11.3Pattern 2: Form Validation Testing

Test that forms reject invalid input correctly.

Example: Registration Form

# Test: empty form submission
playwright-cli goto https://app.example.com/register
playwright-cli snapshot
# → textbox "Email" [ref=e3], textbox "Password" [ref=e4], button "Create account" [ref=e5]
playwright-cli click e5                    # Submit empty form
playwright-cli snapshot
# → Agent verifies alerts in YAML: "Email is required", "Password is required"

# Test: invalid email
playwright-cli fill e3 "not-an-email"
playwright-cli click e5
playwright-cli snapshot
# → Agent verifies: "Please enter a valid email"

# Test: weak password
playwright-cli fill e3 "valid@test.com"
playwright-cli fill e4 "123"
playwright-cli click e5
playwright-cli snapshot
# → Agent verifies: "Password must be at least 8 characters"

# Test: valid submission
playwright-cli fill e3 "valid@test.com"
playwright-cli fill e4 "StrongP@ss123"
playwright-cli click e5
playwright-cli snapshot
# → Agent verifies: "Registration successful"

Agent's Added Value

The agent can generate test cases from the form structure:

• Read the snapshot to enumerate every field, its role, and its accessible name
• Generate boundary-value tests automatically
• Verify error messages match expected UX copy

(For a whole suite of such cases, this is exactly the planner → generator hand-off from the Test Agents chapter — the agent explores, writes a Markdown plan, and generated .spec.ts files do the repetitive execution.)