Fixing Jasmine "encountered a declaration exception"

If you ever come upon a Jasmine unit test that ends with “encountered a declaration exception”, it’s likely because you have committed a simple, subtle mistake. Every few weeks, I would get that error, and forgetting how I fixed it the previous time, spend another 30 minutes to fix it.

Here’s the code that caused it:

describe('should be hidden when the scope is destroyed', () => {
    this.scope.$broadcast('$destroy');
    expect(this.scope.helpTooltip.hide).toHaveBeenCalledWith();
});

Can you spot the problem? It’s simple: I used describe instead of it. Let’s fix this…

it('should be hidden when the scope is destroyed', () => {
    this.scope.$broadcast('$destroy');
    expect(this.scope.helpTooltip.hide).toHaveBeenCalledWith();
});

Voilà! No more error! Sometimes, the solution is that simple.