Why is testing is needed

• Whenever as developers, we build any feature we want to make sure it is working so we run it on an actual device to see if it is working. We call this as Manual Testing.

Manual Testing

• Manual testing involves clicking buttons and performing actions to see if the required functionality works.
• It is a reliable form of testing since we can check with human eyes that the flow works.

Problems - involved in manual testing -> Scalability

• When the software grows it becomes harder and harder to test because it is not just the new feature you need to test but also the existing ones.
• We need to test the older working features also because, while building a new feature, there is a high probability that you might have caused a new bug.

Solution - to scalability is -> Automated testing

• Automated tests solve this problem, By just clicking one button we can run a script that runs all the tests and lets us know if it works or not.
• Call it a test suite. It is a collection of test cases.
• We also usually write test cases not just to find the new issues but also to check if the existing code also works after changes to the code.