npm install cypress-extender-arrays

yarn add cypress-extender-arrays

Once cypress-extender-arrays is installed use:

import 'cypress-extender-arrays';

Or use:

        require('cypress-extender-arrays');

Or add it to the plugin file.

        cy.get('li').map(e => e.text().trim()).then(texts => {
            cy.log('Texts are: ', texts);
        });

        cy.wrap([11,22,33]).map(e => e + 5).then(array => {
            cy.wrap(array[0]).should('eq', 16);
            cy.wrap(array[1]).should('eq', 27);
            cy.wrap(array[2]).should('eq', 38);
        });

    it('test array reduce with array', () => {
        cy.get('a').map(e => e.text()).reduce((acc, val) => {
            acc.push(val[0]);
            return acc;
        }, []).should('have.length.gt', 0);
    });

    it('test array reduce with string', () => {
        cy.get('a').map(e => e.text()).reduce((acc, val) => {
            acc += val[0] || '';
            return acc;
        }, '').should('have.length.gt', 0);
    });

    it('test array reduce with number', () => {
        cy.get('a').map(e => e.text()).reduce((acc, val) => acc += val.length, 0)
        .should('be.gt', 0);
    });

Use:

it('test that every from the prevSubjet is a string', () => {
    cy.get('a').map(e => e.text()).every(v => typeof v === 'string').should('be.true');
});

Use:

it('test join texts are given', () => {
    cy.get('a').map(e => e.text()).join("HOWAREYOU").should('include', 'HOWAREYOU');
});

Use:

    it('test array reverse', () => {
        cy.get('a').map(e => e.text()).reverse().then(values => {
            cy.get('a').reverse().map(e => e.text()).should('deep.eq', values);
        });
    });