Hi there! I keep learning golang. Today I wrote tests and created maps 🙂
First of all I created a function using Golang’s official documentation like below:
func Greetings(names []string) (map[string]string, error) {
messages := make(map[string]string)
for _, name := range names {
message, err := Hello(name)
if err != nil {
return nil, err
}
messages[name] = message
}
return messages, nil
}The above function expects a string map. It returns a string map and error. There is a loop in this function to iterate names.
If you pass an empty name to the Hello function, it will return an error.
func Hello(name string) (string, error) {
if name == "" {
return name, errors.New("The name can't be blank!")
}
message := fmt.Sprintf(randomFormat(), name)
return message, nil
}I also created a random function to return random hello values 🙂
// return a random string
func randomFormat() string {
formats := []string{
"Hi %v. How are you?",
"Merhaba %v. Nasılsın?",
"Hi. I'm %v. Nice to meet you",
}
return formats[rand.Intn(len(formats))]
}I created a test file for this module. Every go test file should contains _test in their names.
package greetings import ( "regexp" "testing" )
The header of this test file was like above. And I created my first test:
func TestHelloName(t *testing.T) {
name := "Ali"
want := regexp.MustCompile(<code>{{EJS0}}</code> + name + <code>{{EJS1}}</code>)
message, err := Hello(name)
if !want.MatchString(message) || err != nil {
t.Fatalf(<code>{{EJS2}}</code>, message, err, want)
}
}The above example showed me how can I write a test. For example, your test function should starts with Test prefix. It should take a *testing.T. I think this an interface. I don’t know for now.
My second test was like that:
func TestHelloEmpty(t *testing.T) {
message, err := Hello("")
if message != "" || err == nil {
t.Fatalf(<code>{{EJS3}}</code>, message, err)
}
}All test should output Fatal. There are some format params in the string. Actually, I don’t know format params clearly for now. But, I test for empty string.
If you want to run these tests, just type this commands in your command line:
go test -v === RUN TestHelloName --- PASS: TestHelloName (0.00s) === RUN TestHelloEmpty --- PASS: TestHelloEmpty (0.00s) PASS ok github.com/aligoren/go_learn/greetings 0.002s
That’s all. I imported my local file to my new module. Now, it should work as I expected.
main.go file should be like that:
package main
import (
"fmt"
"log"
"github.com/aligoren/go_learn/greetings"
)
func main() {
names := []string{"Ali", "Burak", "Can"}
messages, err := greetings.Greetings(names)
if err != nil {
log.Fatal(err)
}
fmt.Println(messages)
}I ran this command:
go run . map[Ali:Hi Ali. How are you? Burak:Hi. I'm Burak. Nice to meet you Can:Hi Can. How are you?]
That’s all 🙂
You can check my GitHub repository for these two modules.
Thanks for reading ^_^