incremental-implementation

Incremental Implementation

Overview

Build in thin vertical slices — implement one piece, test it, verify it, then expand. Avoid implementing an entire feature in one pass. Each increment should leave the system in a working, testable state. This is the execution discipline that makes large features manageable.

When to Use

• Implementing any multi-file change
• Building a new feature from a task breakdown
• Refactoring existing code
• Any time you're tempted to write more than ~100 lines before testing

When NOT to use: Single-file, single-method changes where the scope is already minimal.

The Increment Cycle

┌──────────────────────────────────────┐
│                                      │
│   Implement ──→ Test ──→ Verify ──┐  │
│       ▲                           │  │
│       └───── Commit ◄─────────────┘  │
│              │                       │
│              ▼                       │
│          Next slice                  │
│                                      │
└──────────────────────────────────────┘

For each slice:

1. Implement the smallest complete piece of functionality
2. Test — run dotnet test (or write a test if none exists)
3. Verify — confirm the slice works as expected (tests pass, dotnet build -warnaserror is clean, manual check)
4. Commit -- save your progress with a descriptive message (see git-workflow-and-versioning for atomic commit guidance)
5. Move to the next slice — carry forward, don't restart

Slicing Strategies

Vertical Slices (Preferred)

Build one complete path through the stack:

Slice 1: Create a task (EF Core entity + migration + endpoint + basic view)
    → dotnet test passes, user can create a task via the UI

Slice 2: List tasks (query + endpoint + list view with bindings)
    → dotnet test passes, user can see their tasks

Slice 3: Edit a task (update command + endpoint + edit view)
    → dotnet test passes, user can modify tasks

Slice 4: Delete a task (delete command + endpoint + UI + confirmation)
    → dotnet test passes, full CRUD complete