How open connection with indexedDB for Cypress tests?

When using Cypress for end-to-end testing, you can interact with and establish connections to IndexedDB in multiple ways. The following provides a step-by-step guide and example demonstrating how to open a connection to IndexedDB in Cypress:

Step 1: Create a Custom Command

In Cypress tests, add custom commands to the commands.js file to encapsulate IndexedDB interaction logic. This keeps the main test file organized and allows reusing the IndexedDB connection logic.

javascript
// cypress/support/commands.js

Cypress.Commands.add("openIndexedDB", (dbName, version) => {
  return new Cypress.Promise((resolve, reject) => {
    const request = indexedDB.open(dbName, version);

    request.onerror = (event) => {
      reject(event.target.errorCode);
    };

    request.onsuccess = (event) => {
      resolve(event.target.result);
    };

    request.onupgradeneeded = (event) => {
      const db = event.target.result;
      // Initialize the database, create object stores, etc.
    };
  });
});

Step 2: Use the Custom Command in Test Cases

In your test script, call cy.openIndexedDB() to establish the IndexedDB connection. Pass the database name and version number as needed.

javascript
// cypress/integration/sample_spec.js

describe('IndexedDB Test', () => {
  it('should open a connection to IndexedDB', () => {
    cy.openIndexedDB('myTestDB', 1).then((db) => {
      expect(db).to.be.a('IDBDatabase');
      // Perform additional operations or assertions
    });
  });
});

Example Explanation

In this example:

• We define a new Cypress command openIndexedDB in cypress/support/commands.js.
• This command handles opening an IndexedDB connection and provides callbacks for error handling and successful responses.
• In the test script sample_spec.js, we call this command and assert that the returned object is of type IDBDatabase upon successful connection.

This approach makes interacting with IndexedDB in tests more modular and manageable. When using Cypress for such operations, properly handling the asynchronous nature of IndexedDB is essential.