unit-test-loop

name	unit-test-loop
description	This skill should be used when the user asks to "improve test coverage", "add unit tests", "TDD", "test this module", "write tests for", "increase coverage", "/ut command", or discusses unit testing strategies. Covers the unit test loop workflow, React Testing Library best practices, query priorities, and coverage improvement strategies.
version	2.0.0

Unit Test Loop - Coverage Improvement

Current branch: !git branch --show-current 2>/dev/null || echo "not in git repo"

The unit test loop uses a 2-phase workflow with Dex task tracking for persistent, cross-session test coverage improvement.

The 2-Phase Approach

Phase	Name	Purpose
1	Coverage Analysis	Identify gaps, prioritize files
2	Dex Handoff	Create epic + tasks from analysis

After Phase 2, use /complete <task-id> for each test task.

Starting the Loop

/ut "Improve coverage for auth module"            # Basic
/ut "Add tests" --target 80%                      # With target

Phase 1: Coverage Analysis

1. Run coverage command to see current state
2. Identify files with low coverage
3. Prioritize 3-7 test tasks for user-facing behavior

Output: <phase_complete phase="1"/>

Phase 2: Dex Handoff

Create Dex epic with target, then tasks for each gap:

# Create epic
dex create "Unit Test Coverage" --description "Target: 80% coverage"

# For each gap
dex create "Test: login validation" --parent <epic-id> --description "
File: src/auth/login.ts
Current: 45%

Test should verify:
- [ ] Valid credentials succeed
- [ ] Invalid credentials show error
"

Output: <phase_complete phase="2"/> or <promise>UT SETUP COMPLETE</promise>

Working on Tasks

Use Dex + /complete workflow:

dex list --pending      # See what's ready
dex start <id>          # Start working
/complete <id>          # Run reviewers and complete

React Testing Library Patterns

"The more your tests resemble the way your software is used, the more confidence they can give you."

Query Priority (Use in Order)

Priority	Query	Use Case
1	getByRole	Default choice, use name option
2	getByLabelText	Form fields with labels
3	getByPlaceholderText	Only if no label available
4	getByText	Non-interactive elements
5	getByTestId	Last resort only

Query Types

Type	When to Use
getBy/getAllBy	Element exists (throws if not found)
queryBy/queryAllBy	Only for asserting absence
findBy/findAllBy	Async elements (returns Promise)

Best Practices

// Use screen
screen.getByRole('button', { name: /submit/i })

// Use userEvent.setup()
const user = userEvent.setup()
await user.click(button)

// Use jest-dom matchers
expect(button).toBeDisabled()  // Not: expect(button.disabled).toBe(true)

// Avoid act() - RTL handles it
await screen.findByText('Loaded')  // Not: act(() => ...)

Quality Standards

• ONE test per task - Focused, reviewable commits
• User-facing behavior only - Test what users depend on
• Quality over quantity - One great test beats ten shallow ones
• No coverage gaming - Use /* v8 ignore */ for untestable code

Command Reference

/ut "prompt"                  # Start analysis
/ut "prompt" --target 80%     # With target
/cancel-ut                    # Cancel loop
/complete <task-id>           # Complete task with reviewers

Related

• /complete - Run reviewers and mark Dex task complete
• dex list - View pending tasks
• dex-workflow skill - Full Dex usage patterns