nodeargs

Yet another process argument parser for node.

Installation

npm install PgBiel/nodeargs

Usage

The export will always have a property named args and rawArgs which are, respectively, the raw arguments but without the node part and the raw arguments with the node part. And with node part I mean this part:

node yourScript.js

Parsing arguments

To make it load arguments, use the setArgs function. Let's create an example file:

const nodeargs = require("nodeargs");

(Note: Even though I'm using ES6 syntax here, this module also works in ES5 and some older versions)

The setArgs takes an unlimited amount of objects that will "define" the arguments. Here are the possibilities:

  {
    name: "fullName", // full name of the argument, required (All others are optional). This sets the
    // -- call of the argument. E.g., if this is "hey", then you can use this with "--hey"
    description: "Does stuff", // description of the argument, used in help message (coming soon™)
    type: "string", // the type that the argument will parse to. Can be either string, number, boolean,
    // array, or path. Array and path are separated by a string set with options, explained a little later.
    optional: true, // if optional or not to have this argument (throws error even outside strict!), gonna
    // implement soon. Default value is true
    shortcut: "shortName", // short name of the argument (not required). This sets the - call of the
    // argument. E.g., if this is "h", then you can use this with "-h"
    example: "--fullName=JohnSmith", // an example of usage of the argument to be used in help message (soon™)
    multiple: false, // whether or not to allow multiple usages of this argument (if enabled, the last one is used)
    allowEmpty: false // whether or not to allow this argument to get an empty value, if this is enabled and it gets
    // one, then this argument will receive a default value depending on the type
  }

so we can use...

const nodeargs = require("nodeargs");
nodeargs.setArgs({ name: "name", type: "string", shortcut: "n" });

Next up, we have our options. To set one, use setOptions with a key value pair (setOptions(key, value). Any amount of those are accepted, but if you miss the value then it's an error!). Here are the valid options:

• strict -> Whether or not should the parser be strict (Default: false). When it is strict, it throws errors on invalid argument, repeated argument (if its multiple option is set to false), invalid type for argument and empty argument (if its allowEmpty option is set to false).

• caseSensitive -> Whether or not should the argument names be case sensitive. (Default: false)

• notFoundStr -> Error message given on argument not found and strict mode on. Tip: {arg} gets replaced with the argument call.

• invalidType -> Error message given on invalid argument type and strict mode on. Tip: {arg} gets replaced with the argument name and {type} with the correct type.

• repeatedArg -> Error message given on repeated argument, strict mode on and its multiple option disabled. Tip: {arg} gets replaced with the argument name.

• emptyArgErr -> Error message given on empty argument value, strict mode on and its allowEmpty option disabled. Tip: {arg} gets replaced with the argument name.

• pathSymbol -> String used to join the split path type into a string (Default: "/"). Please note that this only affects the output; the value given will always be split by / and \ (the \ one is for Windows compatibility).

• arraySymbol -> String used to split an array type (Default: ","). This affects the input value.

• parseCache -> Limit of the parsing cache (Default: 1).

Let's add an option to our example script:

const nodeargs = require("nodeargs");
nodeargs.setArgs({ name: "name", type: "string", shortcut: "n" });
nodeargs.setOption("caseSensitive", true)

Done, now arguments are case sensitive.

Use parseArgs() to activate the argument parsing. Doing so will push to the latestParsed property of the module, or remove the first element of the array and push in case the cache limit defined at options is exceeded. It also returns the parsed arguments.

const nodeargs = require("nodeargs");
nodeargs.setArgs({ name: "name", type: "string", shortcut: "n" });
nodeargs.setOption("caseSensitive", true)
const parsed = nodeargs.parseArgs();

And now we can do stuff with our "parsed" variable! Yay!

How 2 Contribute

1. Edit the CoffeeScript part.
2. Compile it using Cake and the Cakefile.
3. Done. PR it.