isTextContext

spec.ts

describe('#isTestContext', () => {
        beforeEach(() => {
            delete process.env.JEST_WORKER_ID;
            delete (window as any).__karma__;
            delete (window as any).Cypress;
        });
        it('#isTestContext should be true for Jest', () => {
            expect(isTestContext()).toBe(false);
            process.env.JEST_WORKER_ID = '1';
            expect(isTestContext()).toBe(true);
        });
        it('#isTestContext should be true for Karma', () => {
            expect(isTestContext()).toBe(false);
            (window as any).__karma__ = {};
            expect(isTestContext()).toBe(true);
        });
        it('#isTestContext should be true for Cypress', () => {
            expect(isTestContext()).toBe(false);
            (window as any).Cypress = {};
            expect(isTestContext()).toBe(true);
        });
    });

test-utils.ts

/**
 * Returns true if code is executed in test (i.e. Karma/Jest) context.
 */
export function isTestContext(): boolean {
    const isKarma: boolean = !!(window as any).__karma__;
    const isJest: boolean = 'undefined' !== typeof process && !!process.env.JEST_WORKER_ID;
    const isCypress: boolean = !!(window as any).Cypress;
    return isKarma || isJest || isCypress;
}