---
title: Coverage reports
description: The four report formats poly-crap reads and the command that produces one for each stack.
---

Poly-crap reads the report your test runner writes; it never runs tests
itself. It reads four formats and detects each from its contents:

- LCOV, from `cargo llvm-cov`, c8, Istanbul, coverage.py, and most others.
- Cobertura XML, from `coverage xml`, pytest-cov, Jest's `cobertura` reporter,
  and .NET coverlet.
- JaCoCo XML, from the Maven and Gradle plug-ins.
- Go cover profiles, from `go test -coverprofile`.

LCOV, Cobertura, and JaCoCo give line coverage. Go profiles give statement
coverage, weighted by statement count. [JSON output](/output/machine-formats)
records which basis each function used.

## Producing a report

**Rust**

```sh
cargo llvm-cov --lcov --output-path coverage.lcov
```

**TypeScript or JavaScript**

With c8:

```sh
npx c8 --reporter=lcov npm test
```

**Python**

Either output format works:

```sh
coverage run -m pytest
coverage lcov -o coverage.lcov
```

```sh
pytest --cov --cov-report=xml
```

**Go**

```sh
go test -coverprofile=coverage.out ./...
```

**Java**

With Maven:

```sh
mvn verify
```

With Gradle:

```sh
gradle test jacocoTestReport
```

Every one of these writes to a location poly-crap
[searches on its own](/coverage/auto-discovery).