How to contribute to OSS with test

by Kazushige Tominaga

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How to contribute to OSS with test How to contribute to OSS with test

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Kazushige Tominaga Kazushige Tominaga tooooooooomy Github : Twitter : creator of A testing library for PHP legacy products https://github.com/kazu9su https://twitter.com/tooooooooomy https://github.com/kazu9su/functional-tester

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Today I don't talk about... Today I don't talk about... Principle of TDD How important test is! Something like that

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Today I talk about... Today I talk about... Why do I write test? Process of contributing Points of writing test of OSS

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I write test just because I like test :) I write test just because I like test :)

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OK OK

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An example Open Source So ware An example Open Source So ware is... is...

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mastodon mastodon

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One day, I found a spec file... One day, I found a spec file...

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Great Great

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But wait, But wait,

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There are a lot of rules in testing world There are a lot of rules in testing world TDD should test all of methods BDD should test behavior Test only provided public methods included in BDD?

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What is the policy of mastodon? What is the policy of mastodon?

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Let's send a Pull Request! Let's send a Pull Request!

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What is the point? What is the point? Write test just about 1 method Committers can see PR easily Write private methods's test I can find out their testing style explicitly

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Let's see their reactions... Let's see their reactions...

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Looks like my PR perfect Looks like my PR perfect

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OK, so let's go ahead! OK, so let's go ahead!

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There is no immediate harm in these tests but you should know that unit tests should not try to look into private methods or internal variables. The unit test must confirm the public API of the class works, i.e. how other code will use it. The internal implementation of the class is subject to change (refactoring). The perfect refactoring is when you change the code but don't have to touch the tests. With tests like these, they would also have to be modified if the internal implementation changes in the future.

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Finally, I could get usable Finally, I could get usable information from the author. information from the author. PR has already been merged, but don't mind :)

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I completely understand about it I completely understand about it

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Looks Good To Me :) Looks Good To Me :)

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Sample PRs Sample PRs https://github.com/tootsuite/mastodon/pull/6439 https://github.com/tootsuite/mastodon/pull/6446 https://github.com/tootsuite/mastodon/pull/6455 https://github.com/tootsuite/mastodon/pull/6456 https://github.com/tootsuite/mastodon/pull/6500

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Conclusion Conclusion Well-known OSS needs test Communication with committers is the most important Make simple, understandable PR Enjoy testing

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Please introduce me the OSS needs test :) Please introduce me the OSS needs test :)

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Thank you! Thank you!