feat: v5 get orderbook (#102)

* feat: implement

* test: integration

* test: unit

* docs: update

README.md

@@ -124,6 +124,7 @@ The following API endpoints have been implemented
 - [`/v5/market/index-price-kline` Get Index Price Kline](https://bybit-exchange.github.io/docs/v5/market/index-kline)
 - [`/v5/market/premium-index-price-kline` Get Premium Index Price Kline](https://bybit-exchange.github.io/docs/v5/market/preimum-index-kline)
 - [`/v5/market/instruments-info` Get Instruments Info](https://bybit-exchange.github.io/docs/v5/market/instrument)
+- [`/v5/market/orderbook` Get Orderbook](https://bybit-exchange.github.io/docs/v5/market/orderbook)
 - [`/v5/market/tickers` Get Tickers](https://bybit-exchange.github.io/docs/v5/market/tickers)
 
 #### Position

integrationtest/v5/market/market_test.go

@@ -107,6 +107,20 @@ func TestGetInstrumentsInfo(t *testing.T) {
 	}
 }
 
+func TestGetOrderbook(t *testing.T) {
+	client := bybit.NewTestClient()
+	res, err := client.V5().Market().GetOrderbook(bybit.V5GetOrderbookParam{
+		Category: bybit.CategoryV5Spot,
+		Symbol:   bybit.SymbolV5BTCUSDT,
+	})
+	require.NoError(t, err)
+	{
+		goldenFilename := "./testdata/v5-market-get-orderbook.json"
+		testhelper.Compare(t, goldenFilename, testhelper.ConvertToJSON(res.Result))
+		testhelper.UpdateFile(t, goldenFilename, testhelper.ConvertToJSON(res.Result))
+	}
+}
+
 func TestGetTickers(t *testing.T) {
 	client := bybit.NewTestClient()
 	{

integrationtest/v5/market/testdata/v5-market-get-orderbook.json

@@ -0,0 +1,17 @@
+{
+  "s": "BTCUSDT",
+  "b": [
+    {
+      "price": "21638.47",
+      "quantity": "0.047237"
+    }
+  ],
+  "a": [
+    {
+      "price": "21643.13",
+      "quantity": "0.033243"
+    }
+  ],
+  "ts": 1678369185237,
+  "u": 3936309
+}

v5_market_service.go

@@ -16,6 +16,7 @@ type V5MarketServiceI interface {
 	GetIndexPriceKline(V5GetIndexPriceKlineParam) (*V5GetIndexPriceKlineResponse, error)
 	GetPremiumIndexPriceKline(V5GetPremiumIndexPriceKlineParam) (*V5GetPremiumIndexPriceKlineResponse, error)
 	GetInstrumentsInfo(V5GetInstrumentsInfoParam) (*V5GetInstrumentsInfoResponse, error)
+	GetOrderbook(V5GetOrderbookParam) (*V5GetOrderbookResponse, error)
 	GetTickers(V5GetTickersParam) (*V5GetTickersResponse, error)
 }
 
@@ -485,6 +486,78 @@ func (s *V5MarketService) GetInstrumentsInfo(param V5GetInstrumentsInfoParam) (*
 	return &res, nil
 }
 
+// V5GetOrderbookParam :
+type V5GetOrderbookParam struct {
+	Category CategoryV5 `url:"category"`
+	Symbol   SymbolV5   `url:"symbol"`
+
+	// spot: [1, 50]. Default: 1.
+	// linear&inverse: [1, 200]. Default: 25.
+	// option: [1, 25]. Default: 1.
+	Limit *int `url:"limit,omitempty"`
+}
+
+// V5GetOrderbookResponse :
+type V5GetOrderbookResponse struct {
+	CommonV5Response `json:",inline"`
+	Result           V5GetOrderbookResult `json:"result"`
+}
+
+// V5GetOrderbookResult :
+type V5GetOrderbookResult struct {
+	Symbol    SymbolV5              `json:"s"`
+	Bids      V5GetOrderbookBidAsks `json:"b"`
+	Asks      V5GetOrderbookBidAsks `json:"a"`
+	Timestamp int64                 `json:"ts"`
+	UpdateID  int                   `json:"u"`
+}
+
+// V5GetOrderbookBidAsks :
+type V5GetOrderbookBidAsks []V5GetOrderbookBidAsk
+
+// UnmarshalJSON :
+func (b *V5GetOrderbookBidAsks) UnmarshalJSON(data []byte) error {
+	parsedData := [][]string{}
+	if err := json.Unmarshal(data, &parsedData); err != nil {
+		return err
+	}
+	items := V5GetOrderbookBidAsks{}
+	for _, item := range parsedData {
+		item := item
+		if len(item) != 2 {
+			return errors.New("so far len(item) must be 2, please check it on documents")
+		}
+		items = append(items, V5GetOrderbookBidAsk{
+			Price:    item[0],
+			Quantity: item[1],
+		})
+	}
+	*b = items
+	return nil
+}
+
+// V5GetOrderbookBidAsk :
+type V5GetOrderbookBidAsk struct {
+	Price    string `json:"price"`
+	Quantity string `json:"quantity"`
+}
+
+// GetOrderbook :
+func (s *V5MarketService) GetOrderbook(param V5GetOrderbookParam) (*V5GetOrderbookResponse, error) {
+	var res V5GetOrderbookResponse
+
+	queryString, err := query.Values(param)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := s.client.getPublicly("/v5/market/orderbook", queryString, &res); err != nil {
+		return nil, err
+	}
+
+	return &res, nil
+}
+
 // V5GetTickersParam :
 type V5GetTickersParam struct {
 	Category CategoryV5 `url:"category"`

v5_market_service_test.go

@@ -370,6 +370,54 @@ func TestV5Market_GetInstrumentsInfo(t *testing.T) {
 	})
 }
 
+func TestV5Market_GetOrderbook(t *testing.T) {
+	param := V5GetOrderbookParam{
+		Category: CategoryV5Spot,
+		Symbol:   SymbolV5BTCUSDT,
+	}
+
+	path := "/v5/market/orderbook"
+	method := http.MethodGet
+	status := http.StatusOK
+	respBody := map[string]interface{}{
+		"result": map[string]interface{}{
+			"s": "BTCUSDT",
+			"a": [][]interface{}{
+				{
+					"16638.64",
+					"0.008479",
+				},
+			},
+			"b": [][]interface{}{
+				{
+					"16638.27",
+					"0.305749",
+				},
+			},
+			"ts": 1672765737733,
+			"u":  5277055,
+		},
+	}
+	bytesBody, err := json.Marshal(respBody)
+	require.NoError(t, err)
+
+	server, teardown := testhelper.NewServer(
+		testhelper.WithHandlerOption(path, method, status, bytesBody),
+	)
+	defer teardown()
+
+	client := NewTestClient().
+		WithBaseURL(server.URL)
+
+	resp, err := client.V5().Market().GetOrderbook(param)
+	require.NoError(t, err)
+
+	require.NotNil(t, resp)
+	assert.Equal(t, respBody["result"].(map[string]interface{})["s"], string(resp.Result.Symbol))
+	assert.Equal(t, respBody["result"].(map[string]interface{})["a"].([][]interface{})[0][0], string(resp.Result.Asks[0].Price))
+	assert.Equal(t, respBody["result"].(map[string]interface{})["b"].([][]interface{})[0][0], string(resp.Result.Bids[0].Price))
+}
+
 func TestV5Market_GetTickers(t *testing.T) {
 	t.Run("linear", func(t *testing.T) {
 		param := V5GetTickersParam{