Elixir Mix EMx 030: Writing Great Unit Tests with Devon Estes
Dec 4, 2018
42:44
Panel:
- Josh Adams
- Charles Max Wood
- Mark Ericksen
Special Guest: Devon Estes In this episode of Elixir Mix, the panel talks with https://twitter.com/devoncestes?lang=en who is a software developer who uses Elixir. He currently resides in Berlin, Germany and has been working there for the past four years. The panelists and the guest talk about https://elixir-lang.org, testing, and much more! Check it out! Show Topics: 0:00 – https://devchat.tv/get-a-coder-job/ 0:49 – Chuck: I am starting a new show called http://thedevrev.com. Check it out http://thedevrev.com Our special guest today is Devon Estes. https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/ is a past episode you’ve been on – check it out https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/ 1:26 – Devon: I am American but live in Berlin, Germany for about 4 years now. I was a freelancer, but now I am at a “real” job now where I am a software developer using https://elixir-lang.org 1:50 – Chuck: Cool! 2:05 – Guest: Something to always talk about testing – it’s evergreen! 2:15 – Chuck: What are the benefits you get from testing and what is your approach? 2:24 – The guest answers the question. 3:53 – Panelist chimes in. 4:18 – Panel: I like playing around and I know when something is terrible. I have to poke around to figure out if I like it or not. I am an exploratory developer. I write a test and it looks great at first but the implementation is terrible or something. 5:54 – Mark comments on developers and how they interact with their code. 7:15 – Mark: How do you approach that? I heard you talking about tests, spikes and other things. 7:22 – Guest: If it is something that is small I will write the test first. If it’s larger I will usually do 2-3 spikes to figure out what is going on. The guest continues with this topic. 8:54 – Panel: I found that over the years I couldn’t do that. 9:21 – Guest: With the topic of testing inhttps://elixir-lang.org I have these “rules” but I break them all the time. Sometimes you get better, cleaner tests out of it if you were to break the rule(s.). Tests are only there for 90% of the time, in my own opinion. Sometimes you have to play around to see what’s going on. 10:36 – Panel: I agree a lot, especially with integrations. 10:49 – Guest. 12:18 – Panel: You have these guidelines or rules and you know when to break those rules. You talked about these specific rules and I thought it was interesting. I was reading through these and I have the same rules but you codified them with examples. Can you walk us through your guidelines? 13:00 – Guest: To be super clear I am talking about unit tests. When I think of testing there is this testing pyramid. 13:52 – Panel. 14:57 – Guest: Like I said, these rules are meant to be broken, if appropriate. 16:39 – Guest continues with unit testing and other types of testing. He talks about easier to more difficult kinds of tests. 17:42 – Guest (continues): Sometimes the tests are accurately true, and sometimes not. It can be easy to get into those traps. Hopefully they will tell you what is expected. 18:25 – Panel: In Ruby, there is a test that would modify your code and remove stuff? Was it Mutant? https://github.com/topics/mutation-testing 19:03 – Guest answers the question. 19:38 – Guest: I don’t know if https://elixir-lang.org has anything like that, yet, but it would be pretty cool. It would be a good idea for someone to take on! 20:00 – Chuck: I have had conversations with a colleague – they both pushed back and talked more about https://www.cypress.io and integrated tests. 21:04 – Chuck: I think it’s interesting to see the different approaches! 21:14 – Guest: We are lucky to have great tooling in https://elixir-lang.org The guest mentions https://wallabyjs.com 24:39 – The guest talks about unit levels. Check it out here! 26:35 – Panel. 26:48 – Chuck: How does it affect my workflow? I like end-to-end tests. The efficiency, if it’s repeating stuff – I don’t care – as long as it’s fast enough. If it ruins my workflow then it’s a problem. 27:22 – Panel. 28:12 – The topic “test coverage” is mentioned by Chuck. 28:25 – Panel. 29:02 – https://www.freshbooks.com 30:10 – Guest talks about Wallaby.js. 32:24 – Panel: We’ve had you on before, and the idea is that you are all into Elixir and its path. (https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/) 32:57 – Guest: I think testing in Elixir is simpler. 