# Go test coverage

> Set up Supercov with your agent, or run it yourself with go test.

Web page: https://supercov.com/docs/go
All Supercov pages for agents: https://supercov.com/llms.txt · Full text: https://supercov.com/llms-full.txt

Ask your coding agent to set up Supercov in your project:

```text supercov-prompt
Run Supercov with go run
github.com/supercorp-ai/supercov/cmd/supercov@latest. Read supercov docs and
check the supported Go toolchain before running our existing go test suite.
Show the coverage report and any measurement limits. Don't change
application code or tests.
```

## Run it yourself

Go support requires Go 1.22 or newer. A Go project needs Go and nothing else:
`go run` with a version suffix resolves Supercov by module path, so it neither
needs nor touches the `go.mod` in your current directory.

```sh
go run github.com/supercorp-ai/supercov/cmd/supercov@latest --version
```

You don't need Node.js. If you would rather install the binary once, Homebrew
and the platform archives on the [latest release](https://github.com/supercorp-ai/supercov/releases/latest)
carry the same build at the same version.

### Run your tests

From your module root:

```sh
go run github.com/supercorp-ai/supercov/cmd/supercov@latest -- go test ./...
```

Keep the flags your suite normally uses. Your package selection, `-run`
filters and test flags still apply.

Inspect the run:

```sh
go run github.com/supercorp-ai/supercov/cmd/supercov@latest runs latest
go run github.com/supercorp-ai/supercov/cmd/supercov@latest runs latest gaps --limit 5
```

## Check what the tests assert

Line coverage tells you a statement ran. It does not tell you that a test
checked the result. Supercov can ask [Jev](https://typesafe.ai) whether each test would fail if a
statement it ran changed. `runs latest assertions assess` saves the answers
(it needs `TYPESAFE_API_KEY`), and `runs latest assertions` then lists the
statements no test checks, file by file. A statement that is not asserted
runs in some test, but nothing that test checks depends on it. See
[Assertion coverage](https://supercov.com/docs/assertions?language=go).

## Go-specific limits

Supercov measures the packages `go test` builds, not every `.go` file in the
directory tree. Generated files and build-tagged code are measured only when the
build includes them. See [runner support](https://supercov.com/docs/supported-suites?language=go#go)
for the detail available from `go test` and its measurement limits.

Already using `go test -cover`? See [how the reports differ](https://supercov.com/compare/go-test-coverage.md).
`go run github.com/supercorp-ai/supercov/cmd/supercov@latest docs coverage-model` prints the guide for the version it runs.