Agent skill

Rails Testing

Ruby on Rails testing best practices for writing effective, maintainable test suites with RSpec.

MITAuto-check passedTesting & QA

Install Rails Testing

skills CLI

$ npx skills add pproenca/dot-skills --skill rails-testing -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills rails-testing --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/.curated/rails-testing .claude/skills/rails-testing && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "rails-testing" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing into .claude/skills/rails-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rails-testing", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add pproenca/dot-skills --skill rails-testing -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills rails-testing --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/.curated/rails-testing .agents/skills/rails-testing && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "rails-testing" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing into .agents/skills/rails-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rails-testing", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add pproenca/dot-skills --skill rails-testing -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills rails-testing --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/.curated/rails-testing .cursor/skills/rails-testing && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "rails-testing" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing into .cursor/skills/rails-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rails-testing", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/pproenca/dot-skills.git --path skills/.curated/rails-testing

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add pproenca/dot-skills --skill rails-testing -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills rails-testing --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/.curated/rails-testing .gemini/skills/rails-testing && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "rails-testing" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing into .gemini/skills/rails-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rails-testing", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install pproenca/dot-skills rails-testing

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add pproenca/dot-skills --skill rails-testing -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/.curated/rails-testing .github/skills/rails-testing && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "rails-testing" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing into .github/skills/rails-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rails-testing", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add pproenca/dot-skills --skill rails-testing -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills rails-testing --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/.curated/rails-testing .opencode/skills/rails-testing && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "rails-testing" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.curated/rails-testing into .opencode/skills/rails-testing/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "rails-testing", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: rails-testing
GitHub stars: 214
Token cost: ~2.1k tokens
SKILL.md length: 604 words
Files: 51 (incl. references, assets)
Skills in repo: 182
Repo updated: Aug 15, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Ruby on Rails testing best practices for writing effective, maintainable test suites with RSpec.

Works in 8 steps: Test Design & Structure (CRITICAL) → Test Data Management (CRITICAL) → Model Testing (HIGH) → …
Tasks involving RSpec specs
SKILL.md covers When to Apply, Rule Categories by Priority, Quick Reference and How to Use, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Rails Testing is an agent skill from pproenca/dot-skills. Ruby on Rails testing best practices for writing effective, maintainable test suites with RSpec. This skill should be used when writing, reviewing, or refactoring Rails tests to ensure proper test design, data management, and coverage patterns. Triggers on tasks involving RSpec specs, model tests, request specs, system tests, factory definitions, Capybara interactions, Sidekiq job tests, or test suite optimization. Complementary to rails-dev, ruby-optimise, and ruby-refactor skills.

Its SKILL.md is about 2.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 53 other files, including reference files and assets (for example `AGENTS.md`, `assets/templates/_template.md` and `metadata.json`).

It sits in Testing & QA, covering Backend development, Test generation and Refactoring. It works with Ruby on Rails and Ruby. The repository describes itself as: A collection of AI agent skills following the Agent Skills open format. The licence is MIT.

When your agent uses it

Tasks involving RSpec specs
Factory definitions
Capybara interactions
Sidekiq job tests

Example prompts

“/rails-testing”

Workflow steps

8 steps, taken from the step headings in SKILL.md.

Test Design & Structure (CRITICAL)
Test Data Management (CRITICAL)
Model Testing (HIGH)
Request & Controller Testing (HIGH)
System & Acceptance Testing (MEDIUM-HIGH)
Async & Background Job Testing (MEDIUM)
Test Performance & Reliability (MEDIUM)
Test Organization & Maintenance (LOW-MEDIUM)

What it can do on your machine

Read from SKILL.md and the folder at commit cf93c57. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Rails Testing loads about 2.1k tokens when it runs, and up to ~35k if it reads all its reference files. Until then it costs about 125 tokens; SKILL.md has 604 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~125
When it runs · the whole SKILL.md, loaded when a task matches: ~2.1k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~35k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from pproenca/dot-skills at commit cf93c57, republished under its MIT licence (© pproenca). 604 words, ~2,127 tokens.

Download SKILL.mdSave it as .claude/skills/rails-testing/SKILL.md (or your agent's skills folder). This skill also uses 50 other files; get the full folder from GitHub.

name: rails-testing
description: Ruby on Rails testing best practices for writing effective, maintainable test suites with RSpec. This skill should be used when writing, reviewing, or refactoring Rails tests to ensure proper test design, data management, and coverage patterns. Triggers on tasks involving RSpec specs, model tests, request specs, system tests, factory definitions, Capybara interactions, Sidekiq job tests, or test suite optimization. Complementary to rails-dev, ruby-optimise, and ruby-refactor skills.

