Add unit test structure for common

go-web-app/gowiki/Makefile

@@ -2,4 +2,7 @@ build:
 	go build -o ./bin/gowiki ./cmd/gowiki/main.go
 
 clean:
-	rm -rf ./bin/gowiki
+	rm -rf ./bin/gowiki
+
+test:
+	go test ./...

go-web-app/gowiki/common/common_test.go

@@ -0,0 +1,40 @@
+package common
+
+import (
+	"log"
+	"os"
+	"testing"
+)
+
+func assertString(t *testing.T, got, want string) {
+	t.Helper()
+	if got != want {
+		log.Fatalf("Assertion failed. Got: %s want: %s", got, want)
+	}
+}
+
+func TestGetDefaultEnv(t *testing.T) {
+
+	t.Run("test key exists", func(t *testing.T) {
+		//Setup
+		want := "test value"
+		os.Setenv("TEST_KEY", want)
+		got := GetDefaultEnv("TEST_KEY", "")
+		assertString(t, got, want)
+		os.Unsetenv("TEST_KEY")
+	})
+
+	t.Run("key does not exists", func(t *testing.T) {
+		//Setup
+		want := "another test value"
+		got := GetDefaultEnv("TEST_KEY", want)
+		assertString(t, got, want)
+	})
+
+	t.Run("key maps to empty value", func(t *testing.T) {
+		//Setup
+		want := ""
+		got := GetDefaultEnv("TEST_EMPTY_KEY", want)
+		assertString(t, got, want)
+	})
+}