From 0f70cfd8b68db0d17c34df080096a154c56e15ba Mon Sep 17 00:00:00 2001
From: Gareth Kirwan <gbjkirwan@gmail.com>
Date: Wed, 22 Oct 2025 14:25:13 +0700
Subject: [PATCH] HitBTC: Fix panic in FetchTradablePairs (#2091)
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```
❯ go test ./engine/... -run TestGetDefaultConfig
--- FAIL: TestGetDefaultConfigurations (2.01s)
    --- FAIL: TestGetDefaultConfigurations/hitbtc (0.39s)
panic: runtime error: slice bounds out of range [:-1] [recovered, repanicked]
```

The code was using strings.Index to find the quote currency position in the
symbol ID, then slicing the ID. When Index returns -1 (not found), it caused
a panic with 'slice bounds out of range [:-1]'.

Fixed by using the BaseCurrency and QuoteCurrency fields directly from the
Symbol struct, which is the correct approach and what the API provides.
---
 exchanges/hitbtc/hitbtc.go         |  4 ++--
 exchanges/hitbtc/hitbtc_test.go    | 11 ++++++++---
 exchanges/hitbtc/hitbtc_wrapper.go | 15 ++++++++-------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/exchanges/hitbtc/hitbtc.go b/exchanges/hitbtc/hitbtc.go
index bc1cc690..a382ddb1 100644
--- a/exchanges/hitbtc/hitbtc.go
+++ b/exchanges/hitbtc/hitbtc.go
@@ -103,8 +103,8 @@ func (e *Exchange) GetSymbols(ctx context.Context, symbol string) ([]string, err
 
 // GetSymbolsDetailed is the same as above but returns an array of symbols with
 // all their details.
-func (e *Exchange) GetSymbolsDetailed(ctx context.Context) ([]Symbol, error) {
-	var resp []Symbol
+func (e *Exchange) GetSymbolsDetailed(ctx context.Context) ([]*Symbol, error) {
+	var resp []*Symbol
 	return resp, e.SendHTTPRequest(ctx, exchange.RestSpot, apiV2Symbol, &resp)
 }
 
diff --git a/exchanges/hitbtc/hitbtc_test.go b/exchanges/hitbtc/hitbtc_test.go
index 61485a0f..7f96c0b4 100644
--- a/exchanges/hitbtc/hitbtc_test.go
+++ b/exchanges/hitbtc/hitbtc_test.go
@@ -992,9 +992,14 @@ func TestGetOrderInfo(t *testing.T) {
 
 func TestFetchTradablePairs(t *testing.T) {
 	t.Parallel()
-	if _, err := e.FetchTradablePairs(t.Context(), asset.Spot); err != nil {
-		t.Fatal(err)
-	}
+
+	_, err := e.FetchTradablePairs(t.Context(), asset.Futures)
+	assert.ErrorIs(t, err, asset.ErrNotSupported)
+
+	r, err := e.FetchTradablePairs(t.Context(), asset.Spot)
+	require.NoError(t, err)
+	require.NotEmpty(t, r)
+	assert.Contains(t, r, spotPair, "BTC-USD should be in the fetched pairs")
 }
 
 func TestGetCurrencyTradeURL(t *testing.T) {
diff --git a/exchanges/hitbtc/hitbtc_wrapper.go b/exchanges/hitbtc/hitbtc_wrapper.go
index 35d0c5ad..11405f2c 100644
--- a/exchanges/hitbtc/hitbtc_wrapper.go
+++ b/exchanges/hitbtc/hitbtc_wrapper.go
@@ -177,21 +177,22 @@ func (e *Exchange) Setup(exch *config.Exchange) error {
 }
 
 // FetchTradablePairs returns a list of the exchanges tradable pairs
-func (e *Exchange) FetchTradablePairs(ctx context.Context, _ asset.Item) (currency.Pairs, error) {
+func (e *Exchange) FetchTradablePairs(ctx context.Context, a asset.Item) (currency.Pairs, error) {
+	if a != asset.Spot {
+		return nil, fmt.Errorf("%w: %q", asset.ErrNotSupported, a)
+	}
+
 	symbols, err := e.GetSymbolsDetailed(ctx)
 	if err != nil {
 		return nil, err
 	}
 
 	pairs := make([]currency.Pair, len(symbols))
-	for x := range symbols {
-		index := strings.Index(symbols[x].ID, symbols[x].QuoteCurrency)
-		var pair currency.Pair
-		pair, err = currency.NewPairFromStrings(symbols[x].ID[:index], symbols[x].ID[index:])
-		if err != nil {
+	for i, s := range symbols {
+		// s.QuoteCurrency is actually settlement currency, so trim the base currency to get the real quote currency
+		if pairs[i], err = currency.NewPairFromStrings(s.BaseCurrency, strings.TrimPrefix(s.ID, s.BaseCurrency)); err != nil {
 			return nil, err
 		}
-		pairs[x] = pair
 	}
 	return pairs, nil
 }