From 625020c6e820ade39859c8d842e9cc80bf8e9372 Mon Sep 17 00:00:00 2001
From: E Sequeira <earncef@earncef.com>
Date: Thu, 29 Sep 2022 01:01:18 +0100
Subject: [PATCH] ftx: fix null currency.Pair UnmarshalJSON (#1049)

* fix ftx unmarshal

* add tests

* fix ineffectual assignment to err

* Update currency/pair_test.go

Co-authored-by: Adrian Gallagher <adrian.gallagher@thrasher.io>

Co-authored-by: Adrian Gallagher <adrian.gallagher@thrasher.io>
---
 currency/pair_methods.go |  5 +++++
 currency/pair_test.go    | 16 ++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/currency/pair_methods.go b/currency/pair_methods.go
index 841c219f..6ec9a5ea 100644
--- a/currency/pair_methods.go
+++ b/currency/pair_methods.go
@@ -34,6 +34,11 @@ func (p *Pair) UnmarshalJSON(d []byte) error {
 		return err
 	}
 
+	if pair == "" {
+		*p = EMPTYPAIR
+		return nil
+	}
+
 	newPair, err := NewPairFromString(pair)
 	if err != nil {
 		return err
diff --git a/currency/pair_test.go b/currency/pair_test.go
index afa40bfe..001df884 100644
--- a/currency/pair_test.go
+++ b/currency/pair_test.go
@@ -70,6 +70,22 @@ func TestPairUnmarshalJSON(t *testing.T) {
 		t.Errorf("Pairs UnmarshalJSON() error expected %s but received %s",
 			configPair, unmarshalHere)
 	}
+
+	encoded, err = json.Marshal(EMPTYPAIR)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = json.Unmarshal(encoded, &unmarshalHere)
+	if err != nil {
+		t.Fatal("Pair UnmarshalJSON() error", err)
+	}
+	err = json.Unmarshal([]byte("null"), &unmarshalHere)
+	if err != nil {
+		t.Fatal("Pair UnmarshalJSON() error", err)
+	}
+	if unmarshalHere != EMPTYPAIR {
+		t.Fatalf("Expected EMPTYPAIR got: %s", unmarshalHere)
+	}
 }
 
 func TestPairMarshalJSON(t *testing.T) {