Summary

Throw matcher error if n is not a positive safe integer:

• toHaveBeenNthCalledWith and nthCalledWith
• toHaveNthReturnedWith and nthReturnedWith

Because baseline code returns pass: false a negative assertion with invalid n cannot fail :(

Do y’all think to throw error instead of false negative (pardon pun) as:

• breaking change?
• fixed error?

For consistency with other matcher errors, display received instead of jest.fn() or mock name

matcherName.slice(1) is temporary until future pull requests which will delete period from names in calls to create matcher functions.

Test plan

• Updated and renamed 8 snapshots for positive assertions
• Added 4 snapshots for negative assertions

Example pictures baseline at left and improved at right

Examples of positive assertions:

Examples of negative assertions: