Imported from majiayu000/claude-skill-registry (skills/development/development-stack-standards-bryonjacob-aug/SKILL.md). Install upstream with npx skills add majiayu000/claude-skill-registry --skill development-stack-standards-bryonjacob-aug. Copyright stays with the author.

Development Stack Standards

Reference for creating and assessing language-specific development stacks. Defines what constitutes a complete stack, maturity progression, assessment criteria.

Used by:

• /stack-assess - Grade projects against stack standards
• /stack-guide - Create/validate/customize stack definitions
• Stack skills (configuring-python-stack, configuring-javascript-stack, etc.)

Five-Level Maturity Model

Level 0: Foundation (EVERY project)

Dimensions: 8 required

Justfile recipes: (implements aug-just/justfile-interface Level 0)

• dev-install - Setup environment
• format - Auto-fix formatting
• lint - Auto-fix linting
• typecheck - Static type checking
• test - Run unit tests
• coverage - Measure coverage (any threshold)
• build - Create artifacts
• clean - Remove generated files
• check-all - Run all checks (format → lint → typecheck → coverage)
• default - Show available commands

When: All projects, no exceptions

Assessment:

• All 8 dimensions present?
• All 10 justfile recipes present?
• Can fresh clone execute just dev-install && just check-all?

Level 1: Quality Gates (CI/CD)

Adds: 4 dimensions

Justfile adds:

• test-watch - Continuous testing
• integration-test - Integration tests, no threshold, never blocks
• complexity - Detailed complexity report (informational)
• loc - Largest files by lines of code

Updates:

• coverage - Now enforces 96% threshold for unit tests only
• lint - Now checks complexity ≤10

When: CI/CD pipeline, multiple developers, quality enforcement

Assessment:

• Coverage fails below 96% for unit tests?
• Complexity threshold ≤10 enforced?
• Integration tests marked/tagged?
• Integration tests excluded from coverage threshold?

Level 2: Security & Compliance (Production)

Adds: 4 dimensions

Justfile adds:

• deps - Show outdated packages
• vulns - Scan for vulnerabilities
• lic - Analyze licenses
• sbom - Generate software bill of materials

When: Production deployment, security requirements, compliance needs

Assessment:

• Vulnerability scanner configured?
• License checker present?
• SBOM generation works?
• Dependency update tracking available?

Level 3: Metrics (Large codebases)

Adds: Detailed analysis (already have basic from Level 1)

Justfile: Uses existing complexity and loc from Level 1

When: Refactoring needs, large codebases, technical debt management

Assessment:

• Complexity reporting detailed enough for refactoring decisions?
• LOC tracking identifies largest files?

Level 4: Polyglot (Multi-language)

Structure: Root justfile orchestrates language-specific subprojects

Root commands: Subset (orchestration only)

• dev-install, check-all, clean, build, deps, vulns, lic, sbom
• Delegates to subprojects via _run-all

Subproject commands: Full interface (each implements Level 0+)

When: Multiple languages, monorepo, microservices

Assessment:

• Root orchestrates without duplication?
• Each subproject standalone (cd api && just check-all)?
• _run-all fails fast?

Dimension Specifications

Package Management

Purpose: Reproducible dependency installation

Required capabilities:

• Install dependencies from manifest
• Generate/maintain lockfile
• Isolation (virtual env, node_modules, local Maven repo)

Examples:

• Python: uv (fast, handles venv + install + lock)
• JavaScript: pnpm (fast, efficient, good lockfile)
• Java: Maven (standard, handles everything)

Assessment questions:

• Can fresh clone install dependencies? (just dev-install)
• Is lockfile committed?
• Are dependencies isolated from system?

Config files:

• Python: pyproject.toml, uv.lock
• JavaScript: package.json, pnpm-lock.yaml
• Java: pom.xml, pom.xml.lock (if using Lockfile Plugin)

Code Formatting

Purpose: Consistent style, zero bikeshedding

Required capabilities:

• Auto-fix (modify files in place)
• Deterministic (same input → same output)
• Configurable (line length, indent size)

Examples:

• Python: ruff (fast, opinionated, handles format + lint)
• JavaScript: prettier (standard, works everywhere)
• Java: spotless + Google Java Format (standard for Java)

Assessment questions:

• Does just format succeed?
• Is config file present?
• Does just format change files, then second run changes nothing?

