Universal Live Check

Universal Live Check Framework

Validate code changes in real-time with domain-adaptive, change-type-aware checks. Every check is incremental (only validates what changed), fast (<2s), and deterministic.

Gotchas

Generic checks miss domain bugs: A TypeScript-only check will miss Docker misconfigurations, missing environment variables, or mobile-specific API level issues. Always detect the domain first.

Blocking on slow checks kills flow: Live checks must be fast. Offload heavy checks (integration tests, full test suites) to async pipelines. Live checks verify immediately-correctable issues.

Change type changes strategy: A hotfix needs minimal validation to unblock deployment. A feat needs full API contract verification. Always determine change type before selecting checks.

Scope creep in libs: Library changes affect downstream consumers. A libs domain check must verify public API surface and semver compliance even for "minor" changes.

Quick Start

Input:  Files changed (or files to check), optional change type (feat|fix|hotfix|refactor|migrate|docs)
Output: Structured check report with pass/fail per check category

Workflow:
1. Classify domain(s) affected by the change
2. Determine change type via branch/commit/message analysis
3. Select checks per domain + change type
4. Run incremental checks (file-level first, then module-level)
5. Aggregate results into structured report
6. If failures: provide specific fix actions, not just symptoms

Activation

Load this skill when:

• User asks for live checks, lint validation, or code quality checks
• User mentions pre-commit, pre-push, or CI pre-flight
• Agent is about to complete a coding session and needs validation
• User asks to "verify", "check", "validate", or "test" code changes
• User asks to "run checks" or "check my work"
• Agent detects domain change (CLI→backend, frontend→mobile, etc.)

Do NOT load this skill for:

• Running full test suites (delegate to CI async pipeline)
• Questions about code without validating anything
• Already-passed checks that don't need re-running

Domain Classification

Detect affected domains by analyzing file paths, package manager files, and project structure.

Domain Detection Algorithm

1. Scan changed files for domain signals
2. Check for project config files:
   - package.json → frontend, libs, or CLI
   - pyproject.toml / requirements.txt → backend
   - Cargo.toml → embedded or libs
   - docker-compose.yml / Dockerfile → backend
   - android/ or ios/ directories → mobile
   - Makefile / *.c / *.h → embedded
3. Combine signals,权重 domain confidence
4. Return ordered list of domains with confidence scores

Domain Signal Map

New Addition Detection

For detecting NEW files/features (priority signals):

• bin/ directory with executable files → feat (new CLI tool)
• cli/ path prefix → feat (new CLI tool)
• New API routes in api/ → feat (new endpoint)
• New components in components/ → feat (new UI feature)
• First file in a new directory → feat (new module)

Multi-Domain Detection

Most changes affect multiple domains:

• api/ + ui/ changes → backend + frontend
• lib/ + cli/ changes → libs + CLI
• server/ + mobile/ changes → backend + mobile

Always run checks for ALL detected domains.

Change Type Detection

Detect the change type in priority order:

1. Explicit tag: User provides type tag (feat, fix, hotfix, refactor, migrate, docs)

2. Branch name scan: Check branch for conventional-commit prefixes:

   • feat/ → feat
   • fix/ → fix
   • hotfix/ → hotfix
   • refactor/ → refactor
   • chore/ → migrate
   • docs/ → docs

3. Commit message scan: Examine last 5 commit messages for prefixes (feat:, fix:, etc.)

4. Heuristic inference: Analyze diff size, files changed, and message language:

   • Large diff + many files → migrate or major feat
   • Few files + "fix" language → fix
   • "emergency" / "production down" → hotfix

5. File path patterns: Analyze file paths for change type signals:

   • cli/, bin/ → feat (new tool)
   • api/, routes/ + new file → feat (new endpoint)
   • components/ + new file → feat (new component)
   • fix/, bug/ in path → fix
   • hotfix/, patch/ → hotfix
   • migrate/, upgrade/ → migrate

6. Change size heuristics: Scale validation depth by change scope:

   • Single file, small change → focused check on affected lines
   • Multiple files → cross-file integration checks
   • New directory/first commit → full domain validation
   • 10+ files changed → check for scope creep and missing tests

7. Fallback: If no signal, use feat (most common, full validation)

Change Type Strategies

Universal Check Categories

These checks apply to ALL domains:

1. Build Integrity (Universal)

- File syntax is valid (parse error check)
- Dependencies are resolvable
- Required env vars are defined (not necessarily set)
- Config files are valid (JSON/YAML/TOML parse)

2. Naming & Conventions (Universal)

- File naming follows project conventions
- Exported symbols follow naming conventions
- No debug/console logs left in production code
- No TODO/FIXME comments without tracking issue

3. Security Surface (Universal)

- No hardcoded secrets (API keys, passwords, tokens)
- No SQL/command injection vectors
- Input validation present on boundaries
- Authentication/authorization checks on endpoints

