Testing a Salesforce App: Apex vs Selenium vs DevAssure O2 — A Side-by-Side Comparison
Short answer
Apex validates server logic fast but cannot see the UI. Selenium covers user flows but breaks on Shadow DOM, MFA, and every release. DevAssure O2 runs plain-English tests in a real browser — same UI coverage as Selenium without locator maintenance. Use Apex + O2, not Apex + brittle scripts.
Every Salesforce team tests. The question is how — and what slips through the cracks depending on which approach you use.
In this post, I'm going to take a real Salesforce application — Dreamhouse, Salesforce's official sample app — and test the same functionality three different ways:
- Apex unit tests (the traditional Salesforce-native approach)
- Selenium WebDriver (the industry-standard UI automation approach)
- DevAssure O2 Agent (autonomous browser-based testing)
For each approach, I'll show you the actual code, explain what it catches, what it misses, and the ongoing maintenance cost. By the end, you'll have a clear picture of where each approach fits — and where it falls short.
