Hello world done

learn_go_with_tests/helloworld/hello.go

@@ -1,12 +1,49 @@
+// Provides a Hello world example with tests
 package main
 
-import "fmt"
+import (
+	"fmt"
+)
+
+// Constants can be grouped in a block.
+// Add a line between related consts for
+// readbility
+const (
+	french  = "French"
+	spanish = "Spanish"
+
+	englishHelloPrefix = "Hello, "
+	spanishHelloPrefix = "Hola, "
+	frenchHelloPrefix  = "Bonjour, "
+)
 
 // Hello prints the string "Hello, world"
-func Hello(name string) string {
-	return "Hello, " + name
+func Hello(name string, language string) string {
+	if name == "" {
+		name = "World"
+	}
+
+	return greetingPrefix(language) + name
+}
+
+// greetingPrefix Using a named return value will initialize a "zero value"
+// variable which as you can see below can be assigned to.
+// this will display in Go Doc for your function.
+// Lower case letter functions are "private" functions. They are internal to implementation.
+func greetingPrefix(language string) (prefix string) {
+	switch language {
+	case french:
+		prefix = frenchHelloPrefix
+	case spanish:
+		prefix = spanishHelloPrefix
+	default:
+		prefix = englishHelloPrefix
+	}
+	// we use names return value in function signature
+	return
+
 }
 
 func main() {
-	fmt.Println(Hello("world"))
+	fmt.Println(Hello("world", ""))
 }

learn_go_with_tests/helloworld/hello_test.go

@@ -3,9 +3,37 @@ package main
 import "testing"
 
 func TestHello(t *testing.T) {
-	got := Hello("Drew")
-	expected := "Hello, Drew"
+	t.Run("saying hello to people", func(t *testing.T) {
+		got := Hello("Drew", "")
+		expected := "Hello, Drew"
+		assertCorrectMessage(t, got, expected)
 
+	})
+
+	t.Run("say 'Hello, world' when an empty string is supplied", func(t *testing.T) {
+		got := Hello("", "")
+		expected := "Hello, World"
+		assertCorrectMessage(t, got, expected)
+	})
+
+	t.Run("in Spanish", func(t *testing.T) {
+		got := Hello("Elodie", "Spanish")
+		expected := "Hola, Elodie"
+		assertCorrectMessage(t, got, expected)
+	})
+
+	t.Run("in French", func(t *testing.T) {
+		got := Hello("Drew", "French")
+		expected := "Bonjour, Drew"
+		assertCorrectMessage(t, got, expected)
+	})
+}
+
+func assertCorrectMessage(t testing.TB, got, expected string) {
+	// Needed to tell the test suite that this method is a helper.
+	// By doing this when it fails the line number reported will be in
+	// our function call rather than inside our test helper.
+	t.Helper()
 	if got != expected {
 		t.Errorf("got %q, expected %q", got, expected)
 	}