fail-fast

fail-fast.rubyforge.org

DESCRIPTION:

FailFast is a collection of assertion methods intended for lightweight contract checking.

FEATURES/PROBLEMS:

TODO More documentation

SYNOPSIS:

def try
  yield
rescue FailFast::AssertionFailureError
  "<Assertion Failure>"
end

include FailFast::Assertions

try { assert(true) }            # => true
try { assert(false) }           # => "<Assertion Failure>"
try { assert(nil) }             # => "<Assertion Failure>"

# We can check multiple values at once
try { assert("foo", :bar, 42) } # => 42
try { assert(1, 2, nil) }       # => "<Assertion Failure>"

# assert_exists only checks for nil-ness - false is OK.
try { assert_exists(true) }     # => true
try { assert_exists(false) }    # => false
try { assert_exists(nil) }      # => "<Assertion Failure>"

# check further constraints after verifying the object is non-nil
try { assert_exists(99) {|n| n > 100 } } # => "<Assertion Failure>"

# Assert that a collection is non-empty
try { assert_one_or_more([1]) }         # => [1]
try { assert_one_or_more(:foo => :bar) } # => {:foo=>:bar}
try { assert_one_or_more([]) }           # => "<Assertion Failure>"

# #deny is the opposite of #assert
try {  deny(true) }             # => "<Assertion Failure>"
try { deny(false) }             # => false
try { deny(nil) }               # => nil

# Assert that an object is hash-like and contains non-nil values for given keys
h = {:foo => 1, :bar => 2, :baz => nil}
try { assert_keys(h, :foo, :bar) } # => {:foo=>1, :bar=>2, :baz=>nil}
try { assert_keys(h, :baz) }       # => "<Assertion Failure>"
try { assert_keys(h, :buz) }       # => "<Assertion Failure>"

# Assert that an object is hash-like and has only the given keys
h = {:foo => 1, :bar => nil}
try { assert_keys(h, :foo, :bar) } # => {:foo => 1, :bar => nil}
try { assert_keys(h, :foo) }       # => "<Assertion Failure>"

REQUIREMENTS:

None!

INSTALL:

sudo gem install fail-fast

LICENSE:

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ‘Software’), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ‘AS IS’, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.