philiprehberger-assert

Standalone runtime assertion library with chainable matchers for Ruby.

Requirements

Ruby >= 3.1

Installation

Add to your Gemfile:

gem 'philiprehberger-assert'

Then run:

bundle install

Or install directly:

gem install philiprehberger-assert

Usage

require 'philiprehberger/assert'

Basic Assertions

Philiprehberger::Assert.that(42).is_a(Integer)
Philiprehberger::Assert.that('hello').not_blank.matches(/^hel/)

Chainable Matchers

Philiprehberger::Assert.that(age).is_a(Integer).gte(0).lte(150)
Philiprehberger::Assert.that(config).includes_key(:host)
Philiprehberger::Assert.that(items).not_empty

Custom Messages

Philiprehberger::Assert.that(value, 'value must be a positive number').is_a(Integer).gt(0)

Soft Assertions

Collect all failures instead of stopping at the first one:

Philiprehberger::Assert.soft do |a|
  a.call(name).not_blank
  a.call(age).is_a(Integer).gte(0)
  a.call(email).matches(/@/)
end
# raises MultipleFailures with all failed assertions

Preconditions (Design by Contract)

Philiprehberger::Assert.precondition(user.active?, 'user must be active')

API

Method	Description
`Assert.that(value, message = nil)`	Start a chainable assertion
`Assert.soft { \|a\| ... }`	Collect failures, raise at end
`Assert.precondition(condition, message)`	Design by Contract check
`Assertion#is_a(type)`	Assert value is an instance of type
`Assertion#gte(num)`	Assert value >= num
`Assertion#lte(num)`	Assert value <= num
`Assertion#gt(num)`	Assert value > num
`Assertion#lt(num)`	Assert value < num
`Assertion#matches(pattern)`	Assert value matches regex pattern
`Assertion#not_blank`	Assert value is not nil or blank
`Assertion#not_empty`	Assert value is not empty
`Assertion#includes_key(key)`	Assert hash includes key

Development

bundle install
bundle exec rspec      # Run tests
bundle exec rubocop    # Check code style

License

MIT