Run Exported Functions Directly From The Command Line

What's the quickest way to trial a function you're exporting?

Doing this in your shell?

$node
>require('./your_file').addOneTo(3)
4

No. That's annoying. And you have to repeat it all every time you change your_file.js.

Rather insert the following __at the end__ of your_file.js to expose its exports to the command line:

require('make-runnable');

That's it. Now you can do:

$node your_file.js addOneTo 3
4

Syntax

Call your function with several args:

node [your_file] [function_name] firstArg secondArg

Or call it with a single object:

node [your_file] [function_name] --key1 value1 --key2 value2

Full Example

Let's say you have the following file:

your_file.js

module.exports = {
addTogether: function(x,y){
return x + y
}, doSomethingWithObject: function(object){
object.newKey = "easy AF";
return object;
}, simpleValue: 'also works'
};
require('make-runnable');

You can now do the following:

$sh

node your_file.js addTogether 1 2
> 3
node your_file.js doSomethingWithObject --x 1 --y hello
> {x: 1, y: 'hello', newKey: 'easy AF'}
node your_file.js simpleValue
> also works

How does it work?

1. require.main === module is used to check if the module is being run directly, or imported.
2. If it's being run directly, then yargs is used to parse process.argv so that the target function may be called with the desired arguments.

What if you want to:

$3

Just leave off the function name, like so:

say_hello.js

module.exports = function(){console.log('hello');};

$sh

node say_hello.js
> hello

$3

The output is automatically printed.

$3

That happens automatically.

$3

You can pass in a custom option to make-runnable to remove that, like this:
``
require('make-runnable/custom')({
printOutputFrame: false
})
`

$3


You can pass in a custom option to make-runnable to hide the output message and frame generated by make-runnable:
`
require('make-runnable/custom')({
printOutput: false
})
`

$3

You can pass in a custom option to make-runnable to hide error messages and frames generated by make-runnable:
`
require('make-runnable/custom')({
printErrorOutput: false
})
``

$3

While you can pass a single object, or multiple primitives, multiple objects are not currently supported. PRs welcome!