Add option to use all funds for channel with CLNRest

backends/CLNRest.ts

@@ -280,24 +280,16 @@ export default class CLNRest {
         const feeRate = `${new BigNumber(data.sat_per_vbyte || 0)
             .times(1000)
             .toString()}perkb`;
-        if (data.utxos && data.utxos.length > 0) {
-            request = {
-                id: data.id,
-                amount: data.satoshis,
-                feerate: feeRate,
-                announce: !data.privateChannel ? true : false,
-                minconf: data.min_confs,
-                utxos: data.utxos
-            };
-        } else {
-            request = {
-                id: data.id,
-                amount: data.satoshis,
-                feerate: feeRate,
-                announce: !data.privateChannel ? true : false,
-                minconf: data.min_confs
-            };
-        }
+
+        request = {
+            id: data.id,
+            amount: data.fundMax ? 'all' : data.satoshis,
+            feerate: feeRate,
+            announce: !data.privateChannel ? true : false,
+            minconf: data.min_confs
+        };
+
+        if (data.utxos && data.utxos.length > 0) request.utxos = data.utxos;
 
         return this.postRequest('/v1/fundchannel', request);
     };
@@ -420,6 +412,7 @@ export default class CLNRest {
     supportsOnchainSendMax = () => true;
     supportsOnchainBatching = () => false;
     supportsChannelBatching = () => false;
+    supportsChannelFundMax = () => true;
     supportsLSPS1customMessage = () => false;
     supportsLSPS1rest = () => true;
     supportsBolt11BlindedRoutes = () => false;

backends/EmbeddedLND.ts

@@ -317,6 +317,7 @@ export default class EmbeddedLND extends LND {
     supportsOnchainSendMax = () => this.supports('v0.18.3');
     supportsOnchainBatching = () => true;
     supportsChannelBatching = () => true;
+    supportsChannelFundMax = () => true;
     supportsLSPS1customMessage = () => true;
     supportsLSPS1rest = () => false;
     supportsOffers = () => false;

backends/LND.ts

@@ -703,6 +703,7 @@ export default class LND {
     supportsOnchainSendMax = () => this.supports('v0.18.3');
     supportsOnchainBatching = () => true;
     supportsChannelBatching = () => true;
+    supportsChannelFundMax = () => true;
     supportsLSPS1customMessage = () => false;
     supportsLSPS1rest = () => true;
     supportsOffers = (): Promise<boolean> | boolean => false;

backends/LightningNodeConnect.ts

@@ -543,6 +543,7 @@ export default class LightningNodeConnect {
     supportsOnchainSendMax = () => this.supports('v0.18.3');
     supportsOnchainBatching = () => true;
     supportsChannelBatching = () => true;
+    supportsChannelFundMax = () => true;
     supportsLSPS1customMessage = () => false;
     supportsLSPS1rest = () => true;
     supportsOffers = () => false;

utils/BackendUtils.ts

@@ -175,6 +175,7 @@ class BackendUtils {
     supportsOnchainSendMax = () => this.call('supportsOnchainSendMax');
     supportsOnchainBatching = () => this.call('supportsOnchainBatching');
     supportsChannelBatching = () => this.call('supportsChannelBatching');
+    supportsChannelFundMax = () => this.call('supportsChannelFundMax');
     supportsOffers = () => this.call('supportsOffers');
     supportsBolt11BlindedRoutes = () =>
         this.call('supportsBolt11BlindedRoutes');

views/OpenChannel.tsx

@@ -604,7 +604,7 @@ export default class OpenChannel extends React.Component<
                                     </View>
                                 )}
 
-                                {BackendUtils.isLNDBased() &&
+                                {BackendUtils.supportsChannelFundMax() &&
                                     additionalChannels.length === 0 && (
                                         <>
                                             <Text