default values.
         *
         * The default value can be a `function` which returns a value. The name of the function will be used in the usage string.
         *
         * Optionally, `description` can also be provided and will take precedence over displaying the value in the usage instructions.
         */
        default<K extends keyof T, V>(key: K, value: V, description?: string): Argv<Omit<T, K> & { [key in K]: V }>;
        default<K extends string, V>(key: K, value: V, description?: string): Argv<T & { [key in K]: V }>;
        default<D extends { [key: string]: any }>(defaults: D, description?: string): Argv<Omit<T, keyof D> & D>;

        /**
         * @deprecated since version 6.6.0
         * Use '.demandCommand()' or '.demandOption()' instead
         */
        demand<K extends keyof T>(key: K | ReadonlyArray<K>, msg?: string | true): Argv<Defined<T, K>>;
        demand<K extends string>(key: K | ReadonlyArray<K>, msg?: string | true): Argv<T & { [key in K]: unknown }>;
        demand(key: string | ReadonlyArray<string>, required?: boolean): Argv<T>;
        demand(positionals: number, msg: string): Argv<T>;
        demand(positionals: number, required?: boolean): Argv<T>;
        demand(positionals: number, max: number, msg?: string): Argv<T>;

        /**
         * @param key If is a string, show the usage information and exit if key wasn't specified in `process.argv`.
         * If is an array, demand each element.
         * @param msg If string is given, it will be printed when the argument is missing, instead of the standard error message.
         * @param demand Controls whether the option is demanded; this is useful when using .options() to specify command line parameters.
         */
        demandOption<K extends keyof T>(key: K | ReadonlyArray<K>, msg?: string | true): Argv<Defined<T, K>>;
        demandOption<K extends string>(key: K | ReadonlyArray<K>, msg?: string | true): Argv<T & { [key in K]: unknown }>;
        demandOption(key: string | ReadonlyArray<string>, demand?: boolean): Argv<T>;

        /**
         * Demand in context of commands.
         * You can demand a minimum and a maximum number a user can have within your program, as well as provide corresponding error messages if either of the demands is not met.
         */
        demandCommand(): Argv<T>;
        demandCommand(min: number, minMsg?: string): Argv<T>;
        demandCommand(min: number, max?: number, minMsg?: string, maxMsg?: string): Argv<T>;

        /**
         * Describe a `key` for the generated usage information.
         *
         * Optionally `.describe()` can take an object that maps keys to descriptions.
         */
        describe(key: string | ReadonlyArray<string>, description: string): Argv<T>;
        describe(descriptions: { [key: string]: string }): Argv<T>;

        /** Should yargs attempt to detect the os' locale? Defaults to `true`. */
        detectLocale(detect: boolean): Argv<T>;

        /**
         * Tell yargs to parse environment variables matching the given prefix and apply them to argv as though they were command line arguments.
         *
         * Use the "__" separator in the environment variable to indicate nested options. (e.g. prefix_nested__foo => nested.foo)
         *
         * If this method is called with no argument or with an empty string or with true, then all env vars will be applied to argv.
         *
         * Program arguments are defined in this order of precedence:
         * 1. Command line args
         * 2. Env vars
         * 3. Config file/objects
         * 4. Configured defaults
         *
         * Env var parsing is disabled by default, but you can also explicitly disable it by calling `.env(false)`, e.g. if you need to undo previous configuration.
         */
        env(): Argv<T>;
        env(prefix: string): Argv<T>;
        env(enable: boolean): Argv<T>;

        /** A message to print at the end of the usage instructions */
        epilog(msg: string): Argv<T>;
        /** A message to print at the end of the usage instructions */
        epilogue(msg: string): Argv<T>;

        /**
         * Give some example invocations of your program.
         * Inside `cmd`, the string `$0` will get interpolated to the current script name or node command for the present script similar to how `$0` works in bash or perl.
         * Examples will be printed out as part of the help message.
         */
        example(command: string, description: string): Argv<T>;

