binance: parse error responses (#3090)

* parse binance error responses

* fix pointer

client/mm/libxc/binance.go

@@ -1064,12 +1064,7 @@ func (bnc *binance) CancelTrade(ctx context.Context, baseID, quoteID uint32, tra
 	v.Add("symbol", slug)
 	v.Add("origClientOrderId", tradeID)
 
-	req, err := bnc.generateRequest(ctx, "DELETE", "/api/v3/order", v, nil, true, true)
-	if err != nil {
-		return err
-	}
-
-	return requestInto(req, &struct{}{})
+	return bnc.request(ctx, "DELETE", "/api/v3/order", v, nil, true, true, nil)
 }
 
 func (bnc *binance) Balances(ctx context.Context) (map[uint32]*ExchangeBalance, error) {
@@ -1195,22 +1190,14 @@ func (bnc *binance) MatchedMarkets(ctx context.Context) (_ []*MarketMatch, err e
 }
 
 func (bnc *binance) getAPI(ctx context.Context, endpoint string, query url.Values, key, sign bool, thing interface{}) error {
-	req, err := bnc.generateRequest(ctx, http.MethodGet, endpoint, query, nil, key, sign)
-	if err != nil {
-		return fmt.Errorf("generateRequest error: %w", err)
-	}
-	return requestInto(req, thing)
+	return bnc.request(ctx, http.MethodGet, endpoint, query, nil, key, sign, thing)
 }
 
 func (bnc *binance) postAPI(ctx context.Context, endpoint string, query, form url.Values, key, sign bool, thing interface{}) error {
-	req, err := bnc.generateRequest(ctx, http.MethodPost, endpoint, query, form, key, sign)
-	if err != nil {
-		return fmt.Errorf("generateRequest error: %w", err)
-	}
-	return requestInto(req, thing)
+	return bnc.request(ctx, http.MethodPost, endpoint, query, form, key, sign, thing)
 }
 
-func (bnc *binance) generateRequest(ctx context.Context, method, endpoint string, query, form url.Values, key, sign bool) (*http.Request, error) {
+func (bnc *binance) request(ctx context.Context, method, endpoint string, query, form url.Values, key, sign bool, thing interface{}) error {
 	var fullURL string
 	if strings.Contains(endpoint, "sapi") {
 		fullURL = bnc.accountsURL + endpoint
@@ -1240,7 +1227,7 @@ func (bnc *binance) generateRequest(ctx context.Context, method, endpoint string
 		raw := queryString + bodyString
 		mac := hmac.New(sha256.New, []byte(bnc.secretKey))
 		if _, err := mac.Write([]byte(raw)); err != nil {
-			return nil, fmt.Errorf("hmax Write error: %w", err)
+			return fmt.Errorf("hmax Write error: %w", err)
 		}
 		v := url.Values{}
 		v.Set("signature", hex.EncodeToString(mac.Sum(nil)))
@@ -1256,12 +1243,21 @@ func (bnc *binance) generateRequest(ctx context.Context, method, endpoint string
 
 	req, err := http.NewRequestWithContext(ctx, method, fullURL, body)
 	if err != nil {
-		return nil, fmt.Errorf("NewRequestWithContext error: %w", err)
+		return fmt.Errorf("NewRequestWithContext error: %w", err)
 	}
 
 	req.Header = header
 
-	return req, nil
+	// bnc.log.Tracef("Sending request: %+v", req)
+	var errPayload struct {
+		Code int    `json:"code"`
+		Msg  string `json:"msg"`
+	}
+	if err := dexnet.Do(req, thing, dexnet.WithSizeLimit(1<<24), dexnet.WithErrorParsing(&errPayload)); err != nil {
+		bnc.log.Errorf("request error from endpoint %q with query = %q, body = %q", endpoint, queryString, bodyString)
+		return fmt.Errorf("%w, bn code = %d, msg = %q", err, errPayload.Code, errPayload.Msg)
+	}
+	return nil
 }
 
 func (bnc *binance) handleOutboundAccountPosition(update *bntypes.StreamUpdate) {
@@ -1487,13 +1483,7 @@ func (bnc *binance) getUserDataStream(ctx context.Context) (err error) {
 			q := make(url.Values)
 			q.Add("listenKey", bnc.listenKey.Load().(string))
 			// Doing a PUT on a listenKey will extend its validity for 60 minutes.
-			req, err := bnc.generateRequest(ctx, http.MethodPut, "/api/v3/userDataStream", q, nil, true, false)
-			if err != nil {
-				bnc.log.Errorf("Error generating keep-alive request: %v. Trying again in 10 seconds.", err)
-				retryKeepAlive = time.After(time.Second * 10)
-				return
-			}
-			if err := requestInto(req, nil); err != nil {
+			if err := bnc.request(ctx, http.MethodPut, "/api/v3/userDataStream", q, nil, true, false, nil); err != nil {
 				bnc.log.Errorf("Error sending keep-alive request: %v. Trying again in 10 seconds", err)
 				retryKeepAlive = time.After(time.Second * 10)
 				return
@@ -2139,8 +2129,3 @@ func binanceMarketToDexMarkets(binanceBaseSymbol, binanceQuoteSymbol string, tok
 
 	return markets
 }
-
-func requestInto(req *http.Request, thing interface{}) error {
-	// bnc.log.Tracef("Sending request: %+v", req)
-	return dexnet.Do(req, thing, dexnet.WithSizeLimit(1<<24))
-}

dex/dexnet/http.go

@@ -19,6 +19,7 @@ type RequestOption struct {
 	responseSizeLimit int64
 	statusFunc        func(int)
 	header            *[2]string
+	errThing          interface{}
 }
 
