TypeError: expect(…).tobeinthedocument is not a function
This error message indicates that the function toBeInTheDocument is not defined or not a function in the specific testing framework being used, such as Jest or Jasmine.
The usual reason for this error is that you may be mistyping the function name or using the wrong syntax to call it.
To better understand this error, let’s consider an example with the Jest testing framework:
test('example test', () => {
expect(someElement).toBeInTheDocument();
});
In this example, we are testing whether the variable someElement is present in the document. The toBeInTheDocument function is an assertion provided by Jest to check for the existence of an element.
However, if toBeInTheDocument is mistyped as tobeinthedocument (lowercase letters instead of camel case), or if it is accidentally written as tobeinthedocument() (with parentheses), then the error TypeError: expect(...).tobeinthedocument is not a function will be thrown.
To fix this error, make sure you are using the correct function name (toBeInTheDocument) and ensure it is written properly without any typos. Also, make sure you are using the appropriate testing framework and have the necessary dependencies, such as Jest or Jasmine, properly installed.