        /** Manually indicate that the program should exit, and provide context about why we wanted to exit. Follows the behavior set by `.exitProcess().` */
        exit(code: number, err: Error): void;

        /**
         * By default, yargs exits the process when the user passes a help flag, the user uses the `.version` functionality, validation fails, or the command handler fails.
         * Calling `.exitProcess(false)` disables this behavior, enabling further actions after yargs have been validated.
         */
        exitProcess(enabled: boolean): Argv<T>;

        /**
         * Method to execute when a failure occurs, rather than printing the failure message.
         * @param func Is called with the failure message that would have been printed, the Error instance originally thrown and yargs state when the failure occurred.
         */
        fail(func: (msg: string, err: Error, yargs: Argv<T>) => any): Argv<T>;

        /**
         * Allows to programmatically get completion choices for any line.
         * @param args An array of the words in the command line to complete.
         * @param done The callback to be called with the resulting completions.
         */
        getCompletion(args: ReadonlyArray<string>, done: (completions: ReadonlyArray<string>) => void): Argv<T>;

        /**
         * Indicate that an option (or group of options) should not be reset when a command is executed
         *
         * Options default to being global.
         */
        global(key: string | ReadonlyArray<string>): Argv<T>;

        /** Given a key, or an array of keys, places options under an alternative heading when displaying usage instructions */
        group(key: string | ReadonlyArray<string>, groupName: string): Argv<T>;

        /** Hides a key from the generated usage information. Unless a `--show-hidden` option is also passed with `--help` (see `showHidden()`). */
        hide(key: string): Argv<T>;

        /**
         * Configure an (e.g. `--help`) and implicit command that displays the usage string and exits the process.
         * By default yargs enables help on the `--help` option.
         *
         * Note that any multi-char aliases (e.g. `help`) used for the help option will also be used for the implicit command.
         * If there are no multi-char aliases (e.g. `h`), then all single-char aliases will be used for the command.
         *
         * If invoked without parameters, `.help()` will use `--help` as the option and help as the implicit command to trigger help output.
         *
         * @param [description] Customizes the description of the help option in the usage string.
         * @param [enableExplicit] If `false` is provided, it will disable --help.
         */
        help(): Argv<T>;
        help(enableExplicit: boolean): Argv<T>;
        help(option: string, enableExplicit: boolean): Argv<T>;
        help(option: string, description?: string, enableExplicit?: boolean): Argv<T>;

        /**
         * Given the key `x` is set, it is required that the key `y` is set.
         * y` can either be the name of an argument to imply, a number indicating the position of an argument or an array of multiple implications to associate with `x`.
         *
         * Optionally `.implies()` can accept an object specifying multiple implications.
         */
        implies(key: string, value: string | ReadonlyArray<string>): Argv<T>;
        implies(implies: { [key: string]: string | ReadonlyArray<string> }): Argv<T>;

        /**
         * Return the locale that yargs is currently using.
         *
         * By default, yargs will auto-detect the operating system's locale so that yargs-generated help content will display in the user's language.
         */
        locale(): string;
        /**
         * Override the auto-detected locale from the user's operating system with a static locale.
         * Note that the OS locale can be modified by setting/exporting the `LC_ALL` environment variable.
         */
        locale(loc: string): Argv<T>;

        /**
         * Define global middleware functions to be called first, in list order, for all cli command.
         * @param callbacks Can be a function or a list of functions. Each callback gets passed a reference to argv.
         * @param [applyBeforeValidation] Set to `true` to apply middleware before validation. This will execute the middleware prior to validation checks, but after parsing.
         */
        middleware(callbacks: MiddlewareFunction<T> | ReadonlyArray<MiddlewareFunction<T>>, applyBeforeValidation?: boolean): Argv<T>;