Community Ruby on Rails Testing Best Practices

Comprehensive testing guide for Ruby on Rails applications, maintained by Community. Contains 46 rules across 8 categories, prioritized by impact to guide automated test generation, review, and refactoring.

When to Apply

Reference these guidelines when:

Writing new RSpec specs for models, requests, system tests, or jobs
Setting up FactoryBot factories with traits and sequences
Writing Capybara system tests for user journeys
Testing background jobs with Sidekiq or Active Job
Reviewing test code for anti-patterns (mystery guests, flaky tests, slow specs)
Optimizing test suite performance and CI pipeline speed
Organizing test files, shared examples, and custom matchers

Rule Categories by Priority

Priority	Category	Impact	Prefix
1	Test Design & Structure	CRITICAL	`design-`
2	Test Data Management	CRITICAL	`data-`
3	Model Testing	HIGH	`model-`
4	Request & Controller Testing	HIGH	`request-`
5	System & Acceptance Testing	MEDIUM-HIGH	`system-`
6	Async & Background Job Testing	MEDIUM	`async-`
7	Test Performance & Reliability	MEDIUM	`perf-`
8	Test Organization & Maintenance	LOW-MEDIUM	`org-`

Quick Reference

1. Test Design & Structure (CRITICAL)

design-four-phase-test - Use four-phase test structure (setup, exercise, verify, teardown)
design-behavior-over-implementation - Test observable behavior, not internal implementation
design-one-assertion-per-test - One logical expectation per test for precise failure diagnosis
design-descriptive-test-names - Write test names that read like specifications
design-avoid-mystery-guest - Make all test data visible within the test itself
design-avoid-conditional-logic - No if/else or loops in test code
design-explicit-subject - Name subjects explicitly instead of using implicit subject

2. Test Data Management (CRITICAL)

data-factory-traits - Use composable factory traits instead of separate factories
data-minimal-attributes - Specify only attributes relevant to the test
data-build-over-create - Prefer build/build_stubbed over create when persistence isn't needed
data-avoid-fixture-coupling - Use factories instead of shared fixtures
data-transient-attributes - Use transient attributes for complex factory setup
data-sequence-unique-values - Use sequences for uniqueness-constrained fields

3. Model Testing (HIGH)

model-test-validations - Test validations with boundary cases, not just happy path
model-test-associations - Test associations explicitly including dependent behavior
model-test-scopes - Test scopes with matching and non-matching records
model-test-callbacks-sparingly - Test callback side effects, not callback existence
model-test-custom-methods - Test public methods with input/output pairs across scenarios
model-avoid-testing-framework - Don't test ActiveRecord or framework behavior
model-test-enums - Test enum transitions and generated scopes

Show full SKILL.md (265 more words)Show less

4. Request & Controller Testing (HIGH)

request-over-controller-specs - Use request specs over deprecated controller specs
request-test-response-status - Assert HTTP status codes explicitly
request-test-authentication - Test authentication boundaries for every protected endpoint
request-test-authorization - Test authorization for each role
request-test-params-validation - Test parameter validation and edge cases
request-json-response-structure - Assert JSON response structure for API endpoints

5. System & Acceptance Testing (MEDIUM-HIGH)

system-page-objects - Encapsulate page interactions in page objects
system-use-accessible-selectors - Use accessible selectors over CSS/XPath
system-avoid-sleep - Never use sleep — rely on Capybara's built-in waiting
system-test-critical-paths - Reserve system tests for critical user journeys
system-database-state - Use truncation strategy for system test database cleanup
system-screenshot-on-failure - Capture screenshots on system test failure

6. Async & Background Job Testing (MEDIUM)

async-separate-enqueue-from-perform - Test enqueue and perform separately
async-use-fake-mode-default - Default to Sidekiq fake mode globally
async-test-job-perform - Test job perform method directly
async-test-mailer-delivery - Test mailer delivery with enqueued mail matcher
async-test-after-commit - Account for transaction-aware job enqueuing in Rails 7.2+

7. Test Performance & Reliability (MEDIUM)

perf-parallel-tests - Run tests in parallel across CPU cores
perf-database-strategy - Use transaction strategy for non-system tests
perf-profile-slow-specs - Profile and fix the slowest specs
perf-quarantine-flaky-tests - Quarantine flaky tests instead of retrying
perf-avoid-before-all-mutation - Never mutate state created in before(:all)

8. Test Organization & Maintenance (LOW-MEDIUM)

org-avoid-deep-nesting - Limit context nesting to 3 levels
org-shared-examples-sparingly - Use shared examples only for true behavioral contracts
org-custom-matchers - Extract custom matchers for repeated domain assertions
org-file-structure-mirrors-app - Mirror app directory structure in spec directory

How to Use

Read individual reference files for detailed explanations and code examples:

Section definitions - Category structure and impact levels
Rule template - Template for adding new rules

Reference Files

File	Description
references/_sections.md	Category definitions and ordering
assets/templates/_template.md	Template for new rules
metadata.json	Version and reference information

Files

SKILL.md and 50 other files (references, assets) in skills/.curated/rails-testing of pproenca/dot-skills.

