Package: universalmutator
This is a tool based on source-based rewrite of code lines for mutation generation, including
multi-language rules aided by special rules for languages or even projects.  Originally, the approach used only regular expressions,
treating code as text.  However, there is also a mode that can use theCombytool
for more sophisticated mutation that produces fewer invalid mutants.  Regular-expression based mutation works well, in our experience;
comby-aided mutation works even better.  The key advantage of either approach is that the tool can probably mutate approximatelyanyinteresting source code you have, and language changes don't force
rewriting of the mutation tool.  To use the comby mode, just make sure comby is installed and add--combywhen you runmutate.More information on this project can be found in our 2018 ICSE tool paper:https://agroce.github.io/icse18t.pdfAguest blog postfor Trail of Bits shows how to use the universalmutator to help improve a C/C++ API fuzzing effort usingDeepStateand libFuzzer.The universalmutator has support for extracting coverage information to guide mutation from theTSTLtesting tool for Python.HOW TO USE ITTo use this, you should really just do:pip install universalmutatorthenmutate --helpSIMPLE EXAMPLE USAGEmutate foo.pyormutate foo.swiftshould, if you have the appropriate compilers installed, generate a bunch of valid, non-trivially redundant, mutants.A MORE COMPLEX EXAMPLESometimes the mutated code needs to be built with a more complicated command than a simple compiler call, and of course you want help discovering which mutants are killed and not killed.  For example, to mutate and test mutants for the mandelbrot plotting example included in the PROGRAMMING RUST book (http://shop.oreilly.com/product/0636920040385.do), just do this:git clone https://github.com/ProgrammingRust/mandelbrot
cd mandelbrot
cargo build
target/debug/mandelbrot origmandel.png 1000x750 -1.20,0.35 -1,0.20
mkdir mutants
mutate src/main.rs --mutantDir mutants --noCheck
analyze_mutants src/main.rs "cargo clean; cargo build; rm mandel.png; target/debug/mandelbrot mandel.png 1000x750 -1.20,0.35 -1,0.20; diff mandel.png origmandel.png" --mutantDir mutants(It will go faster if you editmain.rsto lower the maximum number of threads used to something like 8, not 90.) At the moment, this won't use any Trivial Compiler Equivalence, but still kills about 60% of the 1000+ mutants. The killed mutant filenames will be inkilled.txtand the non-killed ones innot-killed.txt.Working with something like maven is very similar, except you can probably edit the complicated build/clean stuff to just a 'mvn test' or similar.CURRENTLY SUPPORTED LANGUAGESThe tool will likely mutate other things, if you tell it they are "c" or something, but there is auto-detection based on file ending and specific rule support for:C
C++
Java
JavaScript
Python
Swift
R
Rust
Go
Lisp
Fortran
Solidity
Vyper
Fe(the last three are smart contract languages for the Ethereum blockchain).All but C, C++, JavaScript, and Go will try, by default, to compile the mutated
file and use TCE to detect redundancy.  Of course, build dependencies
may frustrate this process, in which case --noCheck will turn off TCE
and just dump all the mutants in the directory, for pruning using a
real build process.  In the long run, we plan to integrate with
standard build systems to avoid this problem, and with automated test
generation systems such as TSTL (https://github.com/agroce/tstl) for
Python or Echidna for Solidity
(https://github.com/trailofbits/echidna).  Even now, however, withanalyze_mutantsit is fairly easy to set up automatic evaluation of
your automated test generator.MUTATING SOLIDITY CODEThe universalmutator has been most frequently applied to smart
contracts written in the Solidity language.  It supports a few special
features that are particularly useful in this context.First,
Solidity libraries are often written with onlyinternalfunctions
--- and the compiler will not emit code for such functions if you
compile a library by itself, resulting in no non-redundant mutants.
In order to handle this case,mutatecan take a--compileoption
that specifies another file (a contract using the library, or the
tests in question) that is used to check whether mutants are
redundant.Second, swapping adjacent lines of code is a seldom-used mutation
operator that is unusually attractive in a Solidity context because
swapping a state-changing operation and a requirement may reveal that
testing is incapable of detecting somere-entrancyvulnerabilities.  The testing may notice the absence of the check, but
not a mis-ordering, and these mutants may reveal that.  To add code
swaps to your mutations, just add--swapto themutatecall.  Note
that swaps work in any language; they are just particularly appealing
for smart contracts.MORE INFORMATONFor much more information, again seehttps://agroce.github.io/icse18t.pdf-- demo/tool paper at ICSE 18.The aim of this project is partly to see how quickly mutation can be applied to new languages, partly how much the work of a tool can be
offloaded to the compiler / test analysis tools.Authors:  Alex Groce, Josie Holmes, Darko Marinov, August Shi, Lingming Zhang