Spectus

A Ruby testing library that brings precision to your expectations using RFC 2119 compliance levels. 🚥

Quick Start

require "spectus"
require "matchi"

# Define a must-have requirement
test = Spectus.must Matchi::Eq.new(42)
test.call { 42 } # => Pass ✅

# Define an optional feature
test = Spectus.may Matchi::Be.new(:empty?)
test.call { [].empty? } # => Pass ✅

Installation

Add to your Gemfile:

gem "spectus"
gem "matchi" # For matchers

Or install directly:

gem install spectus
gem install matchi

Understanding RFC 2119

Spectus implements RFC 2119 requirement levels to bring clarity and precision to test expectations:

• MUST (✅): Absolute requirement, no exceptions
• SHOULD (⚠️): Strong recommendation with valid exceptions
• MAY (💡): Optional feature

This approach helps you clearly communicate the importance of each test in your suite.

Features

Requirement Levels

Level	Description	Pass Conditions
MUST	Absolute requirement	Only when exact match
SHOULD	Recommended behavior	When matches or has valid reason not to
MAY	Optional feature	When matches or not implemented

Results Classification

• Pass Results:

  • ✅ Success (MUST level met)
  • ⚠️ Warning (SHOULD level met)
  • 💡 Info (MAY level met)

• Fail Results:

  • ❌ Failure (requirement not met)
  • 💥 Error (unexpected exception)

Usage Examples

Testing Required Behavior

test = Spectus.must Matchi::Be.new(1)
test.call { "🦇".size } # Must be exactly 1

Testing Recommended Behavior

test = Spectus.should Matchi::Be.new(0.3)
test.call { 0.1 + 0.2 } # Should be close to 0.3

Testing Optional Features

test = Spectus.may Matchi::Be.new(true)
test.call { [].blank? } # May implement blank? method

Advanced Usage

Click to expand custom matcher example

class PositiveNumber
  def match?
    yield.positive?
  end
end

test = Spectus.must PositiveNumber.new
test.call { 42 } # => Pass

Click to expand integration example

require "spectus"
require "matchi"

RSpec.describe Calculator do
  it "must perform exact arithmetic" do
    test = Spectus.must Matchi::Eq.new(4)
    expect { test.call { 2 + 2 } }.not_to raise_error
  end
end

Related Projects

• Matchi - Collection of compatible matchers
• Test Tube - Underlying test execution engine
• Expresenter - Test result presentation

License

Released under the MIT License.

Support

• Issues: GitHub Issues
• Documentation: RubyDoc
• Blog Post: Fix Article

Sponsors

This project is sponsored by Sashité