Fix set-individual-freeze when trustline exists

content/_code-samples/freeze/set-individual-freeze.js

@@ -10,10 +10,10 @@ async function main() {
     console.log(errorCode + ': ' + errorMessage);
   });
 
+  // Generates a test account
   const { wallet, balance } = await client.fundWallet()
-  const issuing_address = wallet.classicAddress
 
-  //const issuing_address = 'rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn';
+  const issuing_address = wallet.classicAddress
   const address_to_freeze = 'rUpy3eEg8rqjqfUoLeBnZkscbKbFsKXC3v';
   const currency_to_freeze = 'USD';
 
@@ -24,39 +24,56 @@ async function main() {
     peer: address_to_freeze,
   };
 
-  console.log('looking up', currency_to_freeze, 'trust line from',
+  console.log('Looking up', currency_to_freeze, 'trust line from',
               issuing_address, 'to', address_to_freeze);
 
   const data = await client.request(account_lines)
+  const trustlines = data.result.lines
 
-  let trustset = {};
-  if (data.length !== 1) {
-    console.log('trustline not found, making a default one');
+  // There can only be one trust line per currency code per account, 
+  // so we stop after the first match
+  let trustline = null;
+  for (let i = 0; i < trustlines.length; i++) {
+    if(trustlines[i].currency === currency_to_freeze) {
+      trustline = trustlines[i]
+      break
+    }
+  }
 
-    // Prepare a TrustSet transaction to create a trust line
-    trustset = {
-      TransactionType: 'TrustSet',
-      Account: issuing_address,
-      LimitAmount: {
+  let limit = null;
+  if(trustline === null) {
+    console.log('Trustline not found, making a default one');
+    
+    limit = {
       value: '0',
       currency: currency_to_freeze,
       issuer: address_to_freeze,
     }
-    };
-
-    // For JS users, this lets you check if your transaction is well-formed
-    validate(trustset) 
-
   } else {
-    trustset = data[0].specification;
-    console.log('trustline found. previous state:', trustline);
+    console.log('Found existing trustline: ', trustline)
+
+    limit = {
+      value: trustline.limit,
+      currency: trustline.currency,
+      issuer: trustline.account
+    }
   }
 
-  trustset.Flags = xrpl.TrustSetFlags.tfSetFreeze;
+  const trust_set = {
+    TransactionType: 'TrustSet',
+    Account: issuing_address,
+    LimitAmount: limit,
+    // Signal to freeze the individual trust line
+    Flags: xrpl.TrustSetFlags.tfSetFreeze
+  }
 
-  console.log('submitting tx:', trustset);
-  await client.submitReliable(wallet, trustset)
+  // For JS users, validate lets you check if your transaction is well-formed
+  validate(trust_set) 
 
+  console.log('Submitting TrustSet tx:', trust_set);
+  const result = await client.submitReliable(wallet, trust_set)
+
+  console.log('Submitted tx!')
   client.disconnect()
 }