        /**
         * The number of arguments that should be consumed after a key. This can be a useful hint to prevent parsing ambiguity.
         *
         * Optionally `.nargs()` can take an object of `key`/`narg` pairs.
         */
        nargs(key: string, count: number): Argv<T>;
        nargs(nargs: { [key: string]: number }): Argv<T>;

        /** The key provided represents a path and should have `path.normalize()` applied. */
        normalize<K extends keyof T>(key: K | ReadonlyArray<K>): Argv<Omit<T, K> & { [key in K]: ToString<T[key]> }>;
        normalize<K extends string>(key: K | ReadonlyArray<K>): Argv<T & { [key in K]: string | undefined }>;

        /**
         * Tell the parser to always interpret key as a number.
         *
         * If `key` is an array, all elements will be parsed as numbers.
         *
         * If the option is given on the command line without a value, `argv` will be populated with `undefined`.
         *
         * If the value given on the command line cannot be parsed as a number, `argv` will be populated with `NaN`.
         *
         * Note that decimals, hexadecimals, and scientific notation are all accepted.
         */
        number<K extends keyof T>(key: K | ReadonlyArray<K>): Argv<Omit<T, K> & { [key in K]: ToNumber<T[key]> }>;
        number<K extends string>(key: K | ReadonlyArray<K>): Argv<T & { [key in K]: number | undefined }>;

        /**
         * This method can be used to make yargs aware of options that could exist.
         * You can also pass an opt object which can hold further customization, like `.alias()`, `.demandOption()` etc. for that option.
         */
        option<K extends keyof T, O extends Options>(key: K, options: O): Argv<Omit<T, K> & { [key in K]: InferredOptionType<O> }>;
        option<K extends string, O extends Options>(key: K, options: O): Argv<T & { [key in K]: InferredOptionType<O> }>;
        option<O extends { [key: string]: Options }>(options: O): Argv<Omit<T, keyof O> & InferredOptionTypes<O>>;

        /**
         * This method can be used to make yargs aware of options that could exist.
         * You can also pass an opt object which can hold further customization, like `.alias()`, `.demandOption()` etc. for that option.
         */
        options<K extends keyof T, O extends Options>(key: K, options: O): Argv<Omit<T, K> & { [key in K]: InferredOptionType<O> }>;
        options<K extends string, O extends Options>(key: K, options: O): Argv<T & { [key in K]: InferredOptionType<O> }>;
        options<O extends { [key: string]: Options }>(options: O): Argv<Omit<T, keyof O> & InferredOptionTypes<O>>;

        /**
         * Parse `args` instead of `process.argv`. Returns the `argv` object. `args` may either be a pre-processed argv array, or a raw argument string.
         *
         * Note: Providing a callback to parse() disables the `exitProcess` setting until after the callback is invoked.
         * @param [context]  Provides a useful mechanism for passing state information to commands
         */
        parse(): { [key in keyof Arguments<T>]: Arguments<T>[key] };
        parse(arg: string | ReadonlyArray<string>, context?: object, parseCallback?: ParseCallback<T>): { [key in keyof Arguments<T>]: Arguments<T>[key] };

        /**
         * If the arguments have not been parsed, this property is `false`.
         *
         * If the arguments have been parsed, this contain detailed parsed arguments.
         */
        parsed: DetailedArguments | false;

        /** Allows to configure advanced yargs features. */
        parserConfiguration(configuration: Partial<ParserConfigurationOptions>): Argv<T>;

        /**
         * Similar to `config()`, indicates that yargs should interpret the object from the specified key in package.json as a configuration object.
         * @param [cwd] If provided, the package.json will be read from this location
         */
        pkgConf(key: string | ReadonlyArray<string>, cwd?: string): Argv<T>;

        /**
         * Allows you to configure a command's positional arguments with an API similar to `.option()`.
         * `.positional()` should be called in a command's builder function, and is not available on the top-level yargs instance. If so, it will throw an error.
         */
        positional<K extends keyof T, O extends PositionalOptions>(key: K, opt: O): Argv<Omit<T, K> & { [key in K]: InferredOptionType<O> }>;
        positional<K extends string, O extends PositionalOptions>(key: K, opt: O): Argv<T & { [key in K]: InferredOptionType<O> }>;

