When you test signup on Vercel preview deployments, each Pull Request URL becomes a unique origin. This breaks cookies and magic links, making automated signup testing a hassle. To address this, you can use FakeSignup to handle the email and OTP generation, which keeps the process localized to the browser tab and avoids cross-origin issues.
Handling Origin Changes for Signup Testing
Vercel's preview deployments are fantastic for iterating quickly, but they introduce a challenge for automated testing. Each new PR gets its own temporary URL. When your signup flow relies on cookies to maintain session state, or when magic links are sent, these links point to a specific origin. When that origin disappears or changes with the next deploy, your tests fail because the cookie is gone, or the magic link points to a dead URL. FakeSignup helps here because it generates the temporary email address and receives the OTP directly within the browser. This means the email verification happens in the same tab, and the OTP is readily available without needing to navigate to a separate email client or deal with cross-origin communication for the verification code itself.
Automating Signup with Temporary Emails and OTPs
The core problem with testing signups on Vercel preview deployments is the ephemeral nature of the URLs. You need a reliable way to receive verification emails and one-time passcodes without them being tied to a specific, potentially short-lived, domain. FakeSignup provides a temporary email address for each test. When the signup form submits, the verification email lands in FakeSignup's inbox, which is accessible via a browser extension panel. You can then retrieve the OTP directly from this panel and paste it into the signup form, completing the verification step within the context of the current Vercel preview URL. This avoids the need for a dedicated email server or complex mail parsing in your CI pipeline for these specific origin-bound tests.
Setting Up FakeSignup
To start using FakeSignup for your Vercel preview testing, you'll need to install the browser extension.
- Install the Extension: Go to the FakeSignup on the Chrome Web Store and click "Add to Chrome."
- Open the Extension: Once installed, click the FakeSignup icon in your browser's toolbar. This opens a side panel.
- Generate an Email: In the side panel, click the button to generate a new temporary email address. Copy this email address.
- Use in Signup Form: Paste the generated email address into the email field of the signup form on your Vercel preview deployment.
- Submit the Form: Complete and submit the signup form.
- Retrieve OTP: Go back to the FakeSignup side panel. The verification email should appear there shortly. Open the email to find the OTP.
- Enter OTP: Copy the OTP from the FakeSignup panel and paste it into the OTP field on your signup form.
This process ensures that the email address and the subsequent OTP are handled within the current browser session, mitigating issues caused by changing Vercel preview URLs.
Integrating into Test Suites
When building automated test suites, particularly for CI environments running on Vercel preview deployments, you'll want to integrate this manual-like process into your scripts. While the full automation of receiving and injecting OTPs directly into the form might require browser automation tools like Playwright or Cypress, FakeSignup simplifies the email generation and retrieval part. Your test script can instruct the user (or an automated agent) to open the FakeSignup panel, generate an email, and then retrieve the code. For fully automated runs, you can use FakeSignup's premium features to programmatically retrieve OTPs, which is essential for reliable test signup on Vercel preview deployments. These saved accounts can persist in Chrome's local storage, meaning your test accounts remain available across browser sessions.
Considerations for Dynamic Origins
The primary benefit of using FakeSignup in this scenario is its independence from a fixed origin. Each temporary email generated is unique and associated with the browser extension's storage. When you are testing signup on Vercel preview deployments, each PR gets a new URL. Your test script can generate a FakeSignup email, use it, and then retrieve the OTP from the extension's panel. The email verification link, if one is used instead of an OTP, will also be directed to the temporary inbox managed by the extension. This avoids the common failure point where magic links become invalid because the deployment URL has changed. The test remains contained within the browser's current context, making it resilient to Vercel's dynamic deployment URLs.