How to test file inputs with Cypress?

Question

How can I write an e2e test of flow that requires interaction with the file Input DOM element?

If it's a text input I can interact with it (check value, set value) etc as its a DOM component. But If I have a File Input element, I am guessing that the interaction is limited till I can open the dialog to select a File. I can't move forward and select the file I want to upload as the dialog would be native and not some browser element.

So how would I test that a user can correctly upload a file from my site? I am using Cypress to write my e2e tests.

Answer 1

NB : latest version of cypress supports selectFile - see other answer

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