        /** Should yargs provide suggestions regarding similar commands if no matching command is found? */
        recommendCommands(): Argv<T>;

        /**
         * @deprecated since version 6.6.0
         * Use '.demandCommand()' or '.demandOption()' instead
         */
        require<K extends keyof T>(key: K | ReadonlyArray<K>, msg?: string | true): Argv<Defined<T, K>>;
        require(key: string, msg: string): Argv<T>;
        require(key: string, required: boolean): Argv<T>;
        require(keys: ReadonlyArray<number>, msg: string): Argv<T>;
        require(keys: ReadonlyArray<number>, required: boolean): Argv<T>;
        require(positionals: number, required: boolean): Argv<T>;
        require(positionals: number, msg: string): Argv<T>;

        /**
         * @deprecated since version 6.6.0
         * Use '.demandCommand()' or '.demandOption()' instead
         */
        required<K extends keyof T>(key: K | ReadonlyArray<K>, msg?: string | true): Argv<Defined<T, K>>;
        required(key: string, msg: string): Argv<T>;
        required(key: string, required: boolean): Argv<T>;
        required(keys: ReadonlyArray<number>, msg: string): Argv<T>;
        required(keys: ReadonlyArray<number>, required: boolean): Argv<T>;
        required(positionals: number, required: boolean): Argv<T>;
        required(positionals: number, msg: string): Argv<T>;

        requiresArg(key: string | ReadonlyArray<string>): Argv<T>;

        /**
         * @deprecated since version 6.6.0
         * Use '.global()' instead
         */
        reset(): Argv<T>;

        /** Set the name of your script ($0). Default is the base filename executed by node (`process.argv[1]`) */
        scriptName($0: string): Argv<T>;

        /**
         * Generate a bash completion script.
         * Users of your application can install this script in their `.bashrc`, and yargs will provide completion shortcuts for commands and options.
         */
        showCompletionScript(): Argv<T>;

        /**
         * Configure the `--show-hidden` option that displays the hidden keys (see `hide()`).
         * @param option If `boolean`, it enables/disables this option altogether. i.e. hidden keys will be permanently hidden if first argument is `false`.
         * If `string` it changes the key name ("--show-hidden").
         * @param description Changes the default description ("Show hidden options")
         */
        showHidden(option?: string | boolean): Argv<T>;
        showHidden(option: string, description?: string): Argv<T>;

        /**
         * Print the usage data using the console function consoleLevel for printing.
         * @param [consoleLevel='error']
         */
        showHelp(consoleLevel?: string): Argv<T>;

        /**
         * By default, yargs outputs a usage string if any error is detected.
         * Use the `.showHelpOnFail()` method to customize this behavior.
         * @param enable If `false`, the usage string is not output.
         * @param [message] Message that is output after the error message.
         */
        showHelpOnFail(enable: boolean, message?: string): Argv<T>;

        /** Specifies either a single option key (string), or an array of options. If any of the options is present, yargs validation is skipped. */
        skipValidation(key: string | ReadonlyArray<string>): Argv<T>;

        /**
         * Any command-line argument given that is not demanded, or does not have a corresponding description, will be reported as an error.
         *
         * Unrecognized commands will also be reported as errors.
         */
        strict(): Argv<T>;
        strict(enabled: boolean): Argv<T>;

        /**
         * Tell the parser logic not to interpret `key` as a number or boolean. This can be useful if you need to preserve leading zeros in an input.
         *
         * If `key` is an array, interpret all the elements as strings.
         *
         * `.string('_')` will result in non-hyphenated arguments being interpreted as strings, regardless of whether they resemble numbers.
         */
        string<K extends keyof T>(key: K | ReadonlyArray<K>): Argv<Omit<T, K> & { [key in K]: ToString<T[key]> }>;
        string<K extends string>(key: K | ReadonlyArray<K>): Argv<T & { [key in K]: string | undefined }>;

