How to test File-Upload functionality?

Question

I am currently in a deep dive into Cypress and writing e2e tests for an application. I seem to have hit a road block when it comes to testing file upload functionality. Due to my beginner status as a QA engineer and the lack of Internet traffic on this specific issue I have reached and impasse. I came across Cypres.Blob in the Docs. Unfortunately there is not a lot of documented and I haven't been able to apply the examples to what I need to learn.

describe ('File Upload Test', () => {
    it('should upload a file', () => {
        let testfile = cy.fixture('../fixtures/cypresstest.txt')
        cy.get('input[type=file]').then(($input) => {
        return Cypress.Blob.base64StringToBlob(testfile, 'file/txt')
            .then((blob) => {
            $input.fileupload('add', { files: blob })
            })
        })
    })
});

Answer 1

I'm testing our file upload service like this:

Cypress.Commands.add('uploadFile', (fileNamePath, fileName, fileType = ' ', selector) => {
  cy.get(selector).then((subject) => {
    cy.fixture(fileNamePath, 'base64')
      .then(Cypress.Blob.base64StringToBlob)
      .then((blob) => {
        const el = subject[0]
        const testFile = new File([blob], fileName, {
          type: fileType,
        })
        const dataTransfer = new DataTransfer()
        dataTransfer.items.add(testFile)
        el.files = dataTransfer.files
      })
  })
})

Then in spec file. click upload button and wait for the file to load up:

cy.server().route('POST', api-upload-url).as('loadUp')
        cy.uploadFile('./pathToFile/' + fileName, fileName, fileType, fileInput);
        cy.get('.btn-upload.mat-raised-button.mat-primary').click()
        cy.wait('@loadUp').then((response) => {
            expect(response.method).to.eq('POST')
            expect(response.status).to.eq(200)
            expect(response.response.body.status).to.eq('OK')
        })

There's also a check for desired responses.

It's not super fancy and optimized. But it works in 3.1.5 and 3.2.0. It works using the electron 59 both headed and headless