72: TypeCheck with Wiebe-Marten Wijnja

We talk with Wiebe-Marten Wijnja about his project TypeCheck that provides a new kind of runtime type checking for Elixir applications. The syntax builds on your existing spec types so it still works for dialyzer but adds additional compile time created checks. It also works for generating property based test data. This feature comes out in a new ability called "spectest". Like doctests, you can have automated checks that verify the function adheres to the spec! We also cover how TypeCheck allows writing type declarations for other libraries like Ecto and Plug. There are some interesting ways for people to contribute! A very interesting library!

Show Notes online - http://podcast.thinkingelixir.com/72

Elixir Community News

• https://twitter.com/erlang_org/status/1453018514617475074 – Ericsson OTP Team announced the launch of the brand new Erlang Forums
• https://hello.erlangforums.com – New Erlang Forum
• https://github.com/elixir-lang/elixir/releases/tag/v1.13.0-rc.0 – Elixir 1.13 RC was released
• https://twitter.com/wojtekmach/status/1453671121820192770 – Ability to globally customize inspect.
• https://groups.google.com/g/elixir-lang-core/c/LYmkUopaWN4/m/SwBzRt2zBQAJ – Mailing list discussion
• https://github.com/elixir-lang/elixir/pull/11349 – PR discussion
• https://twitter.com/tylerayoung/status/1454780291374096384 – Tyler Young's comment thread about the process
• https://twitter.com/livebookdev/status/1455236497960013836 – Livebook 0.3 released
• https://www.youtube.com/watch?v=4lNkiACemM0 – Jose Valim's video demonstrating new features

Do you have some Elixir news to share? Tell us at @ThinkingElixir or email at [email protected]

Discussion Resources

• https://github.com/Qqwy/elixir-type_check – TypeCheck GitHub repo
• https://hexdocs.pm/type_check/type-checking-and-spec-testing-with-typecheck.html – Introductory article
• https://elixirforum.com/t/typecheck-fast-and-flexible-runtime-type-checking-for-your-elixir-projects/32886 – Forum topic with many examples and updates
• https://hexdocs.pm/type_check/comparing-typecheck-and-norm.html – Comparison with Norm
• https://twitter.com/strzibnyj/status/1438393349644464130
• https://hexdocs.pm/type_check/comparing-typecheck-and-elixir-typespecs.html – Feature-parity of TypeCheck with Elixir's builtin typespecs
• https://www.youtube.com/watch?v=6sNmJtoKDCo – Clarity - Saša Jurić - ElixirConf EU 2021
• https://racket-lang.org/

Guest Information

• https://twitter.com/wiebemarten – on Twitter
• https://github.com/Qqwy/ – on Github
• https://wmcode.nl/ – Personal site
• https://resilia.nl/ – Work site

Find us online

• Message the show - @ThinkingElixir
• Email the show - [email protected]
• Mark Ericksen - @brainlid
• David Bernheisel - @bernheisel
• Cade Ward - @cadebward