Asserts that the property exists on the target object.
OptionalevalMsg: MsgSourceThe evaluation message source.
A new assertion instance this with the value of the property.
AssertionFailure if the symbol property does not exist.
AssertionFailure if the symbol property value does not match the expected value.
Represents a function that defines a symbol assertion for the default symbol. Asserts that the specified symbol property exists on the target object.