Testing Patterns

What it does

When your agent uses it

• Adding test coverage
• Creating fixtures

Example prompts

• “Use the testing-patterns skill to write Minitest tests with fixtures following 37signals conventions”
• “/testing-patterns”

Requirements

• Compatibility (from SKILL.md): Ruby 3.3+, Rails 8.0+, Minitest

What it can do on your machine

Read from SKILL.md and the folder at commit 0ef5e5d. 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

  Shell commands in SKILL.md call:

  • rails

  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.

• Compatibility

  Ruby 3.3+, Rails 8.0+, Minitest

  From compatibility in the SKILL.md frontmatter.

Context cost

Testing Patterns loads about 1.4k tokens when it runs, and up to ~4.8k if it reads all its reference files. Until then it costs about 89 tokens; SKILL.md has 241 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~89

When it runs · the whole SKILL.md, loaded when a task matches

~1.4k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~4.8k

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

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 dilolabs/nosia at commit 0ef5e5d, republished under its MIT licence (© dilolabs). 241 words, ~1,383 tokens.

name

testing-patterns

description

Writes Minitest tests with fixtures following 37signals conventions. Uses Minitest (not RSpec) and fixtures (not factories). Use when writing tests, adding test coverage, or creating fixtures. WHEN NOT: For RSpec or FactoryBot patterns (this project uses Minitest + fixtures exclusively). For test configuration/CI setup (see project docs).

compatibility

Ruby 3.3+, Rails 8.0+, Minitest

license

MIT

require "test_helper"

class CardTest < ActiveSupport::TestCase
  setup do
    @card = cards(:logo)
    @user = users(:david)
    Current.user = @user
    Current.account = @card.account
  end

  teardown do
    Current.reset
  end

  test "fixtures are valid" do
    assert @card.valid?
  end

  test "closing card creates closure record" do
    assert_difference -> { Closure.count }, 1 do
      @card.close(user: @user)
    end
    assert @card.closed?
    assert_equal @user, @card.closed_by
  end

  test "open scope excludes closed cards" do
    @card.close
    assert_not_includes Card.open, @card
    assert_includes Card.closed, @card
  end
end

require "test_helper"

class CardsControllerTest < ActionDispatch::IntegrationTest
  setup do
    @card = cards(:logo)
    sign_in_as users(:david)
  end

  test "should create card" do
    assert_difference -> { Card.count }, 1 do
      post board_cards_path(@card.board), params: {
        card: { title: "New card", column_id: @card.column_id }
      }
    end
    assert_redirected_to card_path(Card.last)
  end

  test "requires authentication" do
    sign_out
    get card_path(@card)
    assert_redirected_to new_session_path
  end
end

# test/test_helper.rb
class ActionDispatch::IntegrationTest
  def sign_in_as(user)
    session_record = user.identity.sessions.create!
    cookies.signed[:session_token] = session_record.token
    Current.user = user
    Current.identity = user.identity
    Current.session = session_record
  end

  def sign_out
    cookies.delete(:session_token)
    Current.reset
  end
end

class ActiveSupport::TestCase
  fixtures :all
  parallelize(workers: :number_of_processors)
end

# Record count changes
assert_difference -> { Card.count }, 1 do ... end

# Attribute updates
@card.close
assert @card.closed?
assert_equal @user, @card.closed_by

# Errors
assert_raises ActiveRecord::RecordInvalid do
  Card.create!(title: nil)
end

# Collections
assert_includes Card.open, @card
refute_includes Card.closed, @card

# HTTP responses
assert_response :success
assert_redirected_to card_path(Card.last)

# DOM assertions
assert_select "h1", "Cards"
assert_select ".card", count: 3

# Jobs and emails
assert_enqueued_with job: NotifyRecipientsJob do ... end
assert_emails 1 do ... end

# BAD: Using factories
let(:card) { FactoryBot.create(:card) }
# GOOD: Use fixtures
setup { @card = cards(:logo) }

# BAD: Testing implementation
test "calls create_closure" do
  @card.expects(:create_closure!)
  @card.close
end
# GOOD: Test behavior
test "closing creates closure" do
  @card.close
  assert @card.closed?
end

# BAD: Creating data when fixtures exist
setup { @user = User.create!(name: "Test") }
# GOOD: Use fixtures
setup { @user = users(:david) }

# BAD: Testing Rails functionality
test "validates presence of title" do ...
# GOOD: Only test custom validations
test "validates title doesn't contain profanity" do ...

© dilolabs, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files (references) in .vibe/skills/testing-patterns of dilolabs/nosia.

• SKILL.md
• references/controller-tests.md
• references/fixture-patterns.md
• references/system-tests.md

Open the folder on GitHubat commit 0ef5e5d

Used in 1 other repository

We found 3 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in dilolabs/nosia, which our catalogue first saw on October 7, 2026.

• ThibautBaissac/rails_ai_agents.claude_37signals/skills/testing-patterns