Function _when

packages/mobx/src/api/when.ts:36–70

(predicate: () => boolean, effect: Lambda, opts: IWhenOptions)

}

function _when(predicate: () => boolean, effect: Lambda, opts: IWhenOptions): IReactionDisposer {
    let timeoutHandle: any
    if (typeof opts.timeout === "number") {
        const error = new Error("WHEN_TIMEOUT")
        timeoutHandle = setTimeout(() => {
            if (!disposer[$mobx].isDisposed) {
                disposer()
                if (opts.onError) {
                    opts.onError(error)
                } else {
                    throw error
                }
            }
        }, opts.timeout)
    }

    opts.name = __DEV__ ? opts.name || "When@" + getNextId() : "When"
    const effectAction = createAction(
        __DEV__ ? opts.name + "-effect" : "When-effect",
        effect as Function
    )
    // eslint-disable-next-line
    var disposer = autorun(r => {
        // predicate should not change state
        let cond = allowStateChanges(false, predicate)
        if (cond) {
            r.dispose()
            if (timeoutHandle) {
                clearTimeout(timeoutHandle)
            }
            effectAction()
        }
    }, opts)
    return disposer
}

function whenPromise(
    predicate: () => boolean,