Testing-Notes

Contains notes on software testing.

There are various types of testing, like Unit, Integration and Functional(E2E) testing.

In a gist

Unit Testing -> For testing any small piece of code
Integration Testing -> For testing any small component of the application
Functional Testing -> For testing the complete flow of the application(Basically automating the manual testing/ replicating the user actions)

Generally for testing small piece of code, isolated and alone.
If writing unit test is hard then it means your code is poorly designed. So it also helps in writing better code.
They are also great for preventing regressions - bugs that occur repeatedly.
Unit testing is used in TDD. Its like a backbone.
If an app needs to make a successful database connection then it can't be tested with unit testing.
In procedural code, the units are often functions, in object oriented code, the units are classes.
They are fast + cheap.

Its to test how parts of the system work together - the integration of the parts.
It's similar to unit test with one difference: while unit tests are isolated from other components, integration tests are not.
They are complex and slower compared to unit test.
You should have fewer integration test compared to unit test.
If an app needs to make a successful database connection then it can be tested in integration testing.
They are slow + expensive

Testing the complete functionality of the application by using some tool to automated a browser/mobile.
Do not make them fine-grained, as they can become a nightmare to maintain.
They are used when you want to test a complete flow like registering a user, making a payment and redirecting to proper pages, etc
They are slow + expensive
They require less maintenance and cover a bigger part of your application with saving you a lot of time.

There are three types on android

Similar to local unit tests
Used for testing android specific stuff like activity, fragments, context, serviecs, etc
Need to run on real device or emulator(Roboelectric is used if you don't want to run it on emulator)

Criteria	Espresso	Appium
Language	Java	Many(Java, Python, Javascript, any that can make HTTP request)
Supports	Android Only	Web, Android and iOS
Testing Philosopy	Grey Box	Black Box
Speed	Fast	Slow compared to Espresso
Ease Of Setup	Easy	Hard
Dependencies On Code	Yes	No
Ease Of Writing Tests	Easy for devs	Easy for testers
Backers	Goolge	Open Source
Suitable For	Android devs	Testers/ QA testing Android & iOS apps