Edge Case - Software Engineering

Software Engineering

In programming, an edge case is typically a unit test that tests a boundary condition of an algorithm, function or method. A series of edge cases around each "boundary" can be used to give reasonable coverage and confidence using the assumption that if it behaves correctly at the edges, it should behave everywhere else.

For example, a function that divides two numbers, might be tested using both very large and very small numbers, with the assumption that if it works for both ends of the magnitude spectrum, it should work correctly in between - i.e. for all magnitudes of numbers.