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What are behaviours and why are they important in testing?
Mahnoor FatimaBehaviors in Elixir are the interfaces that are in Object-Oriented Programming. They provide an abstract definition of a module for testing. A behavior typically consists of a set of functions that need to be implemented by the module.
Behaviours ensure that:
- The functions that need to be implemented are defined within the behavior.
- The functions are implemented in the actual module.
In case the function inside a behavior is not implemented, :error is raised.
Example
For instance, we can ensure that certain modules parse strings. For this, we can introduce a Parse behavior, such as the example below:
defmodule @Parse do
@doc '''
Parse a string
'''
@callback parse(String.t) :: {:ok, term} | {:error, String.t}
end
Now this behavior is implemented in a module:
defmodule JSONParser do
@behaviour Parse
@impl Parse
def parse(str), do: {:ok, "some json " <> str} # ... parse JSON
endExplanation
Asserting that the module JSONParser has behavior Parse, we can ensure that the function parse() returns a string. The absence of the function or the wrong return type would have raised an error.
RELATED TAGS
behavior
module
elixir
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