34:04 – Panel. 34:07 – Guest: You have commands and you have queries. The guest gives a hypothetical example! The guest also mentionshttps://elixir-lang.org/getting-started/mix-otp/genserver.html, too. 35:42 – Guest: There are two ways that you can interact with the process: command & queries. 37:00 – Guest talks about different libraries such as: https://github.com/mox-project/. 37:41 – Panel: Any tips on testing the servers; just any GenServer? 38:25 – Panelist shares his approach with this. 39:54 – Guest: I don’t test name servers b/c they are by definition global state. The guest goes into great detail about testing – check it out! 46:29 – Panel. 47:01 – https://github.com/devonestes I kind of hate the term dependency interjection in the functional context. 47:17 – Panel: I think it’s helpful, because... 47:28 – Guest. 47:49 – Panelists go back-and-forth! 48:20 – Panel: Sending a message to the testing process – this was something that was stated by Devon earlier. I find this really helpful. 49:00 – Chuck: Picks! 49:05 – https://www.lootcrate.com END – https://www.cachefly.com Links:
- https://www.ruby-lang.org/en/
- https://elixir-lang.org
- https://elixir-lang.org/getting-started/mix-otp/genserver.html
- https://elm-lang.org
- https://www.javascript.com
- https://code.visualstudio.com
- https://reactjs.org
- https://wallabyjs.com
- https://www.cypress.io
- https://github.com/topics/mutation-testing
- https://github.com/mox-project/
- https://devchat.tv/ruby-rogues/my-ruby-story-devon-c-estes/
- https://devchat.tv/ruby-rogues/rr-295-the-european-ruby-community-with-devon-c-estes/
- https://devchat.tv/ruby-rogues/rr-330-functions-vs-methods-devon-estes/
- https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/
- https://github.com/devonestes
- https://twitter.com/devoncestes?lang=en
Sponsors:
- https://www.lootcrate.com
- https://devchat.tv/get-a-coder-job/
- https://www.freshbooks.com
- https://www.cachefly.com
Picks: Mark
- https://brainlid.org/dev/2018/11/13/git-aliases.html
- Blog - Mox
Josh
- https://gitpitch.com
- Slide Deck by Josh
Charles
- Values
-
Become a supporter of this podcast: https://www.spreaker.com/podcast/elixir-mix--6102049/support.
- Josh Adams
- Charles Max Wood
- Mark Ericksen
Special Guest: Devon Estes In this episode of Elixir Mix, the panel talks with https://twitter.com/devoncestes?lang=en who is a software developer who uses Elixir. He currently resides in Berlin, Germany and has been working there for the past four years. The panelists and the guest talk about https://elixir-lang.org, testing, and much more! Check it out! Show Topics: 0:00 – https://devchat.tv/get-a-coder-job/ 0:49 – Chuck: I am starting a new show called http://thedevrev.com. Check it out http://thedevrev.com Our special guest today is Devon Estes. https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/ is a past episode you’ve been on – check it out https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/ 1:26 – Devon: I am American but live in Berlin, Germany for about 4 years now. I was a freelancer, but now I am at a “real” job now where I am a software developer using https://elixir-lang.org 1:50 – Chuck: Cool! 2:05 – Guest: Something to always talk about testing – it’s evergreen! 2:15 – Chuck: What are the benefits you get from testing and what is your approach? 2:24 – The guest answers the question. 3:53 – Panelist chimes in. 4:18 – Panel: I like playing around and I know when something is terrible. I have to poke around to figure out if I like it or not. I am an exploratory developer. I write a test and it looks great at first but the implementation is terrible or something. 5:54 – Mark comments on developers and how they interact with their code. 7:15 – Mark: How do you approach that? I heard you talking about tests, spikes and other things. 7:22 – Guest: If it is something that is small I will write the test first. If it’s larger I will usually do 2-3 spikes to figure out what is going on. The guest continues with this topic. 8:54 – Panel: I found that over the years I couldn’t do that. 9:21 – Guest: With the topic of testing inhttps://elixir-lang.org I have these “rules” but I break them all the time. Sometimes you get better, cleaner tests out of it if you were to break the rule(s.). Tests are only there for 90% of the time, in my own opinion. Sometimes you have to play around to see what’s going on. 10:36 – Panel: I agree a lot, especially with integrations. 