SKILL.md
AGENTS.md
assets/templates/_template.md
metadata.json
references/_sections.md
references/async-separate-enqueue-from-perform.md
references/async-test-after-commit.md
references/async-test-job-perform.md
references/async-test-mailer-delivery.md
references/async-use-fake-mode-default.md
references/data-avoid-fixture-coupling.md
references/data-build-over-create.md
references/data-factory-traits.md
references/data-minimal-attributes.md
references/data-sequence-unique-values.md
references/data-transient-attributes.md
references/design-avoid-conditional-logic.md
references/design-avoid-mystery-guest.md
… and 33 more

Open the folder on GitHubat commit cf93c57

Compare with similar skills

Rails Testing next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Rails Testing compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Rails Testing this skillpproenca/dot-skills	214	—	~2.1k	Automated safety check: Pass	MIT	1 mo ago
Testing Patternsdilolabs/nosia	213	1 repos	~1.4k	Automated safety check: Pass	MIT	28 days ago
Antipattern Preventiondoorkeeper-gem/doorkeeper	5.5k	—	~1.1k	Automated safety check: Pass	MIT	yesterday
Rubyericrisco/rsc-harness	156	—	~3.2k	Automated safety check: Pass	MIT	yesterday
Spring Boot Test Patternsgiuseppe-trisciuoglio/developer-kit	355	—	~2.3k	Automated safety check: Notes	MIT	27 days ago
Java Regression Test GeneratorArabelaTso/Skills-4-SE	253	—	~4k	Automated safety check: Pass	Apache-2.0	1 mo ago

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Questions about Rails Testing

What does Rails Testing do?

Ruby on Rails testing best practices for writing effective, maintainable test suites with RSpec. Rails Testing is an agent skill from pproenca/dot-skills. Ruby on Rails testing best practices for writing effective, maintainable test suites with RSpec.

When should I use Rails Testing?

Rails Testing fits situations like: tasks involving RSpec specs; factory definitions; capybara interactions; sidekiq job tests.

How do I install Rails Testing in Claude Code?

Run `npx skills add pproenca/dot-skills --skill rails-testing -a claude-code`. Or copy the skill folder (skills/.curated/rails-testing in pproenca/dot-skills) into .claude/skills/rails-testing in your project. Claude Code loads it when a task matches its description.

How do I install Rails Testing in Codex?

Run `npx skills add pproenca/dot-skills --skill rails-testing -a codex`. Or copy the skill folder (skills/.curated/rails-testing in pproenca/dot-skills) into .agents/skills/rails-testing in your project. Codex loads it when a task matches its description.

Can I use Rails Testing in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add pproenca/dot-skills --skill rails-testing -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/rails-testing, .gemini/skills/rails-testing, .github/skills/rails-testing and .opencode/skills/rails-testing in your project.

What does Rails Testing need to run?

SKILL.md names no scripts, command-line tools or credentials: Rails Testing is instructions for the agent only.

Does Rails Testing access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Rails Testing safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Rails Testing use?

Rails Testing is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Rails Testing use?

About 2.1k tokens (SKILL.md is roughly 8.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 33k tokens, read only when the agent opens those files.

What are the alternatives to Rails Testing?

Skills that share tags, products or a category with Rails Testing: Testing Patterns (dilolabs/nosia, 213 stars), Antipattern Prevention (doorkeeper-gem/doorkeeper, 5.5k stars), Ruby (ericrisco/rsc-harness, 156 stars) and Spring Boot Test Patterns (giuseppe-trisciuoglio/developer-kit, 355 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Rails Testing?

pproenca (a GitHub user) maintains it in pproenca/dot-skills, which has 214 GitHub stars. The repository holds 182 skills in this directory. The repository was last updated on August 15, 2026.

Source: pproenca/dot-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Rails Testing

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Community Ruby on Rails Testing Best Practices

When to Apply

Rule Categories by Priority

Quick Reference

1. Test Design & Structure (CRITICAL)

2. Test Data Management (CRITICAL)

3. Model Testing (HIGH)

4. Request & Controller Testing (HIGH)

5. System & Acceptance Testing (MEDIUM-HIGH)

6. Async & Background Job Testing (MEDIUM)

7. Test Performance & Reliability (MEDIUM)

8. Test Organization & Maintenance (LOW-MEDIUM)

How to Use

Reference Files

Files

Compare with similar skills

Similar skills

More from pproenca/dot-skills

Related

Questions about Rails Testing