# op.run · Rell standard library · Chromia Docs (concept)

> function run(): unit Build a test block containing a single test transaction, which contains only this test
operation call. Since 0.10.4

Source: https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/run/

FUNCTION

# op.run

```signature
function run(): unit
```

Build a test block containing a single test transaction, which contains only this test
operation call.

Since 0.10.4

[View this page on docs.chromia.com](https://docs.chromia.com/pages/rell-stdlib/-rell%20-system%20-library/rell.test/op/run.html)Generated API reference, mirrored from the live docs