10:49 – Guest. 12:18 – Panel: You have these guidelines or rules and you know when to break those rules. You talked about these specific rules and I thought it was interesting. I was reading through these and I have the same rules but you codified them with examples. Can you walk us through your guidelines? 13:00 – Guest: To be super clear I am talking about unit tests. When I think of testing there is this testing pyramid. 13:52 – Panel. 14:57 – Guest: Like I said, these rules are meant to be broken, if appropriate. 16:39 – Guest continues with unit testing and other types of testing. He talks about easier to more difficult kinds of tests. 17:42 – Guest (continues): Sometimes the tests are accurately true, and sometimes not. It can be easy to get into those traps. Hopefully they will tell you what is expected. 18:25 – Panel: In Ruby, there is a test that would modify your code and remove stuff? Was it Mutant? https://github.com/topics/mutation-testing 19:03 – Guest answers the question. 19:38 – Guest: I don’t know if https://elixir-lang.org has anything like that, yet, but it would be pretty cool. It would be a good idea for someone to take on! 20:00 – Chuck: I have had conversations with a colleague – they both pushed back and talked more about https://www.cypress.io and integrated tests. 21:04 – Chuck: I think it’s interesting to see the different approaches! 21:14 – Guest: We are lucky to have great tooling in https://elixir-lang.org The guest mentions https://wallabyjs.com 24:39 – The guest talks about unit levels. Check it out here! 26:35 – Panel. 26:48 – Chuck: How does it affect my workflow? I like end-to-end tests. The efficiency, if it’s repeating stuff – I don’t care – as long as it’s fast enough. If it ruins my workflow then it’s a problem. 27:22 – Panel. 28:12 – The topic “test coverage” is mentioned by Chuck. 28:25 – Panel. 29:02 – https://www.freshbooks.com 30:10 – Guest talks about Wallaby.js. 32:24 – Panel: We’ve had you on before, and the idea is that you are all into Elixir and its path. (https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/) 32:57 – Guest: I think testing in Elixir is simpler. 34:04 – Panel. 34:07 – Guest: You have commands and you have queries. The guest gives a hypothetical example! The guest also mentionshttps://elixir-lang.org/getting-started/mix-otp/genserver.html, too. 35:42 – Guest: There are two ways that you can interact with the process: command & queries. 37:00 – Guest talks about different libraries such as: https://github.com/mox-project/. 37:41 – Panel: Any tips on testing the servers; just any GenServer? 38:25 – Panelist shares his approach with this. 39:54 – Guest: I don’t test name servers b/c they are by definition global state. The guest goes into great detail about testing – check it out! 46:29 – Panel. 47:01 – https://github.com/devonestes I kind of hate the term dependency interjection in the functional context. 47:17 – Panel: I think it’s helpful, because... 47:28 – Guest. 47:49 – Panelists go back-and-forth! 48:20 – Panel: Sending a message to the testing process – this was something that was stated by Devon earlier. I find this really helpful. 49:00 – Chuck: Picks! 49:05 – https://www.lootcrate.com END – https://www.cachefly.com Links:
- https://www.ruby-lang.org/en/
- https://elixir-lang.org
- https://elixir-lang.org/getting-started/mix-otp/genserver.html
- https://elm-lang.org
- https://www.javascript.com
- https://code.visualstudio.com
- https://reactjs.org
- https://wallabyjs.com
- https://www.cypress.io
- https://github.com/topics/mutation-testing
- https://github.com/mox-project/
- https://devchat.tv/ruby-rogues/my-ruby-story-devon-c-estes/
- https://devchat.tv/ruby-rogues/rr-295-the-european-ruby-community-with-devon-c-estes/
- https://devchat.tv/ruby-rogues/rr-330-functions-vs-methods-devon-estes/
- https://devchat.tv/elixir-mix/emx-018-devon-estes-all-in-on-elixir/
- https://github.com/devonestes
- https://twitter.com/devoncestes?lang=en
Sponsors:
- https://www.lootcrate.com
- https://devchat.tv/get-a-coder-job/
- https://www.freshbooks.com
- https://www.cachefly.com
Picks: Mark
- https://brainlid.org/dev/2018/11/13/git-aliases.html
- Blog - Mox
Josh
- https://gitpitch.com
- Slide Deck by Josh
Charles
- Values
-
Become a supporter of this podcast: https://www.spreaker.com/podcast/elixir-mix--6102049/support.