handy

index.js

/**
 * A handy module pattern
 */
const Module = (function () {

    /*
     ** Private variables
     */
    let private = {
        i: 0
    }

    /**
     * An instance based method which will set an 
     * immutable key and/or define data on itself
     * 
     *  - item = Module.item('key', {foo:'bar'})     // undefined
     *  - item = new Module.item('key', {foo:'bar'}) // {foo: 'bar'}
     * 
     * Handy for things like, 
     * let row = new database.row('table', {
     *  foo: 'bar'
     * })
     */
    this.item = function (key, data) {
        let item = this
        if (data !== undefined) item = Object.assign(item, data)

        // define an immutable key on the instance
        Object.defineProperty(item, 'key', {
            value: key,
            writable: false,
            enumerable: false
        })
    }

    /**
     * A prototype method for the item instance 
     * 
     * let row = new database.row('table', {
     *  foo: 'bar'
     * })
     * row.store() // noice
     */
    this.item.prototype.store = function () {
        let row = this //?

        this.key //?

        return row
    }

    /**
     * Something to increase which is from a private var
     */
    this.i = private.i

    /**
     * Increment the private var
     */
    this.ip1 = function () {
        ++private.i
        return private.i
    }

    return this
})() //?.

//
let item = new Module.item('someItemKey', {
    someProp: 'A value'
}) //?.

item.key //?

item.store() //?

/*
** var scopes
*/
// local scoped
++Module.i //?
++Module.i //?
++Module.i //?
++Module.i //?
Module.i = 10 //?

// instance scope
Module.ip1() //?
Module.ip1() //?
Module.ip1() //?
Module.ip1() //?

// is 10
Module.i //?

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