Gain insights into property-based testing with PropEr in Elixir. Learn foundational principles, custom data generators, and advanced concepts for effective real-world application testing.

Property Based Testing with PropEr in Elixr_468 x 60 copy.png

propert-based-testing.tar.gz

Erlang

Elixer

Erlang-Chap2

Elixir-Chap2

Erlang-Shell

erlang-user

elixir-user

elixir-shell

elrang-eunit

erlang-chap5-employee

elixir-cover_test

erlang-cover_test

erlang-chap10-databaseinit

erlang-chap10-user

elixir-chap10-user

erlang-chap10-shell

elixir-chap10-shell

erlang-chap10-dbsetup

elixir-chap10-dbSetup

erlang-chap5-templating

erlang-chap5-last

elixir-chap5-last

erlang-chap10-default

elixir-chap10-default

elixir-chap10-default-copy

Erlang-Chap2-copy

Elixir-Chap2-copy

Erlang-Shell-copy

elixir-shell-copy

erlang-default-force

elixir-default-force

erlang-test-shell

elxir-test-shell

Property-based testing relies on specifying some property of code, unlike unit tests, which specify the expected output in response to some inputs. In this course, we'll cover the concepts we need to feel confident about using even the most advanced features of PropEr with Elixir.

We'll start with the basic and foundational principles of property-based testing, see what the framework offers us to get started, make our way through thinking in properties, write our own custom data generators, and then learn more advanced concepts. We'll also see how you can use property-based testing in a realistic project.

By the time we finish this course, we should feel comfortable testing real-world applications using properties.

Property-Based Testing with PropEr in Elixir

# Summary
Through properties-driven development, we’ve extrapolated properties from a vague spec and tested our happy paths in a test-first approach. While a useful metric to show whether code has been tested, code coverage isn’t great to assess test quality. We've learned how to compensate using negative testing in a fuzzing-inspired approach, as well as how playing with properties by relaxing constraints can uncover all kinds of bugs and underspecifications that could prove problematic.


# What's next
We’ve done all this while learning about the most complex generators this course contains. We should now have a pretty good idea of what can and can’t be done well with stateless properties. Most of our unit testing needs should now be covered, in fact. Go ahead and utilize what we’ve learned in your own project. As you encounter trickier generators, you might still find them hard to debug. But the next chapter should have you covered, as we will be learning about **shrinking**.

Here's a summary of what we learned in this chapter.

Wrapping Up

Foundations of Property-Based Testing

Writing Properties

Thinking in Properties

Custom Generators

Responsible Testing

Properties-Driven Development

Shrinking

Stateful Properties

Case Study: Bookstore

State Machine Properties

Conclusion

Wrapping Up

Summary