Config files:

• Python: pyproject.toml → [tool.ruff] section
• JavaScript: .prettierrc
• Java: pom.xml → spotless plugin config

Standard settings:

• Line length: 100 (balance readability vs horizontal space)
• Indent: Language default (4 for Python, 2 for JS, 2 for Java)

Linting

Purpose: Catch bugs, enforce patterns

Required capabilities:

• Auto-fix safe changes
• Configurable rules
• Complexity checking (Level 1+)

Examples:

• Python: ruff (fast, handles format + lint + import sort)
• JavaScript: eslint (standard, many plugins)
• Java: spotbugs (static analysis, bug detection)

Assessment questions:

• Does just lint succeed?
• Are rules configured?
• Does lint auto-fix safe issues?
• Is complexity threshold ≤10 enforced? (Level 1+)

Config files:

• Python: pyproject.toml → [tool.ruff] section
• JavaScript: eslint.config.js
• Java: pom.xml → spotbugs + checkstyle plugins

Standard rules:

• Level 0: Error detection, code quality
• Level 1: Add complexity check (≤10)

Type Checking

Purpose: Catch type errors before runtime

Required capabilities:

• Static type analysis
• Strict mode available
• IDE integration (LSP)

Examples:

• Python: mypy (standard, strict mode)
• JavaScript/TypeScript: tsc (built into TypeScript)
• Java: javac (built into compiler)

Assessment questions:

• Does just typecheck succeed?
• Is strict mode enabled?
• Are type annotations required/present?

Config files:

• Python: pyproject.toml → [tool.mypy] with strict = true
• JavaScript: tsconfig.json with strict: true
• Java: pom.xml compiler settings (warnings as errors)

Standard settings:

• Strict mode enabled
• Disallow untyped code
• Treat type errors as failures

Testing

Purpose: Verify correctness, enable refactoring

Required capabilities:

• Unit test execution
• Fast (Level 0: any speed, Level 1: fast subset)
• Watch mode (Level 1+)
• Integration separation (Level 1+)

Examples:

• Python: pytest (standard, powerful, fast)
• JavaScript: vitest (fast, modern, good DX)
• Java: JUnit 5 (standard, modern features)

Assessment questions:

• Tests exist?
• Does just test run unit tests?
• Are unit/integration separated? (Level 1+)
• Does just test-watch work? (Level 1+)

Config files:

• Python: pyproject.toml → [tool.pytest.ini_options] with markers
• JavaScript: vitest.config.ts
• Java: pom.xml → surefire plugin, use JUnit 5 tags

Test organization:

• Level 0: Tests exist, run via just test
• Level 1: Separation (unit fast, integration marked/tagged)
• Marker examples: @pytest.mark.integration, @Tag("integration")

Coverage

Purpose: Measure test completeness

Required capabilities:

• Line/branch/function coverage
• Threshold enforcement
• HTML reports
• Exclude integration tests from threshold (Level 1+)

Examples:

• Python: pytest-cov (pytest plugin)
• JavaScript: vitest coverage (built-in)
• Java: JaCoCo (Maven plugin)

Assessment questions:

• Coverage measured?
• Threshold enforced? (Level 1: 96%)
• Integration tests excluded from threshold? (Level 1+)
• HTML report generated?

Config files:

• Python: pyproject.toml → [tool.coverage.report] with fail_under = 96
• JavaScript: vitest.config.ts → coverage thresholds 96
• Java: pom.xml → JaCoCo plugin with 0.96 minimum

Thresholds:

• Level 0: Coverage measured (any threshold or none)
• Level 1: 96% for unit tests, no threshold for integration

Rationale for 96%:

• High enough to ensure thorough testing
• Allows 4% for legitimately hard-to-test code
• Prevents "get to 100% by testing trivial code" waste

Complexity

Purpose: Limit function complexity, identify refactoring targets

Required capabilities:

• Cyclomatic complexity measurement
• Threshold enforcement (Level 1: ≤10)
• Detailed reporting (file-by-file, avg/max)

Examples:

• Python: radon (detailed reports), ruff (threshold enforcement)
• JavaScript: eslint complexity rule, @pnpm/complexity
• Java: checkstyle (threshold), PMD (detailed reports)

Assessment questions:

• Complexity threshold ≤10 enforced? (Level 1+)
• Detailed reporting available? (Level 3+)
• Are violations caught in just lint?

