orderbook: Add methods for extracting associated details from depth (#1783)

* orderbook: return identification details from depth

* Add methods, drop error as you cannot deploy without it anyway, add tests

* Update exchanges/orderbook/depth_test.go

Co-authored-by: Scott <gloriousCode@users.noreply.github.com>

* linter: fix

* gk: nits

---------

Co-authored-by: Ryan O'Hara-Reid <ryan.oharareid@thrasher.io>
Co-authored-by: Scott <gloriousCode@users.noreply.github.com>

exchanges/orderbook/depth.go

@@ -8,9 +8,11 @@ import (
 
 	"github.com/gofrs/uuid"
 	"github.com/thrasher-corp/gocryptotrader/common"
+	"github.com/thrasher-corp/gocryptotrader/common/key"
 	"github.com/thrasher-corp/gocryptotrader/currency"
 	"github.com/thrasher-corp/gocryptotrader/dispatch"
 	"github.com/thrasher-corp/gocryptotrader/exchanges/alert"
+	"github.com/thrasher-corp/gocryptotrader/exchanges/asset"
 	"github.com/thrasher-corp/gocryptotrader/log"
 )
 
@@ -785,12 +787,30 @@ func (d *Depth) GetTranches(count int) (ask, bid []Tranche, err error) {
 	return d.askTranches.retrieve(count), d.bidTranches.retrieve(count), nil
 }
 
-// GetPair returns the pair associated with the depth
-func (d *Depth) GetPair() (currency.Pair, error) {
+// Pair returns the pair associated with the depth
+func (d *Depth) Pair() currency.Pair {
 	d.m.RLock()
 	defer d.m.RUnlock()
-	if d.pair.IsEmpty() {
-		return currency.Pair{}, currency.ErrCurrencyPairEmpty
-	}
-	return d.pair, nil
+	return d.pair
+}
+
+// Asset returns the asset associated with the depth
+func (d *Depth) Asset() asset.Item {
+	d.m.RLock()
+	defer d.m.RUnlock()
+	return d.asset
+}
+
+// Exchange returns the exchange associated with the depth
+func (d *Depth) Exchange() string {
+	d.m.RLock()
+	defer d.m.RUnlock()
+	return d.exchange
+}
+
+// Key returns a combined key for the depth
+func (d *Depth) Key() key.ExchangePairAsset {
+	d.m.RLock()
+	defer d.m.RUnlock()
+	return key.ExchangePairAsset{Exchange: d.exchange, Base: d.pair.Base.Item, Quote: d.pair.Quote.Item, Asset: d.asset}
 }

exchanges/orderbook/depth_test.go

@@ -10,6 +10,8 @@ import (
 
 	"github.com/gofrs/uuid"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/thrasher-corp/gocryptotrader/common/key"
 	"github.com/thrasher-corp/gocryptotrader/currency"
 	"github.com/thrasher-corp/gocryptotrader/exchanges/asset"
 )
@@ -690,22 +692,6 @@ func TestGetTranches(t *testing.T) {
 	assert.Len(t, bidT, 5, "bids should have correct number of tranches")
 }
 
-func TestGetPair(t *testing.T) {
-	t.Parallel()
-	depth := NewDepth(id)
-
-	_, err := depth.GetPair()
-	assert.ErrorIs(t, err, currency.ErrCurrencyPairEmpty, "GetPair should error correctly")
-
-	expected := currency.NewPair(currency.BTC, currency.WABI)
-	depth.pair = expected
-
-	pair, err := depth.GetPair()
-	assert.NoError(t, err, "GetPair should not error")
-
-	assert.Equal(t, expected, pair, "GetPair should return correct pair")
-}
-
 func getInvalidDepth() *Depth {
 	depth := NewDepth(id)
 	_ = depth.Invalidate(errors.New("invalid reasoning"))
@@ -923,3 +909,39 @@ var movementTests = []struct {
 			{[]any{20.0, true}, Movement{NominalPercentage: 0.7105459985041137, ImpactPercentage: FullLiquidityExhaustedPercentage, SlippageCost: 190.0, FullBookSideConsumed: true}},
 		}},
 }
+
+func TestPair(t *testing.T) {
+	t.Parallel()
+	depth := NewDepth(id)
+	require.Empty(t, depth.Pair())
+	depth.pair = currency.NewPair(currency.BTC, currency.WABI)
+	require.Equal(t, depth.pair, depth.Pair())
+}
+
+func TestAsset(t *testing.T) {
+	t.Parallel()
+	depth := NewDepth(id)
+	require.Empty(t, depth.Asset())
+	depth.asset = asset.Spot
+	require.Equal(t, depth.asset, depth.Asset())
+}
+
+func TestExchange(t *testing.T) {
+	t.Parallel()
+	depth := NewDepth(id)
+	require.Empty(t, depth.Exchange())
+	depth.exchange = "test"
+	require.Equal(t, depth.exchange, depth.Exchange())
+}
+
+func TestKey(t *testing.T) {
+	t.Parallel()
+	depth := NewDepth(id)
+	require.Empty(t, depth.Key())
+	depth.exchange = "test"
+	depth.pair = currency.NewPair(currency.BTC, currency.WABI)
+	depth.asset = asset.Spot
+	require.Equal(t,
+		key.ExchangePairAsset{Exchange: depth.exchange, Base: depth.pair.Base.Item, Quote: depth.pair.Quote.Item, Asset: depth.asset},
+		depth.Key())
+}