        // Intended to be used with '.wrap()'
        terminalWidth(): number;

        updateLocale(obj: { [key: string]: string }): Argv<T>;

        /**
         * Override the default strings used by yargs with the key/value pairs provided in obj
         *
         * If you explicitly specify a locale(), you should do so before calling `updateStrings()`.
         */
        updateStrings(obj: { [key: string]: string }): Argv<T>;

        /**
         * Set a usage message to show which commands to use.
         * Inside `message`, the string `$0` will get interpolated to the current script name or node command for the present script similar to how `$0` works in bash or perl.
         *
         * If the optional `description`/`builder`/`handler` are provided, `.usage()` acts an an alias for `.command()`.
         * This allows you to use `.usage()` to configure the default command that will be run as an entry-point to your application
         * and allows you to provide configuration for the positional arguments accepted by your program:
         */
        usage(message: string): Argv<T>;
        usage<U>(command: string | ReadonlyArray<string>, description: string, builder?: (args: Argv<T>) => Argv<U>, handler?: (args: Arguments<U>) => void): Argv<T>;
        usage<U>(command: string | ReadonlyArray<string>, showInHelp: boolean, builder?: (args: Argv<T>) => Argv<U>, handler?: (args: Arguments<U>) => void): Argv<T>;
        usage<O extends { [key: string]: Options }>(command: string | ReadonlyArray<string>, description: string, builder?: O, handler?: (args: Arguments<InferredOptionTypes<O>>) => void): Argv<T>;
        usage<O extends { [key: string]: Options }>(command: string | ReadonlyArray<string>, showInHelp: boolean, builder?: O, handler?: (args: Arguments<InferredOptionTypes<O>>) => void): Argv<T>;

        /**
         * Add an option (e.g. `--version`) that displays the version number (given by the version parameter) and exits the process.
         * By default yargs enables version for the `--version` option.
         *
         * If no arguments are passed to version (`.version()`), yargs will parse the package.json of your module and use its version value.
         *
         * If the boolean argument `false` is provided, it will disable `--version`.
         */
        version(): Argv<T>;
        version(version: string): Argv<T>;
        version(enable: boolean): Argv<T>;
        version(optionKey: string, version: string): Argv<T>;
        version(optionKey: string, description: string, version: string): Argv<T>;

        /**
         * Format usage output to wrap at columns many columns.
         *
         * By default wrap will be set to `Math.min(80, windowWidth)`. Use `.wrap(null)` to specify no column limit (no right-align).
         * Use `.wrap(yargs.terminalWidth())` to maximize the width of yargs' usage instructions.
         */
        wrap(columns: number | null): Argv<T>;
    }

    type Arguments<T = {}> = T & {
        /** Non-option arguments */
        _: string[];
        /** The script name or node command */
        $0: string;
        /** All remaining options */
        [argName: string]: unknown;
    };

    interface RequireDirectoryOptions {
        /** Look for command modules in all subdirectories and apply them as a flattened (non-hierarchical) list. */
        recurse?: boolean;
        /** The types of files to look for when requiring command modules. */
        extensions?: ReadonlyArray<string>;
        /**
         * A synchronous function called for each command module encountered.
         * Accepts `commandObject`, `pathToFile`, and `filename` as arguments.
         * Returns `commandObject` to include the command; any falsy value to exclude/skip it.
         */
        visit?: (commandObject: any, pathToFile?: string, filename?: string) => any;
        /** Whitelist certain modules */
        include?: RegExp | ((pathToFile: string) => boolean);
        /** Blacklist certain modules. */
        exclude?: RegExp | ((pathToFile: string) => boolean);
    }