Config files:

• Python: ruff for threshold, radon for reporting
• JavaScript: eslint.config.js complexity rule, pnpm dlx for reporting
• Java: checkstyle for threshold, PMD for reporting

Thresholds:

• Level 1: Max complexity ≤10 enforced
• Level 3: Detailed reporting for refactoring decisions

Rationale for ≤10:

• Functions with complexity >10 harder to understand and test
• Standard threshold in many style guides
• Encourages small, focused functions

LOC (Lines of Code)

Purpose: Identify large files, track codebase size

Required capabilities:

• Count lines by file
• Sort by size
• Language filtering

Examples:

• Python: pygount (Python ecosystem tool)
• JavaScript: cloc (universal, widely available)
• Java: cloc (universal)

Assessment questions:

• Can identify N largest files?
• Output readable/parseable?

Justfile pattern:

loc N="20":
    @echo "📊 Top {{N}} largest files by LOC:"
    @[language-specific command] | sort -rn | head -{{N}}

Tool choice:

• Ecosystem tool preferred if available and good
• Universal tool (cloc) acceptable
• Any tool that counts accurately

Vulnerability Scanning (Level 2)

Purpose: Identify known security vulnerabilities in dependencies

Required capabilities:

• Scan dependencies for CVEs
• Severity reporting (critical/high/medium/low)
• Exit code on findings

Examples:

• Python: pip-audit (official, comprehensive)
• JavaScript: pnpm audit (built-in)
• Java: dependency-check (OWASP, comprehensive)

Assessment questions:

• Scanner configured?
• Runs in CI? (recommended for Level 2)
• Failures on critical/high vulns?

Justfile recipe:

vulns:
    [scan command]

License Analysis (Level 2)

Purpose: Track dependency licenses, identify compliance issues

Required capabilities:

• List all dependency licenses
• Flag restrictive licenses (GPL, AGPL, etc.)
• Separate prod vs dev dependencies

Examples:

• Python: pip-licenses (summary mode)
• JavaScript: license-checker (pnpm dlx)
• Java: license-maven-plugin (third-party report)

Assessment questions:

• License scanner present?
• Can identify all licenses?
• Flags GPL/restrictive licenses?

Justfile recipe:

lic:
    [license command] --summary

SBOM Generation (Level 2)

Purpose: Software bill of materials for supply chain security

Required capabilities:

• Generate CycloneDX format SBOM
• Include all dependencies
• Output to file

Examples:

• Python: cyclonedx-py
• JavaScript: @cyclonedx/cyclonedx-npm
• Java: cyclonedx-maven-plugin

Assessment questions:

• SBOM generator configured?
• Output CycloneDX format?
• Includes all dependencies?

Justfile recipe:

sbom:
    [sbom generator command] -o sbom.json

Dependency Tracking (Level 2)

Purpose: Track outdated dependencies, enable updates

Required capabilities:

• List outdated packages
• Show current vs latest versions
• Readable output

Examples:

• Python: uv pip list --outdated
• JavaScript: pnpm outdated
• Java: mvn versions:display-dependency-updates

Assessment questions:

• Command shows outdated deps?
• Output shows current vs latest?

