how do you make an object callable and attach functions to it at the same time

user_12219726 0
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I'm using winston as a logger and in it you have a format namespace and function at the same time, so i can both call format() and access other functions via the namespace format.someFunction() as illustrated in the code below. Now i'm wondering how i can create an object like this myself?

const isRequest = format((info, _opts) => {
    if (info.isRequest) {
        return info
    }
    return false
})

export const logger = createLogger({
    level: 'info',
    format: format.combine(
        format.timestamp({
            format: 'YYYY-MM-DD HH:mm:ss'
        }),
        format.printf((info) => {
            return `${info.timestamp} ${info.level}: ${info.message}`
        })
    ),
    transports: [
        new transports.File({
            filename: errorLog,
            level: 'error'
        }),
        new transports.File({
            filename: requestLog,
            format: format.combine(isRequest())
        }),
        new transports.File({
            filename: combinedLog
        })
    ],
    exceptionHandlers: [
        new transports.File({
            filename: exceptionsLog
        })
    ]
})
javascript
1 Answers

It's JavaScript function expression. If you export it, it works pretty much the same. Hope this is what you mean.

More about function expression

let sayHello = function() {
  console.log("Hello")
}
sayHello.sayWorld = function() {
  console.log("World")
}

sayHello();
sayHello.sayWorld();

user_124535620
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