feat(sdk-coin-flrp): add sourceChain and destinationChain properties

modules/sdk-coin-flrp/src/lib/transaction.ts

@@ -254,9 +254,96 @@ export class Transaction extends BaseTransaction {
       signatures: this.signature,
       outputs: this.outputs,
       changeOutputs: this.changeOutputs,
+      sourceChain: this.sourceChain,
+      destinationChain: this.destinationChain,
     };
   }
 
+  /**
+   * Get the source chain id or undefined if it's not a cross chain transfer.
+   */
+  get sourceChain(): string | undefined {
+    const tx = (this._flareTransaction as UnsignedTx).getTx();
+
+    switch (this.type) {
+      case TransactionType.Import:
+        if (this.isTransactionForCChain) {
+          // C-chain Import: source is the chain we're importing FROM (P-chain)
+          const importTx = tx as evmSerial.ImportTx;
+          return this.blockchainIDtoAlias(Buffer.from(importTx.sourceChain.toBytes()));
+        } else {
+          // P-chain Import: source is the chain we're importing FROM (C-chain)
+          const pvmImportTx = tx as pvmSerial.ImportTx;
+          return this.blockchainIDtoAlias(Buffer.from(pvmImportTx.sourceChain.toBytes()));
+        }
+
+      case TransactionType.Export:
+        if (this.isTransactionForCChain) {
+          // C-chain Export: source is C-chain (the blockchain ID)
+          const exportTx = tx as evmSerial.ExportTx;
+          return this.blockchainIDtoAlias(Buffer.from(exportTx.blockchainId.toBytes()));
+        } else {
+          // P-chain Export: source is P-chain (the blockchain ID from baseTx)
+          const pvmExportTx = tx as pvmSerial.ExportTx;
+          return this.blockchainIDtoAlias(Buffer.from(pvmExportTx.baseTx.BlockchainId.toBytes()));
+        }
+
+      default:
+        return undefined;
+    }
+  }
+
+  /**
+   * Get the destination chain id or undefined if it's not a cross chain transfer.
+   */
+  get destinationChain(): string | undefined {
+    const tx = (this._flareTransaction as UnsignedTx).getTx();
+
+    switch (this.type) {
+      case TransactionType.Import:
+        if (this.isTransactionForCChain) {
+          // C-chain Import: destination is C-chain (the blockchain ID)
+          const importTx = tx as evmSerial.ImportTx;
+          return this.blockchainIDtoAlias(Buffer.from(importTx.blockchainId.toBytes()));
+        } else {
+          // P-chain Import: destination is P-chain (the blockchain ID from baseTx)
+          const pvmImportTx = tx as pvmSerial.ImportTx;
+          return this.blockchainIDtoAlias(Buffer.from(pvmImportTx.baseTx.BlockchainId.toBytes()));
+        }
+
+      case TransactionType.Export:
+        if (this.isTransactionForCChain) {
+          // C-chain Export: destination is P-chain (the destination chain)
+          const exportTx = tx as evmSerial.ExportTx;
+          return this.blockchainIDtoAlias(Buffer.from(exportTx.destinationChain.toBytes()));
+        } else {
+          // P-chain Export: destination is C-chain (the destination chain)
+          const pvmExportTx = tx as pvmSerial.ExportTx;
+          return this.blockchainIDtoAlias(Buffer.from(pvmExportTx.destination.toBytes()));
+        }
+
+      default:
+        return undefined;
+    }
+  }
+
+  /**
+   * Convert a blockchainId buffer to string and return P or C alias if it matches any of those chains.
+   * @param {Buffer} blockchainIDBuffer
+   * @return {string} blockchainID or alias if exists.
+   * @private
+   */
+  private blockchainIDtoAlias(blockchainIDBuffer: Buffer): string {
+    const blockchainId = utils.cb58Encode(blockchainIDBuffer);
+    if (blockchainId === this._network.cChainBlockchainID) {
+      return 'C';
+    }
+    if (blockchainId === this._network.blockchainID) {
+      return 'P';
+    }
+    return blockchainId;
+  }
+
   setTransaction(tx: Tx): void {
     this._flareTransaction = tx as UnsignedTx;
   }

modules/sdk-coin-flrp/test/unit/lib/transactionBuilderFactory.ts

@@ -0,0 +1,67 @@
+import 'should';
+import { coins } from '@bitgo/statics';
+import { TransactionBuilderFactory, TxData } from '../../../src/lib';
+import { EXPORT_IN_P } from '../../resources/transactionData/exportInP';
+import { IMPORT_IN_P } from '../../resources/transactionData/importInP';
+import { IMPORT_IN_C } from '../../resources/transactionData/importInC';
+import { EXPORT_IN_C } from '../../resources/transactionData/exportInC';
+
+describe('Flrp Transaction Builder Factory', () => {
+  const factory = new TransactionBuilderFactory(coins.get('tflrp'));
+
+  describe('Cross chain transfer has source and destination chains', () => {
+    // P-chain Export to C-chain: source is P, destination is C
+    const p2cExportTxs = [EXPORT_IN_P.unsignedHex, EXPORT_IN_P.halfSigntxHex, EXPORT_IN_P.fullSigntxHex];
+
+    // C-chain Import from P-chain: source is P, destination is C
+    const p2cImportTxs = [IMPORT_IN_C.unsignedHex, IMPORT_IN_C.halfSigntxHex, IMPORT_IN_C.fullSigntxHex];
+
+    // P-chain Import from C-chain: source is C, destination is P
+    const c2pImportTxs = [IMPORT_IN_P.unsignedHex, IMPORT_IN_P.halfSigntxHex, IMPORT_IN_P.fullSigntxHex];
+
+    // C-chain Export to P-chain: source is C, destination is P
+    const c2pExportTxs = [EXPORT_IN_C.unsignedHex, EXPORT_IN_C.signedHex];
+
+    async function toJson(txHex: string): Promise<TxData> {
+      const txBuilder = factory.from(txHex);
+      const tx = await txBuilder.build();
+      return tx.toJson();
+    }
+
+    describe('P to C chain transfers', () => {
+      it('Should have sourceChain P and destinationChain C for Export from P-chain', async () => {
+        for (const rawTx of p2cExportTxs) {
+          const txJson = await toJson(rawTx);
+          txJson.sourceChain!.should.equal('P');
+          txJson.destinationChain!.should.equal('C');
+        }
+      });
+
+      it('Should have sourceChain P and destinationChain C for Import to C-chain', async () => {
+        for (const rawTx of p2cImportTxs) {
+          const txJson = await toJson(rawTx);
+          txJson.sourceChain!.should.equal('P');
+          txJson.destinationChain!.should.equal('C');
+        }
+      });
+    });
+
+    describe('C to P chain transfers', () => {
+      it('Should have sourceChain C and destinationChain P for Import to P-chain', async () => {
+        for (const rawTx of c2pImportTxs) {
+          const txJson = await toJson(rawTx);
+          txJson.sourceChain!.should.equal('C');
+          txJson.destinationChain!.should.equal('P');
+        }
+      });
+
+      it('Should have sourceChain C and destinationChain P for Export from C-chain', async () => {
+        for (const rawTx of c2pExportTxs) {
+          const txJson = await toJson(rawTx);
+          txJson.sourceChain!.should.equal('C');
+          txJson.destinationChain!.should.equal('P');
+        }
+      });
+    });
+  });
+});