Justfile recipe:

deps:
    [outdated command]

Stack Skill Template

Language-specific stack skills follow this structure:

---
name: configuring-[language]-stack
description: [Language] stack - [tools summary] ([coverage threshold])
---

# [Language] Stack

## Standards Compliance

| Standard | Level | Status |
|----------|-------|--------|
| aug-just/justfile-interface | Baseline (Level 0) | ✓ Full |
| development-stack-standards | Level [N] | ✓ Complete |

**Dimensions:** [X]/[Y] ([dimension summary])

## Toolchain

| Tool | Use |
|------|-----|
| **[tool]** | [purpose] |
| ... | ... |

## Quick Reference

```bash
[common commands]

Docker Compatibility

Web services: Bind to 0.0.0.0 (not 127.0.0.1)

[example code for binding]

Standard Justfile Interface

Implements: aug-just/justfile-interface (Level 0 baseline)

[complete justfile for this stack]

Configuration Files

[config-file-name]

[complete config]

Notes

• [Stack-specific guidance]
• [Integration test marking]
• [Coverage threshold notes]

**Required sections:**
1. Frontmatter (name + description)
2. Standards Compliance table
3. Toolchain table
4. Quick reference (bash commands)
5. Docker compatibility
6. Standard justfile interface
7. Configuration files
8. Notes

---

## Assessment Criteria

### Level 0 Assessment

**Dimensions present?** (8/8 required)
- Package manager
- Format
- Lint
- Typecheck
- Test
- Coverage measurement
- Build
- Clean

**Justfile recipes?** (10/10 required)
- All baseline recipes present
- `check-all` dependencies: `format lint typecheck coverage`
- Comments match aug-just/justfile-interface

**Functional?**
- `just dev-install` succeeds
- `just check-all` succeeds or fails meaningfully

### Level 1 Assessment

**All Level 0 complete?** (prerequisite)

**Dimensions added?** (4/4 required)
- Coverage threshold 96% (unit tests only)
- Complexity threshold ≤10
- Test separation (unit vs integration)
- Test watch mode

**Justfile recipes added?** (4/4 required)
- `test-watch`
- `integration-test`
- `complexity`
- `loc`

**Functional?**
- `just coverage` fails below 96%
- `just lint` checks complexity ≤10
- Integration tests marked and excluded from threshold
- `just test-watch` runs continuously

### Level 2 Assessment

**All Level 1 complete?** (prerequisite)

**Dimensions added?** (4/4 required)
- Vulnerability scanning
- License analysis
- SBOM generation
- Dependency tracking

**Justfile recipes added?** (4/4 required)
- `deps`
- `vulns`
- `lic`
- `sbom`

**Functional?**
- Each command succeeds
- Output meaningful and parseable

### Level 3 Assessment

**Uses Level 1 tools** (complexity, loc) for detailed analysis

**Complexity reporting:**
- File-by-file breakdown
- Average and max metrics
- Identifies refactoring targets

**LOC analysis:**
- Identifies largest files
- Sortable output
- Helps scope refactoring

### Level 4 Assessment

**Structure:**
- Root justfile orchestrates
- Subproject justfiles implement full interface
- Each subproject standalone

**Root recipes:**
- Subset only: `dev-install`, `check-all`, `clean`, `build`, `deps`, `vulns`, `lic`, `sbom`
- Delegates via `_run-all`

**Subprojects:**
- Each implements Level 0+ independently
- Can run `cd [subproject] && just check-all`
- Languages follow their stack standards

---

## Tool Selection Guidance

### When ecosystem tool exists and is good

**Use it.** Example: pytest (Python), vitest (JS), Maven (Java)

### When multiple good options exist

**Prefer:**
1. Most widely adopted in ecosystem
2. Best maintained
3. Simplest to configure
4. Fastest

### When ecosystem lacks good option

**Use universal tool.** Example: cloc for LOC across languages

### Avoid

- Abandoned tools
- Tools requiring complex setup
- Tools with poor documentation
- Tools that fight the ecosystem

---

## YAGNI Enforcement

**Stop at the level you need:**

Library (no deployment): 0 → 1 → 2 (stop)

Web app (CI/CD + deploy): 0 → 1 → 2 → maybe 3

Solo project: 0 → 2 (skip quality overhead, add security)

Monorepo: 0 → 1 → 4 → 2 → 3

**Don't add:**
- Level 1 if no CI/CD
- Level 2 if not deploying
- Level 3 if codebase small
- Level 4 if single language

**Do add:**
- Level 0 always
- Levels only when "when" criteria met
- Specific patterns as needed