class MockPropertyContext | Node.js node:test module | Bun

A getter that returns a copy of the internal array used to track accesses (get/set) to the mocked property. Each entry in the array is an object with the following properties:

This function returns the number of times that the property was accessed. This function is more efficient than checking ctx.accesses.length because ctx.accesses is a getter that creates a copy of the internal access tracking array.

The number of times that the property was accessed (read or written).

This function is used to change the value returned by the mocked property getter.

The new value to be set as the mocked property value.

This function is used to change the behavior of an existing mock for a single invocation. Once invocation onAccess has occurred, the mock will revert to whatever behavior it would have used had mockImplementationOnce() not been called.

The following example creates a mock function using t.mock.property(), calls the mock property, changes the mock implementation to a different value for the next invocation, and then resumes its previous behavior.

test('changes a mock behavior once', (t) => {
const obj = { foo: 1 };

const prop = t.mock.property(obj, 'foo', 5);

assert.strictEqual(obj.foo, 5);
prop.mock.mockImplementationOnce(25);
assert.strictEqual(obj.foo, 25);
assert.strictEqual(obj.foo, 5);
});

The value to be used as the mock's implementation for the invocation number specified by onAccess.

The invocation number that will use value. If the specified invocation has already occurred then an exception is thrown. Default: The number of the next invocation.

Resets the access history of the mocked property.

Resets the implementation of the mock property to its original behavior. The mock can still be used after calling this function.