    interface Options {
        /** string or array of strings, alias(es) for the canonical option key, see `alias()` */
        alias?: string | ReadonlyArray<string>;
        /** boolean, interpret option as an array, see `array()` */
        array?: boolean;
        /**  boolean, interpret option as a boolean flag, see `boolean()` */
        boolean?: boolean;
        /** value or array of values, limit valid option arguments to a predefined set, see `choices()` */
        choices?: Choices;
        /** function, coerce or transform parsed command line values into another value, see `coerce()` */
        coerce?: (arg: any) => any;
        /** boolean, interpret option as a path to a JSON config file, see `config()` */
        config?: boolean;
        /** function, provide a custom config parsing function, see `config()` */
        configParser?: (configPath: string) => object;
        /** string or object, require certain keys not to be set, see `conflicts()` */
        conflicts?: string | ReadonlyArray<string> | { [key: string]: string | ReadonlyArray<string> };
        /** boolean, interpret option as a count of boolean flags, see `count()` */
        count?: boolean;
        /** value, set a default value for the option, see `default()` */
        default?: any;
        /** string, use this description for the default value in help content, see `default()` */
        defaultDescription?: string;
        /**
         *  @deprecated since version 6.6.0
         *  Use 'demandOption' instead
         */
        demand?: boolean | string;
        /** boolean or string, demand the option be given, with optional error message, see `demandOption()` */
        demandOption?: boolean | string;
        /** string, the option description for help content, see `describe()` */
        desc?: string;
        /** string, the option description for help content, see `describe()` */
        describe?: string;
        /** string, the option description for help content, see `describe()` */
        description?: string;
        /** boolean, indicate that this key should not be reset when a command is invoked, see `global()` */
        global?: boolean;
        /** string, when displaying usage instructions place the option under an alternative group heading, see `group()` */
        group?: string;
        /** don't display option in help output. */
        hidden?: boolean;
        /**  string or object, require certain keys to be set, see `implies()` */
        implies?: string | ReadonlyArray<string> | { [key: string]: string | ReadonlyArray<string> };
        /** number, specify how many arguments should be consumed for the option, see `nargs()` */
        nargs?: number;
        /** boolean, apply path.normalize() to the option, see `normalize()` */
        normalize?: boolean;
        /** boolean, interpret option as a number, `number()` */
        number?: boolean;
        /**
         *  @deprecated since version 6.6.0
         *  Use 'demandOption' instead
         */
        require?: boolean | string;
        /**
         *  @deprecated since version 6.6.0
         *  Use 'demandOption' instead
         */
        required?: boolean | string;
        /** boolean, require the option be specified with a value, see `requiresArg()` */
        requiresArg?: boolean;
        /** boolean, skips validation if the option is present, see `skipValidation()` */
        skipValidation?: boolean;
        /** boolean, interpret option as a string, see `string()` */
        string?: boolean;
        type?: "array" | "count" | PositionalOptionsType;
    }

    interface PositionalOptions {
        /** string or array of strings, see `alias()` */
        alias?: string | ReadonlyArray<string>;
        /** value or array of values, limit valid option arguments to a predefined set, see `choices()` */
        choices?: Choices;
        /** function, coerce or transform parsed command line values into another value, see `coerce()` */
        coerce?: (arg: any) => any;
        /** string or object, require certain keys not to be set, see `conflicts()` */
        conflicts?: string | ReadonlyArray<string> | { [key: string]: string | ReadonlyArray<string> };
        /** value, set a default value for the option, see `default()` */
        default?: any;
        /** string, the option description for help content, see `describe()` */
        desc?: string;
        /** string, the option description for help content, see `describe()` */
        describe?: string;
        /** string, the option description for help content, see `describe()` */
        description?: string;
        /** string or object, require certain keys to be set, see `implies()` */
        implies?: string | ReadonlyArray<string> | { [key: string]: string | ReadonlyArray<string> };
        /** boolean, apply path.normalize() to the option, see normalize() */
        normalize?: boolean;
        type?: PositionalOptionsType;
    }

    /** Remove keys K in T */
    type Omit<T, K> = { [key in Exclude<keyof T, K>]: T[key] };

