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Testing Predicate Method Implementation in thoughtbot/guides

This test suite demonstrates the usage of RSpec predicate matchers in Ruby unit testing. It validates a simple boolean method using RSpec’s dynamic predicate matching syntax, showcasing clean and readable test implementation.

Test Coverage Overview

The test suite covers the basic functionality of a Thing class’s predicate method ‘awesome?’.

Key areas tested:

Boolean return value validation
Predicate method behavior
Object instantiation verification

Implementation Analysis

The implementation leverages RSpec’s predicate matcher syntax, converting ‘be_awesome’ into a call to ‘awesome?’. This approach demonstrates idiomatic RSpec testing patterns, utilizing the framework’s built-in predicate method handling.

Technical patterns include:

Dynamic predicate matching
Instance method testing
Boolean assertion verification

Technical Details

Testing infrastructure includes:

RSpec testing framework
Ruby class implementation
Predicate matcher syntax
Single describe block structure
Instance-level test scope

Best Practices Demonstrated

The test exemplifies several RSpec best practices for predicate method testing. It shows proper test isolation, clear method naming, and effective use of RSpec’s expressive syntax. Notable practices include:

Descriptive context naming
Single responsibility principle
Clean test setup
Readable expectation syntax

thoughtbot/guides

testing-rspec/predicate_tests_spec.rb

            
# Class under test:

class Thing
  def awesome?
    true
  end
end

# RSpec test:

describe Thing, "#awesome?" do
  it "is true" do
    thing = Thing.new

    expect(thing).to be_awesome
  end
end