Necessist

Runs tests with statements removed to help identify unnecessary statements

Setup

cd necessist
cargo build --workspace
source env.sh

Usage

1. Checkout a clean copy of your target repository. This is important!
2. cd target-repo
3. necessist_instrument.sh
4. cargo necessist

By default, necessist outputs to the console. Passing --sqlite causes necessist to instead output to a sqlite database. A tool like sqlitebrowser can then be used to filter/sort the results.

Output

Silencing timed-out and failed results

• Passing -qqq silences timed-out and failed results for all statements except local (let) bindings.
• Passing -qqqq silences timed-out and failed results entirely.

Skipped statements

Necessist will not attempt to remove a statement if any of the following conditions apply.

• The statement is an invocation of a whitelisted macro.
• --skip-calls regex is passed and the statement is a function call, macro invocation, or method call matching regex.
• --skip-controls is passed and the statement is a break or continue.
• --skip-locals is passed and the statement is a local (let) binding.

Whitelisted macros

• assert
• assert_eq
• assert_ne
• panic
• unimplemented
• unreachable

References

• Groce, A., Ahmed, I., Jensen, C., McKenney, P.E., Holmes, J.: How verified (or tested) is my code? Falsification-driven verification and testing. Autom. Softw. Eng. 25, 917–960 (2018). A preprint is available here. See Section 2.3.