```sh
test_file file [test name]
```
This command can be used to run unit tests written in duckscript.<br>
It will run all test functions that start with **test_** in the given file.<br>
Each such function is considered as a test and can run any type of code and check itself using assert commands.
### Parameters
* The file name containing the test functions.
* Optional pattern for the test function to limit invocation of only those tests.
### Return Value
**true** if successful.
### Examples
This is an example of a test function:
```sh
function test_set_get_unset
unset_env TEST_SET_GET_UNSET
value = get_env TEST_SET_GET_UNSET
assert_false ${value}
value = set_env TEST_SET_GET_UNSET "test value"
assert ${value}
value = get_env TEST_SET_GET_UNSET
assert_eq ${value} "test value"
end
```