array
Should return 0 when both the values are null
Should return in favor of non null value if one is null
basic test
date
Should throw error if both the objects are undefined or
object
When you compare two different types of object, their types string representation are used for sorting
same object comparison
same object different value comparison
number
Should return 0 when both the values are NaN
Should return in favor of a number value if one is NaN
Should accept number in string form
Should return 1 when left hand side is greater, -1 when right hand side is greater, 0, when both are equal
Values are used to sort, when we have same keys
Keys length is used as first comparison
If a prop from first object is missing in second object, first object comes before obj2, when both object have same key length
string
default is Case sensitive comparison
diff
Should return undef when both the values are same
Should return new value when they are not same
is
Should return false if object is null
Should return true for correct object type
Should return true for instance of specific class if Object passed as Type