 // WithSizeLimit sets a size limit for a response. See defaultResponseSizeLimit
@@ -39,6 +40,11 @@ func WithRequestHeader(k, v string) *RequestOption {
 	return &RequestOption{header: &h}
 }
 
+// WithErrorParsing adds parsing of response bodies for HTTP error responses.
+func WithErrorParsing(thing interface{}) *RequestOption {
+	return &RequestOption{errThing: thing}
+}
+
 // Post peforms an HTTP POST request. If thing is non-nil, the response will
 // be JSON-unmarshaled into thing.
 func Post(ctx context.Context, uri string, thing interface{}, body []byte, opts ...*RequestOption) error {
@@ -67,6 +73,7 @@ func Get(ctx context.Context, uri string, thing interface{}, opts ...*RequestOpt
 func Do(req *http.Request, thing interface{}, opts ...*RequestOption) error {
 	var sizeLimit int64 = defaultResponseSizeLimit
 	var statusFunc func(int)
+	var errThing interface{}
 	for _, opt := range opts {
 		switch {
 		case opt.responseSizeLimit > 0:
@@ -77,6 +84,8 @@ func Do(req *http.Request, thing interface{}, opts ...*RequestOption) error {
 			h := *opt.header
 			k, v := h[0], h[1]
 			req.Header.Add(k, v)
+		case opt.errThing != nil:
+			errThing = opt.errThing
 		}
 	}
 	resp, err := http.DefaultClient.Do(req)
@@ -88,6 +97,12 @@ func Do(req *http.Request, thing interface{}, opts ...*RequestOption) error {
 		statusFunc(resp.StatusCode)
 	}
 	if resp.StatusCode != http.StatusOK {
+		if errThing != nil {
+			reader := io.LimitReader(resp.Body, sizeLimit)
+			if err = json.NewDecoder(reader).Decode(errThing); err != nil {
+				return fmt.Errorf("HTTP error: %q (code %d). error encountered parsing error body: %w", resp.Status, resp.StatusCode, err)
+			}
+		}
 		return fmt.Errorf("HTTP error: %q (code %d)", resp.Status, resp.StatusCode)
 	}
 	if thing == nil {

dex/dexnet/http_live_test.go

@@ -0,0 +1,32 @@
+//go:build live
+
+package dexnet
+
+import (
+	"context"
+	"net/http"
+	"testing"
+)
+
+func TestGet(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	uri := "https://dcrdata.decred.org/api/block/best"
+	var resp struct {
+		Height int64 `json:"height"`
+	}
+	var code int
+	if err := Get(ctx, uri, &resp, WithStatusFunc(func(c int) { code = c })); err != nil {
+		t.Fatalf("Get error: %v", err)
+	}
+	if resp.Height == 0 {
+		t.Fatal("Height not parsed")
+	}
+	if code != http.StatusOK {
+		t.Fatalf("expected code 200, got %d", code)
+	}
+	// Check size limit
+	if err := Get(ctx, uri, &resp, WithSizeLimit(1)); err == nil {
+		t.Fatal("Didn't get parse error for low size limit")
+	}
+}

dex/dexnet/http_test.go

@@ -1,33 +1,29 @@
-//go:build live
-
 package dexnet
 
 import (
 	"context"
 	"net/http"
+	"net/http/httptest"
 	"testing"
 )
 
-func TestGet(t *testing.T) {
+func TestErrorParsing(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	uri := "https://dcrdata.decred.org/api/block/best"
-	var resp struct {
-		Height int64 `json:"height"`
-	}
-	var code int
-	if err := Get(ctx, uri, &resp, WithStatusFunc(func(c int) { code = c })); err != nil {
-		t.Fatalf("Get error: %v", err)
-	}
-	if resp.Height == 0 {
-		t.Fatal("Height not parsed")
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, `{"code": -150, "msg": "you messed up, bruh"}`, http.StatusBadRequest)
+	}))
+	defer ts.Close()
+
+	var errPayload struct {
+		Code int    `json:"code"`
+		Msg  string `json:"msg"`
 	}
-	if code != http.StatusOK {
-		t.Fatalf("expected code 200, got %d", code)
+	if err := Get(ctx, ts.URL, nil, WithErrorParsing(&errPayload)); err == nil {
+		t.Fatal("didn't get an http error")
 	}
-	// Check size limit
-	if err := Get(ctx, uri, &resp, WithSizeLimit(1)); err == nil {
-		t.Fatal("Didn't get parse error for low size limit")
+	if errPayload.Code != -150 || errPayload.Msg != "you messed up, bruh" {
+		t.Fatal("unexpected error body")
 	}
-
 }