flutter-testing-course

Application developed while doing the Flutter testing course by Richa HarSivo on Udemy.

Notes

Flutter Testing

• Automated test written by developers to ensure app performs correctly before you publish it.
• The more test you write, the more stronge, robust and bug free your code becomes.

Why write tests?

• I’m paid to write code, not tests. A good programmer writes a clean and testable coce which is not possible without writing tests.
• I have tight deadlines. Once you learn how to write tests, it makes development moves faster.
• We already have testers, why do we need to write tests? Testers don’t know the code better than developers. You can safeguard your code from any edge cases.
• Clean Code = Testable Code
• Testing ←→Bullet Proof Jacket

Testing Pyramid

• Unit Testing: Testing a unit of your program, like testing a function, a method, a class
• Widget Testing: To make sure this widgets are error free.
• Integration Testing: Covers a large part of your application, testing a flow (ie: login flow)

Testing Structure AAA

we follow this structure no matter if we are writing a Unit Test, a Widget Test or a Integration Test

• Arrange: Provide the input for the function or method we want to test
• Act: Perform, call the function or method we want to test
• Assert: We use the expect method. Check if the result received is the same as the spected value.

TDD: Test Driven Development Life Cycle

• In TDD we write our test before writing any functionality
• Functionality Driven Development: We have a requirement and we start working towards that requirement. We write our code driven to that functionality.
• in TDD we write the failing test for the functionality first, then we make the test pass by writing the functionality. Finally we refactor our code.

Unit Testing

• We need to test a unit of our code (a functionality, afunction, a class, enum, etc)
• There are certain rules to make sure we are writing good unit tests:
  • Tests should be independent of each other.
  • There should not be any implementation logic in unit test. Because that’s what we are testing.
  • Test should be simple, fast, clean and readable. It should not depend on any network call or any other task on some other thread (create mocks for that scenario)

How to write a unit test?

void main() {
	test('Write complete description of the test', () {
		// Arrange

		// Act

		// Assert

	});
}

• Filename must end with _test
• To make a function testable you have to inject all its dependencies (never hardcode any dependency inside the function)
• The function becomes reusable and we can test it

Widget Testing

In Flutter everything is a widget, so let’s write test for widgets as well!

• Test should be independent
• There should not be creating any new widget
• Test should be simple, fast, clean & readable

Integration Testing

• Tests the complete flow of your app
• Unit tests tests a single unit and widget tests tests a single widget in your app
• To test how those units work together, you should white integration tests
• Mockito: flutter pub run build_runner build