joshdover

Idiomatic React Testing Patterns

Testing React components seems simple at first. Then you need to test something that isn't a pure interaction and things seem to break down. These 4 patterns should help you write readable, flexible tests for the type of component you are testing.

Setup

I recommend doing all setup in the most functional way possible. If you can avoid it, don't set variables in a beforeEach. This will help ensure tests are isolated and make things a bit easier to reason about. I use a pattern that gives great defaults for each test example but allows every example to override props when needed:

benjanderson

public static class SqlExceptionCreator
{
	public static SqlException Create(string message, int errorCode)
	{
		SqlException exception = Instantiate<SqlException>();
		SetProperty(exception, "_message", message);

		var errors = new ArrayList();

		var errorCollection = Instantiate<SqlErrorCollection>();