Debugging

When I write code it always runs first time and never has any bugs. But I'm also a pathological liar. Here are some function to make debugging your code a little easier.

Debugger()

The Debugger() function returns a debugging function. The first argument is a flag which determines if debugging is enabled. If this is true then the function will act as a wrapper around console.log. If it is false then it is an alias for the doNothing() function which, as the name suggests, does nothing.

import { Debugger } from '@abw/badger'

const debugOn  = Debugger(true);
const debugOff = Debugger(false);

debugOn('This message will be displayed: %s', 'Hello World!');
debugOff('This message will be NOT be displayed: %s', 'Hello World!');

The second argument is an optional prefix for debugging messages.

const debugPrefix = Debugger(true, 'DEBUG > ');
debugPrefix('This message will have a prefix');

The message will be displayed as:

DEBUG > This message will have a prefix

The third option is a color. This can be any of the color options supported by the color() function.

const debugColor = Debugger(true, 'DEBUG > ', 'bright cyan');
debugColor('This message will have a bright cyan prefix');

addDebug()

The addDebug() function takes an object reference as the first argument, followed by the same three options as for the Debugger() function. It adds the debugging function as the debug method in the object.

It can be used in the constructor method for an object like this:

import { addDebug } from '@abw/badger'

class MyClass {
  constructor(options={}) {
    addDebug(this, options.debug, options.debugPrefix, options.debugColor);
  }
  someMethod() {
    this.debug('Hello World!')
  }
}

Now you can enable debugging message in your class by passing a debug flag, and optionally, a debugPrefix or debugColor parameter, to the constructor.

const myObj = new MyClass({
  debug: true,
  debugPrefix: 'MyClass > '
});
myObj.someMethod();

With this configuration a debugging message will be printed:

MyClass > Hello World!

appStatus()

The appStatus() function is a simple wrapper around a function to either print a success message, or catch any errors thrown and display the error message.

import { prompt, appStatus } from '@abw/badger';

const app = appStatus(
  async () => {
    const n = await prompt('Enter an even number');
    if (n % 2) {
      throw `${n} is not an even number`
    }
    return `You entered ${n}`;
  }
)

app();

If the function is successful it should return a message which will be displayed to the user (in bright green, although you can't see that here).

✔ Enter an even number … 2
✓ You entered 2

If an error is thrown then the error message will be displayed in bright red.

✔ Enter an even number … 3
✗ 3 is not an even number