How to use getInitialPluginsFilePath method in Cypress

Your question is a bit confusing, you say 5 test cases in single suite file but your example cypress run --spec 'cypress/integration/TestCase2.js implies individual spec files.

I'll give you an answer both ways.

Individual spec files

Please see the third example docs - cypress run --spec which runs two tests, comma separated.

cypress run --spec "cypress/integration/TestCase2.spec.js,cypress/integration/TestCase5.spec.js"

Single suite file

Please see How to add test case grouping in Cypress which uses a beforeEach() to check test names passed in by ENV variable.

Add this at the top of your single test suite

beforeEach(function() {

  const testFilter = Cypress.env('TEST_FILTER');
  if (!testFilter) return;                       // exit if no filter defined

  const testName = Cypress.mocha.getRunner().test.fullTitle();
  if (!testFilter.includes(testName)) {
    this.skip();
  }
})

Run with

set CYPRESS_TEST_FILTER=Test2;Test5 & cypress open

or

cypress open --env TEST_FILTER=Test2;Test5  

Note when using the --env flag, the test names must not be separated by a comma since Cypress uses that internally to delimit multiple ENV variables.

Try adding a click() before you type:

cy.get('#reasonRecommendationByAgent')
  .click()
  .type('Zdůvodnění doporučení zprostředkovatele', {force: true})
  .should('have.value', 'Zdůvodnění doporučení zprostředkovatele')

If you're sure that one or the other selector turns up eventually, combine them into a multiple selector.

Ref jQuery multiple selector.

The first one that turns up will be passed on

cy.get(`${successElementSelector}, ${failureElementSelector}`)
  .should($el => {
    expect($el.text()).to.include('Success!')  // whatever success data looks like
  })

Since it works when the intercept is moved up in the command order, it seems that cy.waitLoading() triggers the POST and not cy.get('[data-cy=alreadysent-button]').

The intercept must always be set up before the trigger (page visit or button click).

But the intercept varies between tests, so instead of before() I would try setting up a helper function that is called at the top of each test.

const loadAndIntercept = (apiResult) => {     
  const apiFixture = apiResult ? 'test/alreadySent-true.json' : 'test/alreadySent-false.json';
  cy.intercept('POST', '**/test/alreadySent', { fixture: apiFixture }).as('alreadySent');
  cy.waitLoading();
})

it('false test', function() {
  loadAndIntercept(false);
  cy.wait('@alreadySent');
  cy.get('[data-cy=alreadysent-button]');
});

it('true test', function() {
  loadAndIntercept(true);
  cy.wait('@alreadySent');
  cy.get('[data-cy=alreadysent-button]');
});

This should work since intercepts are cleared between tests. Ref docs - intercept

Note: all intercepts are automatically cleared before every test.

You mention this code for obtaining the value in version.

let version; 
getVersion((setVersion) => {   
  version = parseInt(setVersion.replace(/[v.]/g, ''));   
  console.log(version); //8203 
});
if (version < 8203) {  ??? is this where you test ???

If the above pattern is how your test looks, I'd say the getVersion() callback has not completed before the if() is evaluated.

Does this structure improve things?

let version; 
getVersion((setVersion) => {   
  version = parseInt(setVersion.replace(/[v.]/g, ''));   
  console.log(version); //8203 

  if (version < 8203) {  
    ...
  }
  else {
    context('Testing Feature', () => {
      it('Test 1', () => {
      ...
    });
  }
});

I'll just add that if you decide to do if condition by checking the .length property of cy.find command, you need to respect the asynchronous nature of cypress.

Example: Following condition evaluates as false despite appDrawerOpener button exists

    if (cy.find("button[data-cy=appDrawerOpener]").length > 0)    //evaluates as false

But this one evaluates as true because $body variable is already resolved as you're in .then() part of the promise:

    cy.get("body").then($body => {
        if ($body.find("button[data-cy=appDrawerOpener]").length > 0) {   
            //evaluates as true
        }
    });

Read more in Cypress documentation on conditional testing

You have to setup babel plugin plugin-transform-modules-commonjs with loose: true

[
    '@babel/plugin-transform-modules-commonjs',
    {
        loose: true,
    },
]

Example config of your cypress/plugins/index.js

const { startDevServer } = require('@cypress/webpack-dev-server');
const findReactScriptsWebpackConfig = require('@cypress/react/plugins/react-scripts/findReactScriptsWebpackConfig');

// taken from https://github.com/cypress-io/code-coverage/issues/461#issuecomment-859292331
function customDevServer(
    on,
    config,
    { webpackConfigPath } = {
        webpackConfigPath: 'react-scripts/config/webpack.config',
    }
) {
    on('dev-server:start', async (options) => {
        const webpackConfig = findReactScriptsWebpackConfig(config, {
            webpackConfigPath,
        });
        const rules = webpackConfig.module.rules.find((rule) => !!rule.oneOf).oneOf;
        const babelRule = rules.find((rule) => /babel-loader/.test(rule.loader));
        babelRule.options.plugins.push(require.resolve('babel-plugin-istanbul'), [
            '@babel/plugin-transform-modules-commonjs',
            {
                loose: true,
            },
        ]);
        return startDevServer({
            options,
            webpackConfig,
        });
    });

    config.env.reactDevtools = true;

    return config;
}

module.exports = (on, config) => {
    if (config.testingType === 'component') {
        customDevServer(on, config);
    }

    require('@cypress/code-coverage/task')(on, config);

    return config;
};

The issue link on github: https://github.com/cypress-io/cypress/issues/18662

it('Testing picture uploading', () => {
    cy.fixture('testPicture.png').then(fileContent => {
        cy.get('input[type="file"]').attachFile({
            fileContent: fileContent.toString(),
            fileName: 'testPicture.png',
            mimeType: 'image/png'
        });
    });
});

Use cypress file upload package: https://www.npmjs.com/package/cypress-file-upload

Note: testPicture.png must be in fixture folder of cypress

In your JSON you can add an extra field errorMessage and url.

[
  {
    "id": "standard User",
    "username": "standard_user",
    "password": "secret_sauce",
    "url": "https://www.saucedemo.com/inventory.html"
  },
  {
    "id": "locked out user",
    "username": "locked_out_user",
    "password": "secret_sauce",
    "errorMessage": "error 2"
  },
  {
    "id": "Problem user",
    "username": "problem_user",
    "password": "secret_sauce",
    "errorMessage": "error 3"
  },
  {
    "id": "perfromance glitch user",
    "username": "performance_glitch_user",
    "password": "secret_sauce",
    "errorMessage": "error 4"
  },
  {
    "id": "Invalid User",
    "username": "perform",
    "password": "secret12",
    "errorMessage": "error 5"
  }
]

You test should be like this:

it('Login with multiple users', () => {
  cy.readFile('users.json').then((users) => {
    users.forEach((user) => {
      cy.visit('/')
      cy.get('[data-test="username"]').type(user.username)
      cy.get('[data-test="password"]').type(user.password)
      cy.get('[data-test="login-button"]').click()
      if (user.username == 'standard_user') {
        cy.url().should('eq', user.url)
      } else {
        cy.get('[data-test="error"]').should('have.text', user.errorMessage)
      }
    })
  })
})