argsert

an argument validator [originally] for yargs

API

import argsert from 'argsert';

let passed;

try {
  passed = argsert([configurationString], arguments);
} catch (err) {
  if (err instanceof TypeError) {
    // a type was missing or incorrectly given
  } else {
    // otherwise, there was something wrong with the configuration
    // or the number of args passed in.
  }
}

Promise API

import argsertPromise from 'argsert/promise';

argsertPromise([configurationString], arguments)
  .then(passed => passed)
  .catch(err => {
    // same error as above
  });

Available Types

• array
• boolean
• buffer
• error
• function
• null
• number
• object
• promise [that passes then/is-promise]
• string
• symbol
• undefined

* wildcard:

allows for any type.

Configuration via configurationString

space-separated entries with the following syntax:

[optional arguments]

'[string|number] [object]':

• the first argument can be a string OR a number, or undefined
• the second argument can be an object literal, or undefined.

<required arguments>

'<object> <*>':

• the first argument must be an object literal
• the second argument can be any type, but must be provided.

Live Example

The following leverages argsert best because it is the most performant and easiest to read by:

setting argsert's this to the configurationString

function nodeStyleCallback(err, result) {
  // ...
  argsert.apply('<error|undefined|null> [object|string]', arguments);
  // ...
}

You can also look at the example tests for other ways to invoke argsert. To learn more you can read about JS' function methods: apply, bind, and call.