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

> function nop(): op Create a no-op test operation call. The zero-argument rell.test.nop() is effectively an alias of rell.test.nop(x: integer) where
a uniqu

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

FUNCTION

# nop

```signature
function nop(): op
```

Create a no-op test operation call.

The zero-argument `rell.test.nop()` is effectively an alias of `rell.test.nop(x: integer)` where
a unique integer argument `x` is passed each time, serving the purpose of distinguishing
transactions that are identical except for the presence of a `nop` call.

#### Example:

##### Illegal

Rell

```
rell.test.tx().op(my_op).run();
rell.test.tx().op(my_op).run(); // Not allowed; all transactions must be unique!
```

##### Legal

Rell

```
// Ok, the transactions are distinct since each nop automatically uses a different nonce.
rell.test.tx().op(my_op).op(rell.test.nop()).run();
rell.test.tx().op(my_op).op(rell.test.nop()).run();
```

**See Also**

1. [NOP - Wikipedia](https://en.wikipedia.org/wiki/NOP_(code))
2. [Cryptographic nonce - Wikipedia](https://en.wikipedia.org/wiki/Cryptographic_nonce)

Since 0.10.4

---

```signature
function nop(x: integer): op
```

Create a no-op test operation call.

Serves the purpose of distinguishing transactions that are identical except for the presence of
a `nop` call.

`rell.test.nop(x)` is equivalent to `rell.test.op('nop', x.to_gtv())`, which is a test operation
call to the predefined operation:

Rell

```
operation nop(v: gtv) {}
```

#### Example:

##### Illegal

Rell

```
rell.test.tx().op(my_op).op(rell.test.nop(0)).run();
rell.test.tx().op(my_op).op(rell.test.nop(0)).run(); // Not allowed; all transactions must be unique!
```

##### Legal

Rell

```
rell.test.tx().op(my_op).op(rell.test.nop(0)).run();
rell.test.tx().op(my_op).op(rell.test.nop(1)).run(); // Ok, since the transactions are distinct.
```

**Parameters**

* **x** — the nonce

**See Also**

1. [NOP - Wikipedia](https://en.wikipedia.org/wiki/NOP_(code))
2. [Cryptographic nonce - Wikipedia](https://en.wikipedia.org/wiki/Cryptographic_nonce)

Since 0.10.4

---

```signature
function nop(x: text): op
```

Create a no-op test operation call.

Serves the purpose of distinguishing transactions that are identical except for the presence of
a `nop` call.

`rell.test.nop(x)` is equivalent to `rell.test.op('nop', x.to_gtv())`, which is a test operation
call to the predefined operation:

Rell

```
operation nop(v: gtv) {}
```

#### Example:

##### Illegal

Rell

```
rell.test.tx().op(my_op).op(rell.test.nop("a")).run();
rell.test.tx().op(my_op).op(rell.test.nop("a")).run(); // Not allowed; all transactions must be unique!
```

##### Legal

Rell

```
rell.test.tx().op(my_op).op(rell.test.nop("a")).run();
rell.test.tx().op(my_op).op(rell.test.nop("z")).run(); // Ok, since the transactions are distinct.
```

**Parameters**

* **x** — the nonce

**See Also**

1. [NOP - Wikipedia](https://en.wikipedia.org/wiki/NOP_(code))
2. [Cryptographic nonce - Wikipedia](https://en.wikipedia.org/wiki/Cryptographic_nonce)

Since 0.10.4

---

```signature
function nop(x: byte_array): op
```

Create a no-op test operation call.

Serves the purpose of distinguishing transactions that are identical except for the presence of
a `nop` call.

`rell.test.nop(x)` is equivalent to `rell.test.op('nop', x.to_gtv())`, which is a test operation
call to the predefined operation:

Rell

```
operation nop(v: gtv) {}
```

#### Example:

##### Illegal

Rell

```
rell.test.tx().op(my_op).op(rell.test.nop(x'00')).run();
rell.test.tx().op(my_op).op(rell.test.nop(x'00')).run(); // Not allowed; all transactions must be unique!
```

##### Legal

Rell

```
rell.test.tx().op(my_op).op(rell.test.nop(x'00')).run();
rell.test.tx().op(my_op).op(rell.test.nop(x'01')).run(); // Ok, since the transactions are distinct.
```

**Parameters**

* **x** — the nonce

**See Also**

1. [NOP - Wikipedia](https://en.wikipedia.org/wiki/NOP_(code))
2. [Cryptographic nonce - Wikipedia](https://en.wikipedia.org/wiki/Cryptographic_nonce)

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/nop.html)Generated API reference, mirrored from the live docs