209 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			209 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| const { InvalidArgumentError } = require('./error.js');
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| 
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| // @ts-check
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| 
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| class Option {
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|   /**
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|    * Initialize a new `Option` with the given `flags` and `description`.
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|    *
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|    * @param {string} flags
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|    * @param {string} [description]
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|    */
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| 
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|   constructor(flags, description) {
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|     this.flags = flags;
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|     this.description = description || '';
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| 
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|     this.required = flags.includes('<'); // A value must be supplied when the option is specified.
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|     this.optional = flags.includes('['); // A value is optional when the option is specified.
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|     // variadic test ignores <value,...> et al which might be used to describe custom splitting of single argument
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|     this.variadic = /\w\.\.\.[>\]]$/.test(flags); // The option can take multiple values.
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|     this.mandatory = false; // The option must have a value after parsing, which usually means it must be specified on command line.
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|     const optionFlags = splitOptionFlags(flags);
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|     this.short = optionFlags.shortFlag;
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|     this.long = optionFlags.longFlag;
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|     this.negate = false;
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|     if (this.long) {
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|       this.negate = this.long.startsWith('--no-');
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|     }
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|     this.defaultValue = undefined;
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|     this.defaultValueDescription = undefined;
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|     this.envVar = undefined;
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|     this.parseArg = undefined;
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|     this.hidden = false;
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|     this.argChoices = undefined;
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|   }
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| 
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|   /**
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|    * Set the default value, and optionally supply the description to be displayed in the help.
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|    *
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|    * @param {any} value
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|    * @param {string} [description]
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|    * @return {Option}
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|    */
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| 
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|   default(value, description) {
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|     this.defaultValue = value;
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|     this.defaultValueDescription = description;
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|     return this;
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|   };
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| 
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|   /**
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|    * Set environment variable to check for option value.
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|    * Priority order of option values is default < env < cli
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|    *
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|    * @param {string} name
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|    * @return {Option}
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|    */
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| 
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|   env(name) {
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|     this.envVar = name;
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|     return this;
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|   };
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| 
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|   /**
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|    * Set the custom handler for processing CLI option arguments into option values.
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|    *
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|    * @param {Function} [fn]
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|    * @return {Option}
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|    */
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| 
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|   argParser(fn) {
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|     this.parseArg = fn;
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|     return this;
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|   };
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| 
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|   /**
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|    * Whether the option is mandatory and must have a value after parsing.
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|    *
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|    * @param {boolean} [mandatory=true]
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|    * @return {Option}
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|    */
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| 
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|   makeOptionMandatory(mandatory = true) {
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|     this.mandatory = !!mandatory;
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|     return this;
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|   };
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| 
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|   /**
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|    * Hide option in help.
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|    *
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|    * @param {boolean} [hide=true]
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|    * @return {Option}
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|    */
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| 
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|   hideHelp(hide = true) {
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|     this.hidden = !!hide;
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|     return this;
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|   };
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| 
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|   /**
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|    * @api private
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|    */
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| 
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|   _concatValue(value, previous) {
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|     if (previous === this.defaultValue || !Array.isArray(previous)) {
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|       return [value];
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|     }
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| 
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|     return previous.concat(value);
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|   }
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| 
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|   /**
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|    * Only allow option value to be one of choices.
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|    *
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|    * @param {string[]} values
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|    * @return {Option}
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|    */
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| 
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|   choices(values) {
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|     this.argChoices = values;
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|     this.parseArg = (arg, previous) => {
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|       if (!values.includes(arg)) {
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|         throw new InvalidArgumentError(`Allowed choices are ${values.join(', ')}.`);
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|       }
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|       if (this.variadic) {
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|         return this._concatValue(arg, previous);
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|       }
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|       return arg;
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|     };
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|     return this;
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|   };
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| 
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|   /**
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|    * Return option name.
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|    *
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|    * @return {string}
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|    */
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| 
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|   name() {
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|     if (this.long) {
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|       return this.long.replace(/^--/, '');
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|     }
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|     return this.short.replace(/^-/, '');
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|   };
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| 
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|   /**
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|    * Return option name, in a camelcase format that can be used
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|    * as a object attribute key.
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|    *
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|    * @return {string}
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|    * @api private
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|    */
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| 
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|   attributeName() {
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|     return camelcase(this.name().replace(/^no-/, ''));
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|   };
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| 
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|   /**
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|    * Check if `arg` matches the short or long flag.
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|    *
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|    * @param {string} arg
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|    * @return {boolean}
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|    * @api private
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|    */
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| 
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|   is(arg) {
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|     return this.short === arg || this.long === arg;
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|   };
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| }
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| 
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| /**
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|  * Convert string from kebab-case to camelCase.
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|  *
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|  * @param {string} str
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|  * @return {string}
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|  * @api private
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|  */
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| 
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| function camelcase(str) {
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|   return str.split('-').reduce((str, word) => {
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|     return str + word[0].toUpperCase() + word.slice(1);
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|   });
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| }
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| 
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| /**
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|  * Split the short and long flag out of something like '-m,--mixed <value>'
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|  *
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|  * @api private
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|  */
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| 
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| function splitOptionFlags(flags) {
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|   let shortFlag;
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|   let longFlag;
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|   // Use original very loose parsing to maintain backwards compatibility for now,
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|   // which allowed for example unintended `-sw, --short-word` [sic].
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|   const flagParts = flags.split(/[ |,]+/);
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|   if (flagParts.length > 1 && !/^[[<]/.test(flagParts[1])) shortFlag = flagParts.shift();
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|   longFlag = flagParts.shift();
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|   // Add support for lone short flag without significantly changing parsing!
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|   if (!shortFlag && /^-[^-]$/.test(longFlag)) {
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|     shortFlag = longFlag;
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|     longFlag = undefined;
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|   }
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|   return { shortFlag, longFlag };
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| }
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| 
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| exports.Option = Option;
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| exports.splitOptionFlags = splitOptionFlags;
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