helloworld

helloworld/go.mod

@@ -0,0 +1,3 @@
+module hello
+
+go 1.22.1

helloworld/hello.go

@@ -0,0 +1,36 @@
+package main
+
+import "fmt"
+
+const (
+  spanish = "Spanish"
+  french = "French"
+
+  englishHelloPrefix = "Hello, "
+  spanishHelloPrefix = "Hola, "
+  frenchHelloPrefix = "Bonjour, "
+)
+
+func Hello(name string, language string) string {
+  if name == "" {
+    name = "World"
+  }
+
+  return greetingPrefix(language) + name
+}
+
+func greetingPrefix(language string) (prefix string) {
+  switch language {
+  case spanish:
+    prefix = spanishHelloPrefix
+  case french:
+    prefix = frenchHelloPrefix
+  default:
+    prefix = englishHelloPrefix
+  }
+  return
+}
+
+func main() {
+  fmt.Println(Hello("world", ""))
+}

helloworld/hello_test.go

@@ -0,0 +1,33 @@
+package main
+
+import "testing"
+
+func TestHello(t *testing.T) {
+  t.Run("saying hello to people", func(t *testing.T) {
+    got := Hello("Chris", "")
+    want := "Hello, Chris"
+    assertCorrectMessage(t, got, want)
+  })
+  t.Run("say 'Hello, World' when an empty string is supplied", func(t *testing.T) {
+    got := Hello("", "")
+    want := "Hello, World"
+    assertCorrectMessage(t, got, want)
+  })
+  t.Run("in Spanish", func(t *testing.T) {
+    got := Hello("Elodie", "Spanish")
+    want := "Hola, Elodie"
+    assertCorrectMessage(t, got, want)
+  })
+  t.Run("in French", func(t *testing.T) {
+    got := Hello("Michael", "French")
+    want := "Bonjour, Michael"
+    assertCorrectMessage(t, got, want)
+  })
+}
+
+func assertCorrectMessage(t testing.TB, got, want string) {
+  t.Helper()
+  if got != want {
+    t.Errorf("got %q want %q", got, want)
+  }
+}