rpc: remove hardcoded data in test

rpc/subscription_test.go

@@ -270,11 +270,20 @@ func TestNotify(t *testing.T) {
 	msg := &types.Header{
 		ParentHash: common.HexToHash("0x01"),
 		Number:     big.NewInt(100),
+		Difficulty: common.Big0,
 	}
 	notifier.Notify(id, msg)
-	have := strings.TrimSpace(out.String())
-	want := `{"jsonrpc":"2.0","method":"_subscription","params":{"subscription":"test","result":{"parentHash":"0x0000000000000000000000000000000000000000000000000000000000000001","sha3Uncles":"0x0000000000000000000000000000000000000000000000000000000000000000","miner":"0x0000000000000000000000000000000000000000","stateRoot":"0x0000000000000000000000000000000000000000000000000000000000000000","transactionsRoot":"0x0000000000000000000000000000000000000000000000000000000000000000","receiptsRoot":"0x0000000000000000000000000000000000000000000000000000000000000000","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","difficulty":null,"number":"0x64","gasLimit":"0x0","gasUsed":"0x0","timestamp":"0x0","extraData":"0x","mixHash":"0x0000000000000000000000000000000000000000000000000000000000000000","nonce":"0x0000000000000000","baseFeePerGas":null,"withdrawalsRoot":null,"blobGasUsed":null,"excessBlobGas":null,"parentBeaconBlockRoot":null,"hash":"0xe5fb877dde471b45b9742bb4bb4b3d74a761e2fb7cb849a3d2b687eed90fb604"}}}`
-	if have != want {
+
+	type Response struct {
+		Params struct {
+			Result types.Header
+		}
+	}
+	var resp Response
+	if err := json.Unmarshal(out.Bytes(), &resp); err != nil {
+		t.Errorf("failed to unmarshal response: %v", err)
+	}
+	if have, want := resp.Params.Result.Hash(), msg.Hash(); have != want {
 		t.Errorf("have:\n%v\nwant:\n%v\n", have, want)
 	}
 }