Hands-On RESTful API Design Patterns and Best Practices

Mutation-based fuzz tests

Mutation or dumb fuzz tests are a simple approach, wherein we create new test data by altering existing data samples. Sample data generation starts with valid samples of protocols and altering the supplied inputs, to the extent of altering every bit of the inputs. The following diagrams illustrate two ways of going about mutation:

1. Bit flipping, where inputs are flipped in a sequence or in a random manner:

2. Append a random string, where the end of the input has random strings appended: