ts-cast/esm/engine/to-be.js

Runtime typechecking

import { withName } from '../helpers/names';
import { throwTypeError } from './throw-type-error';
const spy = (fn) => {
    let isCalled = false;
    const result = (...args) => {
        isCalled = true;
        return fn(...args);
    };
    Object.defineProperty(result, 'isCalled', {
        get: () => isCalled,
    });
    return result;
};
export const toBe = (casterFn, predicate, typeName = `${casterFn.name}<${predicate.name}>`) => withName((value, context, reportError = throwTypeError) => {
    const spyReportError = spy(reportError);
    const typedValue = casterFn(value, context, spyReportError);
    if (spyReportError.isCalled)
        return typedValue;
    if (!predicate(typedValue)) {
        reportError(`${typeName} expected${context ? ` in ${context}` : ''} but "${value}" received.`, context);
        return undefined;
    }
    return typedValue;
}, typeName);