Question 1

What is JMIT?

Accepted Answer

JMIT (Just Make It Work) is a Python test enforcement tool that detects weak, silent, and zero-assertion tests in pytest suites and auto-repairs them with mutation-verified replacements. It helps Python developers discover tests that always pass — even when the code they test is broken.

Question 2

What is a zero-assertion test?

Accepted Answer

A zero-assertion test is a test function with no assert statements. It will always pass regardless of what the code does, giving false confidence that the functionality works. JMIT detects these automatically by parsing test files with an AST scanner.

Question 3

How does JMIT's mutation verification work?

Accepted Answer

JMIT applies single-operator mutations to source code (operator swaps, boolean flips, return value changes), runs pytest, then unconditionally rolls back all mutations in a finally block. If the new test fails on the mutation, it is confirmed as binding. Your source code is never permanently changed.

Question 4

What is the Test Binding Score?

Accepted Answer

The Test Binding Score is JMIT's mutation resilience rating — a percentage representing how many of your tests are binding (would fail if the code they test were mutated). It is calculated by running mutation verification against flagged weak tests and reporting the fraction that provably catch bugs.

Question 5

How much does JMIT cost?

Accepted Answer

JMIT offers a 7-day free trial with full access, no credit card required. After the trial: Solo plan is €29/month (1 developer), Team plan is €99/month (up to 5 developers), and Enterprise pricing is available on request. All prices are in EUR.

Question 6

How do I install JMIT?

Accepted Answer

Install JMIT via pip: pip install jmit. Then run jmit run --root . to audit your repository. The 7-day free trial starts automatically on first use. Alternatively, JMIT is available as a Claude Code skill: type /jmit in Claude Code to run the full audit pipeline without installing anything.

Question 7

Is JMIT different from code coverage tools?

Accepted Answer

Yes. Coverage tools (like pytest-cov) measure which lines are executed by tests. They cannot detect whether tests actually verify behavior. A zero-assertion test achieves 100% line coverage while catching zero bugs. JMIT measures whether tests are binding — whether they would fail if the code were mutated.

Question 8

What Python versions does JMIT support?

Accepted Answer

JMIT requires Python 3.11 or above. It is distributed as a pure Python pip package and runs on all architectures where Python 3.11+ is available, including x86_64, aarch64 (ARM64/Apple Silicon/AWS Graviton), Windows, Linux, and macOS.