How to drag and drop custom file using Cypress

Step 1: Simulating Drag-and-Drop Events

Cypress does not provide built-in commands for dragging files, but you can achieve this by simulating drag-and-drop events. Common drag-and-drop events include dragstart, dragover, and drop. When simulating these events, construct a drag-and-drop event object and include the file information within it.

Step 2: Constructing Event Objects and File Information

You need to construct a DataTransfer object containing the file information and pass it to the simulated drag-and-drop events.

javascript
// Construct DataTransfer object
const dataTransfer = new DataTransfer();
dataTransfer.items.add(new File(['file content'], 'filename.txt'));

Step 3: Triggering Drag-and-Drop Events

Use Cypress's .trigger() command to trigger drag-and-drop related events and pass the constructed event object as a parameter.

javascript
// Get the drag-and-drop target element
 cy.get('.drop-zone')
   // Trigger dragstart event
   .trigger('dragstart', { dataTransfer })
   // Trigger dragover event
   .trigger('dragover', { dataTransfer })
   // Trigger drop event
   .trigger('drop', { dataTransfer });

Example Code

Below is a complete example demonstrating how to implement a file drag-and-drop operation in a Cypress test:

javascript
describe('Custom File Drag and Drop', () => {
  it('should drag and drop a custom file', () => {
    cy.visit('http://localhost:3000'); // Replace with your test page URL

    // Construct DataTransfer object
    const dataTransfer = new DataTransfer();
dataTransfer.items.add(new File(['file content'], 'filename.txt'));

    // Get the drag-and-drop target element and simulate drag-and-drop events
    cy.get('.drop-zone')
      .trigger('dragstart', { dataTransfer })
      .trigger('dragover', { dataTransfer })
      .trigger('drop', { dataTransfer });

    // Verify the file was correctly dragged
    cy.get('.file-list').should('contain', 'filename.txt'); // Assuming the file name is displayed in the .file-list element after drag-and-drop
  });
});

Important Notes

• When constructing DataTransfer and File objects, ensure that the file content and name align with your test scenario.
• When simulating drag-and-drop events, ensure that the event types (e.g., dragstart, dragover, drop) and the triggering order match the actual user interaction.
• After the test, perform appropriate assertions to verify that the drag-and-drop operation results match expectations.

Through the above steps, you can simulate custom file drag-and-drop operations in Cypress and perform automated testing.