chonky/src/util/helpers.ts

A File Browser component for React

// Used in React hooks to indicate empty deps are intentional.
import { MaybePromise, Nullable, WritableProps } from 'tsdef';

import { FileAction, FileActionEffect } from '../types/action.types';
import { Logger } from './logger';

// Used in contexts that need to provide some default value for a function.
// eslint-disable-next-line no-unused-vars,@typescript-eslint/no-unused-vars
export const NOOP_FUNCTION = (...args: any[]) => {
    Logger.warn(
        `The "NOOP_FUNCTION" from the constants module was called. ` +
            `This can indicate a bug in one of the components. Supplied args:`,
        args
    );
};

export const isPromise = <T>(value: MaybePromise<T> | any): value is Promise<T> => {
    if (typeof value !== 'object' || !value) return false;
    const then = (value as Promise<T>).then;
    return then && typeof then === 'function';
};

export const defineFileAction = <Action extends FileAction>(
    action: Action,
    effect?: FileActionEffect<FileAction>
): WritableProps<Action> => {
    if (action.__payloadType !== undefined && (action.hotkeys || action.button)) {
        const errorMessage =
            `Invalid definition was provided for file action "${action.id}". Actions ` +
            `that specify hotkeys or buttons cannot define a payload type. If ` +
            `your application requires this functionality, define two actions ` +
            `and chain them using effects.`;
        Logger.error(errorMessage);
        throw new Error(errorMessage);
    }

    action.effect = effect;
    return action;
};

/**
 * Recursively check the current element and the parent elements, going bottom-up.
 * Returns the first element to match the predicate, otherwise returns null if such
 * element is not found.
 */
export const findElementAmongAncestors = (
    maybeElement: HTMLElement | any,
    predicate: (maybeElement: HTMLElement | any) => boolean
): Nullable<HTMLElement> => {
    if (!maybeElement) return maybeElement;

    if (predicate(maybeElement)) return maybeElement;

    if (maybeElement.parentElement) {
        return findElementAmongAncestors(maybeElement.parentElement, predicate);
    }

    return null;
};

export const elementIsInsideButton = (buttonCandidate: HTMLElement | any): boolean => {
    return !!findElementAmongAncestors(
        buttonCandidate,
        (element: any) => element.tagName && element.tagName.toLowerCase() === 'button'
    );
};

export const getValueOrFallback = <T extends any>(
    value: T | undefined,
    fallback: T,
    desiredType?: 'boolean' | 'string' | 'number'
): NonNullable<T> => {
    if (desiredType) {
        return (typeof value === desiredType ? value : fallback) as NonNullable<T>;
    }
    return (value !== undefined ? value : fallback) as NonNullable<T>;
};