feat(wasm-solana): add Transaction.id getter

Add id getter to Transaction and VersionedTransaction classes.
Returns the first signature as base58, or "UNSIGNED" if no valid signature.

Ticket: BTC-3002

Author: lcovar

packages/wasm-solana/js/transaction.ts

@@ -87,6 +87,23 @@ export class Transaction {
     return this._wasm.num_signatures;
   }
 
+  /**
+   * Get the transaction ID (first signature as base58).
+   *
+   * For Solana, the transaction ID is the first signature.
+   * Returns "UNSIGNED" if the transaction has no valid signatures.
+   *
+   * @example
+   * ```typescript
+   * const tx = Transaction.fromBytes(txBytes);
+   * tx.addSignature(pubkey, signature);
+   * console.log(tx.id); // Base58 encoded signature
+   * ```
+   */
+  get id(): string {
+    return this._wasm.id;
+  }
+
   /**
    * Get the signable message payload (what gets signed)
    * This is the serialized message that signers sign

packages/wasm-solana/js/versioned.ts

@@ -168,6 +168,16 @@ export class VersionedTransaction {
     return this.inner.num_signatures;
   }
 
+  /**
+   * Get the transaction ID (first signature as base58).
+   *
+   * For Solana, the transaction ID is the first signature.
+   * Returns "UNSIGNED" if the transaction has no valid signatures.
+   */
+  get id(): string {
+    return this.inner.id;
+  }
+
   /**
    * Get the signable message payload.
    */

packages/wasm-solana/src/wasm/transaction.rs

@@ -9,6 +9,7 @@ use crate::error::WasmSolanaError;
 use crate::transaction::{Transaction, TransactionExt};
 use crate::versioned::{detect_transaction_version, TxVersion, VersionedTransactionExt};
 use solana_message::VersionedMessage;
+use solana_sdk::bs58;
 use solana_transaction::versioned::VersionedTransaction;
 use wasm_bindgen::prelude::*;
 
@@ -56,6 +57,24 @@ impl WasmTransaction {
         self.inner.num_signatures()
     }
 
+    /// Get the transaction ID (first signature as base58).
+    ///
+    /// For Solana, the transaction ID is the first signature.
+    /// Returns "UNSIGNED" if the first signature is all zeros (unsigned transaction).
+    #[wasm_bindgen(getter)]
+    pub fn id(&self) -> String {
+        if let Some(sig) = self.inner.signatures.first() {
+            let bytes: &[u8] = sig.as_ref();
+            // Check if signature is all zeros (unsigned)
+            if bytes.iter().all(|&b| b == 0) {
+                return "UNSIGNED".to_string();
+            }
+            bs58::encode(bytes).into_string()
+        } else {
+            "UNSIGNED".to_string()
+        }
+    }
+
     /// Get the signable message payload (what gets signed).
     ///
     /// This is the serialized message that signers sign.
@@ -242,6 +261,24 @@ impl WasmVersionedTransaction {
         self.inner.num_signatures()
     }
 
+    /// Get the transaction ID (first signature as base58).
+    ///
+    /// For Solana, the transaction ID is the first signature.
+    /// Returns "UNSIGNED" if the first signature is all zeros (unsigned transaction).
+    #[wasm_bindgen(getter)]
+    pub fn id(&self) -> String {
+        if let Some(sig) = self.inner.signatures.first() {
+            let bytes: &[u8] = sig.as_ref();
+            // Check if signature is all zeros (unsigned)
+            if bytes.iter().all(|&b| b == 0) {
+                return "UNSIGNED".to_string();
+            }
+            bs58::encode(bytes).into_string()
+        } else {
+            "UNSIGNED".to_string()
+        }
+    }
+
     /// Get the signable message payload.
     #[wasm_bindgen]
     pub fn signable_payload(&self) -> js_sys::Uint8Array {

packages/wasm-solana/test/transaction.ts

@@ -126,6 +126,29 @@ describe("Transaction", () => {
     assert.strictEqual(instr.programId, "11111111111111111111111111111111");
   });
 
+  describe("id getter", () => {
+    it("should return UNSIGNED for unsigned transaction", () => {
+      const tx = Transaction.fromBytes(TEST_TX_BYTES);
+      // The test transaction has an all-zeros signature (unsigned)
+      assert.strictEqual(tx.id, "UNSIGNED");
+    });
+
+    it("should return base58 signature after signing", () => {
+      const tx = Transaction.fromBytes(TEST_TX_BYTES);
+      const feePayer = tx.feePayer;
+
+      // Add a non-zero signature
+      const signature = new Uint8Array(64);
+      for (let i = 0; i < 64; i++) signature[i] = i + 1;
+      tx.addSignature(feePayer, signature);
+
+      // ID should now be a base58-encoded string of the signature
+      const id = tx.id;
+      assert.notStrictEqual(id, "UNSIGNED");
+      assert.ok(id.length > 20); // base58 encoded 64 bytes should be ~80+ chars
+    });
+  });
+
   describe("signerIndex", () => {
     it("should return signer index for fee payer", () => {
       const tx = Transaction.fromBytes(TEST_TX_BYTES);

packages/wasm-solana/test/versioned.ts

@@ -92,4 +92,27 @@ describe("VersionedTransaction", () => {
       assert.strictEqual(tx.feePayer, tx2.feePayer);
     });
   });
+
+  describe("id getter", () => {
+    it("should return UNSIGNED for unsigned transaction", () => {
+      const tx = VersionedTransaction.fromBase64(LEGACY_TX_BASE64);
+      // The test transaction has an all-zeros signature (unsigned)
+      assert.strictEqual(tx.id, "UNSIGNED");
+    });
+
+    it("should return base58 signature after signing", () => {
+      const tx = VersionedTransaction.fromBase64(LEGACY_TX_BASE64);
+      const feePayer = tx.feePayer;
+
+      // Add a non-zero signature
+      const signature = new Uint8Array(64);
+      for (let i = 0; i < 64; i++) signature[i] = i + 1;
+      tx.addSignature(feePayer, signature);
+
+      // ID should now be a base58-encoded string of the signature
+      const id = tx.id;
+      assert.notStrictEqual(id, "UNSIGNED");
+      assert.ok(id.length > 20); // base58 encoded 64 bytes should be ~80+ chars
+    });
+  });
 });