clients/horizonclient: fix multi-parameter url for claimable balance query

clients/horizonclient/claimable_balance_request.go

@@ -13,24 +13,29 @@ import (
 func (cbr ClaimableBalanceRequest) BuildURL() (endpoint string, err error) {
 	endpoint = "claimable_balances"
 
+	//max limit is 200
+	if cbr.Limit > 200 {
+		return endpoint, errors.New("invalid request: limit " + fmt.Sprint(cbr.Limit) + " is greater than limit max of 200")
+	}
+
 	// Only one filter parameter is allowed, and you can't mix an ID query and
 	// filters.
 	nParams := countParams(cbr.Asset, cbr.Claimant, cbr.Sponsor, cbr.ID)
-	if nParams > 1 {
+	if cbr.ID != "" && nParams > 1 {
 		return endpoint, errors.New("invalid request: too many parameters")
 	}
 
 	if cbr.ID != "" {
 		endpoint = fmt.Sprintf("%s/%s", endpoint, cbr.ID)
 	} else {
+		params := map[string]string{
+			"claimant": cbr.Claimant,
+			"sponsor":  cbr.Sponsor,
+			"asset":    cbr.Asset,
+		}
 		queryParams := addQueryParams(
-			map[string]string{
-				"claimant": cbr.Claimant,
-				"sponsor":  cbr.Sponsor,
-				"asset":    cbr.Asset,
-			},
+			params, limit(cbr.Limit), cursor(cbr.Cursor),
 		)
-
 		endpoint = fmt.Sprintf("%s?%s", endpoint, queryParams)
 	}
 

clients/horizonclient/claimable_balance_request_test.go

@@ -0,0 +1,53 @@
+package horizonclient
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestClaimableBalanceBuildUrl(t *testing.T) {
+
+	cbr := ClaimableBalanceRequest{
+		ID: "1235",
+	}
+	url, err := cbr.BuildURL()
+	assert.Equal(t, "claimable_balances/1235", url)
+	assert.NoError(t, err)
+
+	//if the ID is included, you cannot include another parameter
+	cbr = ClaimableBalanceRequest{
+		ID:       "1235",
+		Claimant: "CLAIMANTADDRESS",
+	}
+	_, err = cbr.BuildURL()
+	assert.EqualError(t, err, "invalid request: too many parameters")
+
+	//if you have two parameters, and neither of them are ID, it must use both in the URL
+	cbr = ClaimableBalanceRequest{
+		Claimant: "CLAIMANTADDRESS",
+		Asset:    "TEST:ISSUERADDRESS",
+	}
+	url, err = cbr.BuildURL()
+	assert.NoError(t, err)
+	assert.Equal(t, "claimable_balances?asset=TEST%3AISSUERADDRESS&claimant=CLAIMANTADDRESS", url)
+
+	//check limit
+	cbr = ClaimableBalanceRequest{
+		Claimant: "CLAIMANTADDRESS",
+		Asset:    "TEST:ISSUERADDRESS",
+		Limit:    200,
+	}
+	url, err = cbr.BuildURL()
+	assert.NoError(t, err)
+	assert.Equal(t, "claimable_balances?asset=TEST%3AISSUERADDRESS&claimant=CLAIMANTADDRESS&limit=200", url)
+
+	cbr = ClaimableBalanceRequest{
+		Claimant: "CLAIMANTADDRESS",
+		Asset:    "TEST:ISSUERADDRESS",
+		Limit:    201,
+	}
+	_, err = cbr.BuildURL()
+	assert.EqualError(t, err, "invalid request: limit 201 is greater than limit max of 200")
+
+}

clients/horizonclient/main.go

@@ -434,6 +434,8 @@ type ClaimableBalanceRequest struct {
 	Asset    string
 	Sponsor  string
 	Claimant string
+	Cursor   string
+	Limit    uint
 }
 
 // ServerTimeRecord contains data for the current unix time of a horizon server instance, and the local time when it was recorded.