fix(rfq-relayer): respond with failure if quote amount is zero [SLT-4…

…59] (#3391)

* Feat: return success=false if dest amount is zero

* Feat: add getQuoteResponse helper

* Feat: add test for the no quotes case

* Cleanup: explicit checks for quote type

* Cleanup: comparisons

services/rfq/api/rest/rfq_test.go

@@ -307,6 +307,15 @@ func (c *ServerSuite) TestActiveRFQFallbackToPassive() {
 	c.Assert().Equal("passive", userQuoteResp.QuoteType)
 	c.Assert().Equal("998000", userQuoteResp.DestAmount) // destAmount is quote destAmount minus fixed fee
 	c.Assert().Equal(c.relayerWallets[0].Address().Hex(), userQuoteResp.RelayerAddress)
+
+	// Submit the user quote request with a large origin amount, expect no quotes will be found
+	userQuoteReq.Data.OriginAmountExact = big.NewInt(1e18).String()
+	userQuoteResp, err = userClient.PutRFQRequest(c.GetTestContext(), userQuoteReq)
+	c.Require().NoError(err)
+
+	// Assert the response
+	c.Assert().False(userQuoteResp.Success)
+	c.Assert().Equal("no quotes found", userQuoteResp.Reason)
 }
 
 func (c *ServerSuite) TestActiveRFQPassiveBestQuote() {

services/rfq/api/rest/server.go

@@ -4,6 +4,7 @@ package rest
 import (
 	"context"
 	"encoding/json"
+	"math/big"
 
 	"fmt"
 	"net/http"
@@ -547,20 +548,35 @@ func (r *QuoterAPIServer) PutRFQRequest(c *gin.Context) {
 		span.SetAttributes(attribute.String("passive_quote_dest_amount", *passiveQuote.DestAmount))
 	}
 	quote := getBestQuote(activeQuote, passiveQuote)
+	var quoteType string
+	if quote == activeQuote {
+		quoteType = quoteTypeActive
+	} else if quote == passiveQuote {
+		quoteType = quoteTypePassive
+	}
+
+	// build and return the response
+	resp := getQuoteResponse(ctx, quote, quoteType)
+	c.JSON(http.StatusOK, resp)
+}
+
+func getQuoteResponse(ctx context.Context, quote *model.QuoteData, quoteType string) (resp model.PutRFQResponse) {
+	span := trace.SpanFromContext(ctx)
 
-	// construct the response
-	var resp model.PutRFQResponse
-	if quote == nil {
+	destAmount := big.NewInt(0)
+	if quote != nil && quote.DestAmount != nil {
+		amt, ok := destAmount.SetString(*quote.DestAmount, 10)
+		if ok {
+			destAmount = amt
+		}
+	}
+	if destAmount.Sign() <= 0 {
 		span.AddEvent("no quotes found")
 		resp = model.PutRFQResponse{
 			Success: false,
 			Reason:  "no quotes found",
 		}
 	} else {
-		quoteType := quoteTypeActive
-		if activeQuote == nil {
-			quoteType = quoteTypePassive
-		}
 		span.SetAttributes(
 			attribute.String("quote_type", quoteType),
 			attribute.String("quote_dest_amount", *quote.DestAmount),
@@ -573,7 +589,8 @@ func (r *QuoterAPIServer) PutRFQRequest(c *gin.Context) {
 			RelayerAddress: *quote.RelayerAddress,
 		}
 	}
-	c.JSON(http.StatusOK, resp)
+
+	return resp
 }
 
 func (r *QuoterAPIServer) recordLatestQuoteAge(ctx context.Context, observer metric.Observer) (err error) {