Cypress automatically includes a Blob library and exposes it as Cypress.Blob.

Use Cypress.Blob to convert base64 strings to Blob objects. Useful for testing uploads.

Syntax

Cypress.Blob.method()

Usage

Correct Usage

Cypress.Blob.method()

Incorrect Usage

cy.Blob.method() // Errors, cannot be chained off 'cy'

Examples

Image Fixture

Using an image fixture

// programmatically upload the logo
cy.fixture('images/logo.png').as('logo')
cy.get('input[type=file]').then(function($input) {

  // convert the logo base64 string to a blob
  return Cypress.Blob.base64StringToBlob(this.logo, 'image/png')
    .then((blob) => {

      // pass the blob to the fileupload jQuery plugin
      // used in your application's code
      // which initiates a programmatic upload
      $input.fileupload('add', { files: blob })
    })
})

Getting dataUrl string

Create an img element and set its src to the dataUrl

return Cypress.Blob.imgSrcToDataURL('/assets/img/logo.png').then((dataUrl) => {
  const img = Cypress.$('<img />', { src: dataUrl })

  cy.get('.utility-blob').then(($div) => {
    // append the image
    $div.append(img)
  })
  cy.get('.utility-blob img').click().should('have.attr', 'src', dataUrl)
})