4. Error Handling (Universal)

- All errors are caught or propagated
- Error messages don't leak internals
- Resource cleanup in finally/defer blocks
- No empty catch blocks swallowing errors

5. Testing Surface (Universal)

- New code has corresponding tests
- Tests are not just stubs (assertions present)
- Test file naming follows convention

6. Cross-Domain Contamination (Universal)

When multiple domains detected, check for cross-boundary issues:

- Imports between domains (libs → backend → frontend)
- Shared config affecting multiple outputs
- Peer dependencies misaligned with actual usage
- Type mismatches across domain boundaries

Domain-Specific Checks

Read the relevant reference file for domain-specific checks:

• CLI Checks — Command-line tool validation
• Backend Checks — API, database, service checks
• Frontend Checks — UI, accessibility, bundle
• Mobile Checks — iOS/Android specific validation
• Embedded Checks — Hardware, memory, cross-compile
• Libs Checks — Public API, semver, compatibility, cross-domain deps

Cross-domain detection is a key differentiator. When a libs check finds backend code importing a library function, that's a signal to also run backend checks on that file.

Check Execution Engine

Hierarchical Validation

Level 1: File-level (instant, ~10ms per file)
├── Syntax parse check
├── Naming convention check
├── No secrets scan (regex)
└── Import/resolution check

Level 2: Module-level (~100ms per module)
├── Type check (if applicable)
├── Unused export check
├── Dependency graph check
└── API contract check

Level 3: Project-level (~1s total)
├── Build/compilation check
├── Config consistency check
└── Integration surface check

Incremental Check Optimization

Only run checks affected by the changed files:

1. File changed → Run Level 1 for that file
2. API file changed → Run Level 2 for that module
3. Config file changed → Run Level 3 for project
4. Multiple files → Parallelize by file, aggregate results

Cross-Domain Contamination Detection

Critical for libs/domain packages: Changes in one domain can break another.

Run these checks when multiple domains are detected:

libs/consumer.ts imports backend/api.ts → Verify api.ts hasn't changed
frontend/page.tsx imports mobile/App.tsx → Flag cross-import
lib/utils.ts used in cli/wordcount.ts → Check lib doesn't break CLI

Signs of contamination:

• Import chain crosses domain boundaries
• Shared utilities used by multiple domains
• Config files that affect multiple outputs

When found: validate BOTH the changed file AND its consumers.

Check Result Format

{
  "domain": "backend",
  "change_type": "feat",
  "checks_run": 12,
  "passed": 10,
  "failed": 2,
  "results": [
    {
      "check": "api-contract",
      "level": "module",
      "status": "pass",
      "file": "api/users.rs",
      "message": "All endpoints have schema definitions"
    },
    {
      "check": "secrets-scan",
      "level": "file",
      "status": "fail",
      "file": "config/development.env",
      "line": 3,
      "message": "Potential API key hardcoded",
      "fix": "Move to environment variables or .env file"
    }
  ],
  "execution_time_ms": 847
}

Self-Healing Loop

For failed checks with auto-fix capability:

1. Attempt fix using known patterns
2. Re-run check to verify fix
3. If still failing: Mark as requires-attention, continue
4. After session: Report all unfixable issues with specific remediation steps

Never skip checks because auto-fix isn't available. Always report findings.

Reporting

Structured Report Format

# Live Check Report

**Domain:** backend | **Change Type:** feat
**Files:** 5 changed | **Checks:** 12 run | **Time:** 847ms

## Summary

| Status | Count |
|--------|-------|
| ✅ Passed | 10 |
| ❌ Failed | 2 |
| ⚠️ Warnings | 1 |

## Failed Checks

### 1. secrets-scan (HIGH)
**File:** `config/development.env:3`
```env
API_KEY=sk_live_abc123  # ← hardcoded secret

Fix: Move to environment variables, use .env.example template

2. api-contract (MEDIUM)

File: api/users.rs:45 Issue: Response schema missing email field for User type Fix: Add email: string to UserResponse schema

Warnings

• test_users.rs:12 — Test assertion too broad (consider using exact match)

Cross-Domain Findings

When contamination detected between domains:

**Contamination:** `libs/utils.ts` used by `api/users.ts`
**Issue:** `api/users.ts` imports `bcrypt` but `utils` doesn't export it
**Check:** Verify all imports are resolvable across domain boundaries

Next Steps

1. Fix 2 failed checks above
2. Run full test suite: cargo test
3. Verify build: cargo build --release

### Exit Codes

| Code | Meaning |
|------|---------|
| 0 | All checks passed |
| 1 | Checks failed (with fixable issues) |
| 2 | Checks failed (with unfixable issues) |
| 3 | Domain detection failed (unknown project type) |

## Performance Targets

| Level | Target | Max |
|-------|--------|-----|
| File-level | <50ms | <100ms |
| Module-level | <200ms | <500ms |
| Project-level | <2s | <5s |
| Full run | <5s | <10s |

If checks exceed max time, abort and report partial results with warning.