solid_assert is a simple implementation of an
assert utility in Ruby. It let you write tests for your assumptions while coding.
Assertions are meant to test conditions about the integrity of your code. You should use them for testing assumptions like the following:
- If the flow reaches here, then this variable has to have this value.
- This line of code should never be executed.
- At this point, this list should contain one entry for each key in this hash.
Notice that assertions shouldn't be used for handling error situations. Use Ruby built-in exception handling for that.
Assertions are typically used in development mode. You might want to disable them in production for performance reasons.
You can enable assertions with
Assertions are disabled by default.
assert for testing conditions. You can optionally provide a message
assert some_string != "some value" assert clients.empty?, "Isn't the clients list empty?"
invariant for testing blocks of code. This comes handy when testing your assumptions requires several lines of code. You can provide an optional message if you want
invariant do one_variable = calculate_some_value other_variable = calculate_some_other_value one_variable > other_variable end
invariant "Lists with different sizes?" do one_variable = calculate_some_value other_variable = calculate_some_other_value one_variable > other_variable end
Create a file named
solid_assert.rb in the
config/initializers dir with the following content:
SolidAssert.enable_assertions unless Rails.env.production?
This way assertions will be disabled in production and enabled in the rest of environments
- Programming with assertions. A great article on assertions. It is about the Java language, but the concepts apply to any programming language.
- There are good references to assertive programming in some classic books like The Pragmatic Programmer From Journeyman to Master, Code Complete and Writing solid code