Saving pointers work

learn_go_with_tests/arrays/sum_test.go

@@ -86,6 +86,7 @@ func TestSumAll(t *testing.T) {
 func TestSumAllTails(t *testing.T) {
 
 	// Another example of helper function
+	// By defining this function inside the test, it cannot be used by other functions in this package.
 	checkSums := func(t testing.TB, got, want []int) {
 		t.Helper()
 		if !reflect.DeepEqual(got, want) {

learn_go_with_tests/pointers_errors/README.md

@@ -0,0 +1,4 @@
+# Pointers and Errors
+
+https://quii.gitbook.io/learn-go-with-tests/go-fundamentals/pointers-and-errors
+

learn_go_with_tests/pointers_errors/go.mod

@@ -0,0 +1,3 @@
+module pointers_errors
+
+go 1.21.0

learn_go_with_tests/pointers_errors/wallet.go

@@ -0,0 +1,12 @@
+package pointers_errors
+
+type Wallet struct {
+	balance int
+}
+
+func (w Wallet) Deposit(amount int) {
+}
+
+func (w Wallet) Balance() int {
+	return 0
+}

learn_go_with_tests/pointers_errors/wallet_test.go

@@ -0,0 +1,17 @@
+package pointers_errors
+
+import "testing"
+
+func TestWallet(t *testing.T) {
+
+	wallet := Wallet{}
+
+	wallet.Deposit(10)
+
+	got := wallet.Balance()
+	want := 10
+
+	if got != want {
+		t.Errorf("got %d want %d", got, want)
+	}
+}