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

> type op A test operation call, consisting of a name (an operation's mount name ), and a list of arguments
(a list<gtv> ). See Also Mount names - Chromia Do

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

TYPE

# op

On this page

* [Attributes](#attributes)
* [Methods](#methods)

```signature
type op
```

A test operation call, consisting of a name (an operation's *mount name*), and a list of arguments
(a `list<gtv>`).

**See Also**

1. [Mount names - Chromia Documentation](https://docs.chromia.com/rell/language-features/modules/mount/)
2. [`list` - Rell Standard Library](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/root/list/)
3. [`gtv` - Rell Standard Library](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/root/gtv/)

Since 0.10.4

## Attributes

`name: text`
:   The name of operation called by this test operation call.

    Since 0.13.4

`args: list<gtv>`
:   The arguments passed to the operation in this test operation call.

    Since 0.13.4

## Methods

[op](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/op/)

[run](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/run/)
:   Build a test block containing a single test transaction, which contains only this test

[run\_must\_fail](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/run_must_fail/)
:   Assert that this test operation call fails.

[sign](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/sign/)
:   Create a test transaction builder containing this test operation call, and add the keypairs in

[to\_gtx\_operation](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/to_gtx_operation/)
:   Convert this test operation call to a gtxoperation.

[tx](https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/rell.test/op/tx/)
:   Create a test transaction builder containing this test operation call.

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