    /** Remove undefined as a possible value for keys K in T */
    type Defined<T, K extends keyof T> = Omit<T, K> & { [key in K]: Exclude<T[key], undefined> };

    /** Convert T to T[] and T | undefined to T[] | undefined */
    type ToArray<T> = Array<Exclude<T, undefined>> | Extract<T, undefined>;

    /** Gives string[] if T is an array type, otherwise string. Preserves | undefined. */
    type ToString<T> = (Exclude<T, undefined> extends any[] ? string[] : string) | Extract<T, undefined>;

    /** Gives number[] if T is an array type, otherwise number. Preserves | undefined. */
    type ToNumber<T> = (Exclude<T, undefined> extends any[] ? number[] : number) | Extract<T, undefined>;

    type InferredOptionType<O extends Options | PositionalOptions> =
        O extends { default: infer D } ? D :
        O extends { type: "count" } ? number :
        O extends { count: true } ? number :
        O extends { required: string | true } ? RequiredOptionType<O> :
        O extends { require: string | true } ? RequiredOptionType<O> :
        O extends { demand: string | true } ? RequiredOptionType<O> :
        O extends { demandOption: string | true } ? RequiredOptionType<O> :
        RequiredOptionType<O> | undefined;

    type RequiredOptionType<O extends Options | PositionalOptions> =
        O extends { type: "array", string: true } ? string[] :
        O extends { type: "array", number: true } ? number[] :
        O extends { type: "array", normalize: true } ? string[] :
        O extends { type: "string", array: true } ? string[] :
        O extends { type: "number", array: true } ? number[] :
        O extends { string: true, array: true } ? string[] :
        O extends { number: true, array: true } ? number[] :
        O extends { normalize: true, array: true } ? string[] :
        O extends { type: "array" } ? Array<string | number> :
        O extends { type: "boolean" } ? boolean :
        O extends { type: "number" } ? number :
        O extends { type: "string" } ? string :
        O extends { array: true } ? Array<string | number> :
        O extends { boolean: true } ? boolean :
        O extends { number: true } ? number :
        O extends { string: true } ? string :
        O extends { normalize: true } ? string :
        O extends { choices: ReadonlyArray<infer C> } ? C :
        O extends { coerce: (arg: any) => infer T } ? T :
        unknown;

    type InferredOptionTypes<O extends { [key: string]: Options }> = { [key in keyof O]: InferredOptionType<O[key]> };

    interface CommandModule<T = {}, U = {}> {
        /** array of strings (or a single string) representing aliases of `exports.command`, positional args defined in an alias are ignored */
        aliases?: ReadonlyArray<string> | string;
        /** object declaring the options the command accepts, or a function accepting and returning a yargs instance */
        builder?: CommandBuilder<T, U>;
        /** string (or array of strings) that executes this command when given on the command line, first string may contain positional args */
        command?: ReadonlyArray<string> | string;
        /** string used as the description for the command in help text, use `false` for a hidden command */
        describe?: string | false;
        /** a function which will be passed the parsed argv. */
        handler: (args: Arguments<U>) => void;
    }

    type ParseCallback<T = {}> = (err: Error | undefined, argv: Arguments<T>, output: string) => void;
    type CommandBuilder<T = {}, U = {}> = { [key: string]: Options } | ((args: Argv<T>) => Argv<U>);
    type SyncCompletionFunction = (current: string, argv: any) => string[];
    type AsyncCompletionFunction = (current: string, argv: any, done: (completion: ReadonlyArray<string>) => void) => void;
    type PromiseCompletionFunction = (current: string, argv: any) => Promise<string[]>;
    type MiddlewareFunction<T = {}> = (args: Arguments<T>) => void;
    type Choices = ReadonlyArray<string | number | true | undefined>;
    type PositionalOptionsType = "boolean" | "number" | "string";
}

declare var yargs: yargs.Argv;
export = yargs;
