Programmatically authenticate with identity server 4 (code flow + PKCE) via a custom Cypress command

cypress-login-command.ts

// Programmatically authenticate with identity server 4 (code flow + PKCE) via a custom Cypress command

Cypress.Commands.add('Login', (email,password) => {
    const identityServerUrl = '<your identity server url>';

    const getLoginPage = {
            method: 'GET',
            url: identityServerUrl + '/connect/authorize',
            qs: {
                response_type: 'code',
                client_id: '<your client id>',
                redirect_uri: '<your redirect url'>,
                scope: 'api1',
                // https://tonyxu-io.github.io/pkce-generator/
                code_challenge: '<your code challenge>',
                code_challenge_method: 'S256',
            }
    };


    cy.request(getLoginPage).then(response => {
            const htmlDocument = document.createElement('html');
            htmlDocument.innerHTML = response.body;
            const requestVerificationToken = htmlDocument.getElementsByTagName('form')[0].elements.__RequestVerificationToken.value;
            const loginUrl = response.allRequestResponses[1]["Request URL"];

            cy.request({
                method: 'POST',
                url: loginUrl,
                followRedirect: true,
                form: true,
                body: {
                    Email: email,
                    Password:password,
                    __RequestVerificationToken: requestVerificationToken
                }
            });
        });
});