Testing in software development is a process that aims to evaluate the functionality of an application with an intent to find whether the code met the specified requirements or not as well as identifying the problems to ensure that the product has expected quality.

Automated tests

Automated tests follow the process of testing the software using an automation tool to find the defects. In this process, programmers execute the test scripts and generate the test results automatically by using automation tools.

Tests in V

In V, all test files have to be named with the following format: *_test.v and the functions should start with test_*.
// sum.v in subfolder sum
module sum
pub fn sum(a, b int) int {
return a + b
// sum_test.v
import sum
fn test_sum() {
assert sum.sum(2, 3) == 5
// assert sum.sum(2, 3) == 777 // => sum_test.v:6: FAILED assertion
To execute the test, you should run v test_sum.v.


  1. 1.
    Testing JSON structures:
import json
fn test_encode_customer(){
customer := Customer{ first_name: "Vitor", last_name: "Oliveira" }
expected := '{ "first_name": "Vitor", "last_name": "Oliveira" }'
encoded_json := json.encode(customer)
assert encoded_json == expected
  1. 1.
    Testing files:
import os
fn test_file_creation() {
file_name := './new_file.txt'
content := 'text'
os.write_file(file_name, content)
assert content.len == os.file_size(file_name)
Last modified 2yr ago