Merge pull request #272 from OriginTrail/fix/approve-called-without-sufficient-TRAC

Fix for approve called without sufficient trac

Author: zsculac

package-lock.json

@@ -1,6 +1,6 @@
 {
     "name": "dkg.js",
-    "version": "8.2.3",
+    "version": "8.2.4",
     "description": "Javascript library for interaction with the OriginTrail Decentralized Knowledge Graph",
     "main": "index.js",
     "exports": {

package.json

@@ -510,6 +510,25 @@ export default class BlockchainServiceBase {
             if (requestData?.paymaster && requestData?.paymaster !== ZERO_ADDRESS) {
                 // Handle the case when payer is passed
             } else {
+                const senderBalance = await this.callContractFunction(
+                    'Token',
+                    'balanceOf',
+                    [sender],
+                    blockchain,
+                );
+
+                if (BigInt(senderBalance) < BigInt(requestData.tokenAmount)) {
+                    const balance = Number(senderBalance) / 1e18;
+                    const required = Number(requestData.tokenAmount) / 1e18;
+
+                    throw new Error(
+                        `Insufficient TRAC token balance to publish. ` +
+                            `Wallet ${sender} has ${balance} TRAC, ` +
+                            `but the publish operation requires ${required} TRAC. ` +
+                            `Please fund your wallet with more TRAC tokens to proceed.`,
+                    );
+                }
+
                 await this.increaseKnowledgeCollectionAllowance(
                     sender,
                     requestData.tokenAmount,