# Groovy Coding Practices

> Use when authoring or reviewing Groovy, idiomatic syntax (no semicolons, POGOs, GDK, GStrings), with/tap, Groovy truth and safe nav, strong public typing, and CodeNarc/npm-groovy-lint in CI.

- Skill: `ryan-brosas/groovy-coding-practices` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ryan-brosas/groovy-coding-practices`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ryan-brosas/groovy-coding-practices/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ryan-brosas (https://skillmd.com/u/ryan-brosas)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/ryan-brosas/groovy-coding-practices

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# Groovy Coding Practices

Application skill for Groovy style learning (from the archived `awesome-guidelines` style capsules). For Grails-specific conventions, combine with stack capsules in `skills/*-foundation` and project CodeNarc rulesets.

## Core Principle

Groovy quality is **idiomatic expressiveness with typed public seams**, GDK and property syntax internally, explicit types on shared API.

## When to Use / NOT

- Groovy scripts, Gradle plugins, Grails apps, JVM automation libraries.
- Setting up CodeNarc, npm-groovy-lint, Spock tests in CI.

**NOT when:**

- Pure Java/Kotlin modules, use language-specific practice skills.
- Generated AST/transform output, validate generators.

## Workflow

1. **Syntax**, semicolons, def, parens, strings (`groovy-style-syntax-idioms.md`).
2. **Objects**, POGOs, with/tap, equality (`groovy-style-objects-properties.md`).
3. **Collections**, GDK, truth, nav (`groovy-style-collections-gdk.md`).
4. **API**, public typing, assert (`groovy-style-typing-api.md`).
5. **Verify**, CodeNarc/npm-groovy-lint, compile, tests on changed sources.

## Red Flags

- Semicolons on every line
- `def String` / `def` constructors
- Redundant `public` everywhere
- `each() { }` with empty parens
- Manual getter/setter boilerplate on POGOs
- String `+` where GString fits
- Nested null checks vs `?.`
- `==` for reference identity
- Untyped public `def` methods
- Accidental return from assignment in `def` methods
- Java `.class` literals where unnecessary
- Obsolete `Vector`/`Hashtable`
- Blanket `catch (any)` without justification

## Verification

- CodeNarc / npm-groovy-lint (project ruleset)
- `./gradlew compileGroovy` or project build
- Spock/JUnit tests on changed modules
- Capsule checklist on public method signatures


## References

- `awesome-guidelines/references/groovy-style-learning-note.md`
- `awesome-guidelines/references/groovy-style-syntax-idioms.md`
- `awesome-guidelines/references/groovy-style-objects-properties.md`
- `awesome-guidelines/references/groovy-style-collections-gdk.md`
- `awesome-guidelines/references/groovy-style-typing-api.md`