♻️ (bitcoin-wallet): refactor test with bitcoin stringer

Author: yuanyu90221

pointers-and-errors/bitcoin-and-wallet.go

@@ -1,6 +1,14 @@
 package pointers_and_errors
 
+import "fmt"
+
 type Bitcoin int
+
+// String - stringer for Bitcoin
+func (b Bitcoin) String() string {
+	return fmt.Sprintf("%d BTC", b)
+}
+
 type Wallet struct {
 	balance Bitcoin
 }

pointers-and-errors/bitcoin-and-wallet_test.go

@@ -10,6 +10,6 @@ func TestWallet(t *testing.T) {
 	got := wallet.Balance()
 	want := Bitcoin(10)
 	if got != want {
-		t.Errorf("got %d, want %d", got, want)
+		t.Errorf("got %v, want %v", got, want)
 	}
 }