accounts/keystore: add test case for prefix bug fix

accounts/keystore/keystore_plain_test.go

@@ -253,6 +253,25 @@ func TestKeyForDirectICAP(t *testing.T) {
 	}
 }
 
+func TestNewKeyForDirectICAP(t *testing.T) {
+	addr0 := common.HexToAddress("0x00ffffffffffffffffffffffffffffffffffffff")
+	addr1 := common.HexToAddress("0xffffffffffffffffffffffffffffffffffffffff")
+	tests := []struct {
+		name   string
+		result bool
+	}{
+		{"addresses start with 0", addr0[0] == 0},
+		{"addresses not start with 0", addr1[0] != 0},
+		{"addr0 starts with 0x00 or xdc00", strings.HasPrefix(addr0.Hex(), "0x00") || strings.HasPrefix(addr0.Hex(), "xdc00")},
+		{"addr1 not start with 0x00 or xdc00", !(strings.HasPrefix(addr1.Hex(), "0x00") && strings.HasPrefix(addr1.Hex(), "xdc00"))},
+	}
+	for _, tt := range tests {
+		if !tt.result {
+			t.Errorf("test %q failed\n", tt.name)
+		}
+	}
+}
+
 func TestV3_31_Byte_Key(t *testing.T) {
 	t.Skip("This test does not ")
 	t.Parallel()