@js-data-tools/js-helpers/dist/esm/predicates.js

A set of JavaScript / TypeScript helper functions for parsing, converting, transforming and formatting data.

export function alwaysTrue(input) {
    return true;
}
export function isUndefined(input) {
    return input === undefined;
}
export function isNullOrUndefined(input) {
    return input === undefined || input === null;
}
export function notNullOrUndefined(input) {
    return input !== undefined && input !== null;
}
export function isEmptyArray(input) {
    return !input || (Array.isArray(input) && !input.length);
}
export function isNonEmptyArray(input) {
    return Array.isArray(input) && input.length > 0;
}
export function isEmptySet(input) {
    return !input || !input.size;
}
export function isNonEmptySet(input) {
    return !!input && input.size > 0;
}
export function isEmptyMap(input) {
    return !input || !input.size;
}
export function isNonEmptyMap(input) {
    return !!input && input.size > 0;
}
export function isEmptyObject(input) {
    return !input || !Object.keys(input).length;
}
export function isNonEmptyObject(input) {
    return !!input && Object.keys(input).length > 0;
}
export function isEmptyValue(value) {
    if (value === null || value === undefined) {
        return true;
    }
    switch (typeof value) {
        case "string":
            return !value;
        case "object":
            if (Array.isArray(value)) {
                return !value.length;
            }
            return !Object.keys(value).length;
    }
    return false;
}
export function isDefaultValue(value) {
    if (value === null || value === undefined) {
        return true;
    }
    switch (typeof value) {
        case "object":
            if (Array.isArray(value)) {
                return !value.length;
            }
            return !Object.keys(value).length;
        default:
            return !value;
    }
}
export function and(...predicates) {
    const conditions = predicates?.filter(notNullOrUndefined);
    if (!conditions || conditions.length === 0) {
        return alwaysTrue;
    }
    if (conditions.length === 1) {
        return conditions[0];
    }
    return (input) => conditions.every((test) => test(input));
}
export function or(...predicates) {
    const conditions = predicates?.filter(notNullOrUndefined);
    if (!conditions || conditions.length === 0) {
        return alwaysTrue;
    }
    if (conditions.length === 1) {
        return conditions[0];
    }
    return (input) => conditions.some((test) => test(input));
}
export function not(predicate) {
    return (input) => !predicate(input);
}