```sh
assert value [error message]
```
Used to validate the input is truthy.<br>
If the value is one of the following:
* No output
* false (case insensitive)
* 0
* no (case insensitive)
* Empty value
It is considered falsy and will exist with an error.
### Parameters
* The value to evaluate
* Optional error message
### Return Value
**true** if truthy.
### Examples
```sh
# valid conditions
assert ok
assert true
assert yes
value = set "some text"
assert ${value}
# error conditions (each one will break the execution)
assert
assert false
assert 0
assert false "This is my error message"
```