skillshare-implement-feature

Implement a feature following TDD workflow. $ARGUMENTS is a spec file path (e.g., `specs/my-feature.md`) or a plain-text feature description.

**Scope**: This skill writes Go code and tests. It does NOT update website docs (use `update-docs` after) or CHANGELOG (use `changelog` after).

## Workflow

### Step 1: Understand Requirements

If $ARGUMENTS is a file path:
1. Read the spec file
2. Extract acceptance criteria and edge cases
3. Identify affected packages

If $ARGUMENTS is a description:
1. Search existing code for related functionality
2. Identify the right package to extend
3. Confirm scope with user before proceeding

### Step 2: Identify Affected Files

List all files that will be created or modified:

```bash
# Typical pattern for a new command
cmd/skillshare/<command>.go          # Command handler
cmd/skillshare/<command>_project.go  # Project-mode handler (if dual-mode)
internal/<package>/<feature>.go      # Core logic
tests/integration/<command>_test.go  # Integration test
```

Display the file list and continue. If scope is unclear, ask the user.

### Step 3: Write Failing Tests First (RED)

Write integration tests using `testutil.Sandbox`:

```go
func TestFeature_BasicCase(t *testing.T) {
    sb := testutil.NewSandbox(t)
    defer sb.Cleanup()

    // Setup
    sb.CreateSkill("test-skill", map[string]string{
        "SKILL.md": "---\nname: test-skill\n---\n# Content",
    })

    // Act
    result := sb.RunCLI("command", "args...")

    // Assert
    result.AssertSuccess()
    result.AssertOutputContains("expected output")
}
```

Verify tests fail:
```bash
make test-int
# or run specific test:
go test ./tests/integration -run TestFeature_BasicCase
```

### Step 4: Implement (GREEN)

Write minimal code to make tests pass:

1. Follow existing patterns in `cmd/skillshare/` and `internal/`
2. Use `internal/ui` for terminal output (colors, spinners, boxes)
3. Add oplog instrumentation for mutating commands:
   ```go
   start := time.Now()
   // ... do work ...
   e := oplog.NewEntry("command-name", statusFromErr(err), time.Since(start))
   oplog.Write(configPath, oplog.OpsFile, e)
   ```
4. Register command in `main.go` commands map if new command

Verify tests pass:
```bash
make test-int
```

### Step 5: Refactor and Verify

1. Clean up code while keeping tests green
2. Run full quality check:
   ```bash
   make check  # fmt-check + lint + test
   ```
3. Fix any formatting or lint issues

## Project Patterns Reference

These patterns appear throughout the codebase. Follow them when implementing new features.

### Handler Split Convention

Large commands are split by concern rather than kept in a single file. When a command handler grows beyond ~300 lines, split it:

| Suffix | Purpose | Example |
|--------|---------|---------|
| `<cmd>.go` | Flag parsing + mode routing (dispatch) | `install.go` |
| `_handlers.go` | Core handler logic | `install_handlers.go` |
| `_render.go` / `_audit_render.go` | Output rendering | `audit_render.go` |
| `_prompt.go` / `_prompt_tui.go` | Decision/prompt logic | `install_prompt.go` |
| `_tui.go` | Full-screen TUI (bubbletea) | `list_tui.go` |
| `_batch.go` | Batch operation orchestration | `update_batch.go` |
| `_resolve.go` | Target/skill resolution | `update_resolve.go` |
| `_context.go` | Mode-specific context struct | `install_context.go` |
| `_format.go` | Output formatting helpers | `log_format.go` |

**Principle**: dispatch file does ONLY flag parsing + mode routing. Logic goes in sub-files.

### Dual-Mode Command Pattern

Most commands support both global (`-g`) and project (`-p`) mode:

```go
func handleMyCommand(args []string) error {
    mode, rest, err := parseModeArgs(args)
    if err != nil { return err }

    switch mode {
    case modeProject:
        return handleMyCommandProject(rest)
    default:
        return handleMyCommandGlobal(rest)
    }
}
```

Create `<cmd>_project.go` for project-mode handler. Use `parseModeArgs()` from `mode.go`.

### TUI Components (bubbletea)

All interactive prompts use **bubbletea** (not survey). Key components:

- `checklist_tui.go` — shared checklist/radio picker
- `list_tui.go` — filterable list with detail panel
- `search_tui.go` — multi-select checkbox list

Color palette: cyan `Color("6")`, gray `Color("8")`, yellow `#D4D93C`.

Dispatch order: JSON output → TUI (if TTY + items + !`--no-tui`) → empty check → plain text.

### Web API Endpoint

If the feature needs a Web UI endpoint, add `internal/server/handler_<name>.go`:

```go
func (s *Server) handle<Name>(w http.ResponseWriter, r *http.Request) {
    // ...
    writeJSON(w, result)       // 200 OK with JSON
    // writeError(w, 400, msg) // for errors
}
```

Register in `server.go` route setup. Branch on `s.IsProjectMode()` for mode-specific behavior.

### Oplog Instrumentation

All mutating commands log to `operations.log` (JSONL):

```go
start := time.Now()
// ... do work ...
e := oplog.NewEntry("command-name", statusFromErr(err), time.Since(start))
e.Args = map[string]any{"key": value}
oplog.Write(configPath, oplog.OpsFile, e)
```

Security scans write to `oplog.AuditFile` instead.

### Step 6: E2E Runbook (Major Features Only)

If the feature meets **any** of these criteria, generate an E2E runbook:
- New command or subcommand
- Changes to install/uninstall/sync flow
- Security-related (audit, hash verification, rollback)
- Multi-step user workflow (init → install → sync → verify)
- Edge cases that integration tests alone can't cover (Docker, network, file permissions)

Generate `ai_docs/tests/<slug>_runbook.md` following the existing convention:

```markdown
# CLI E2E Runbook: <Title>

<One-line summary of what this validates.>

**Origin**: <version> — <why this runbook exists>

## Scope

- <bullet list of behaviors being validated>

## Environment

Run inside devcontainer with `ssenv` isolation.

## Steps

### 1. Setup: <description>

\```bash
<commands>
\```

**Expected**: <what should happen>

### 2. <Action>: <description>
...