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    onetime
    TypeScript icon, indicating that this package has built-in type declarations

    6.0.0 • Public • Published

    onetime

    Ensure a function is only called once

    When called multiple times it will return the return value from the first call.

    Unlike the module once, this one isn't naughty and extending Function.prototype.

    Install

    $ npm install onetime
    

    Usage

    import onetime from 'onetime';
    
    let index = 0;
    
    const foo = onetime(() => ++index);
    
    foo(); //=> 1
    foo(); //=> 1
    foo(); //=> 1
    
    onetime.callCount(foo); //=> 3
    import onetime from 'onetime';
    
    const foo = onetime(() => {}, {throw: true});
    
    foo();
    
    foo();
    //=> Error: Function `foo` can only be called once

    API

    onetime(fn, options?)

    Returns a function that only calls fn once.

    fn

    Type: Function

    Function that should only be called once.

    options

    Type: object

    throw

    Type: boolean
    Default: false

    Throw an error when called more than once.

    onetime.callCount(fn)

    Returns a number representing how many times fn has been called.

    Note: It throws an error if you pass in a function that is not wrapped by onetime.

    import onetime from 'onetime';
    
    const foo = onetime(() => {});
    
    foo();
    foo();
    foo();
    
    console.log(onetime.callCount(foo));
    //=> 3

    fn

    Type: Function

    Function to get call count from.

    onetime for enterprise

    Available as part of the Tidelift Subscription.

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    Install

    npm i onetime

    DownloadsWeekly Downloads

    25,488,890

    Version

    6.0.0

    License

    MIT

    Unpacked Size

    5.88 kB

    Total Files

    5

    Last publish

    Collaborators

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