refactor: follow parse convention for wasm-solana

Remove `explainTransaction` from wasm-solana per the convention that
explain logic belongs in BitGoJS, not in wasm packages (PR #176).

- Delete `explain.ts` — type derivation, output/input extraction, fee
  calculation all move to BitGoJS sdk-coin-sol
- Change `parseTransaction` to accept a `Transaction` object instead
  of raw bytes, avoiding double deserialization when the caller already
  has a Transaction from `fromBytes()`
- Add `parse_from_transaction` Rust entry point that accepts a
  pre-deserialized Transaction, with shared logic in `parse_transaction_inner`
- Remove all explain-related exports from index.ts
  (ExplainedTransaction, TransactionType, StakingAuthorizeInfo, etc.)
- Fix pre-existing clippy warnings in intent/build.rs

The wasm package now only provides:
- `Transaction.fromBytes(bytes)` for deserialization/signing
- `parseTransaction(tx)` for decoded instruction data
- Builder functions for transaction construction

Ticket: BTC-3091

Author: lcovar

package-lock.json

@@ -9,7 +9,6 @@ export * as pubkey from "./pubkey.js";
 export * as transaction from "./transaction.js";
 export * as parser from "./parser.js";
 export * as builder from "./builder.js";
-export * as explain from "./explain.js";
 
 // Top-level class exports for convenience
 export { Keypair } from "./keypair.js";
@@ -24,8 +23,6 @@ export type { AddressLookupTableData } from "./versioned.js";
 export { parseTransaction } from "./parser.js";
 export { buildFromVersionedData } from "./builder.js";
 export { buildFromIntent, buildFromIntent as buildTransactionFromIntent } from "./intentBuilder.js";
-export { explainTransaction, TransactionType } from "./explain.js";
-
 // Intent builder type exports
 export type {
   BaseIntent,
@@ -99,16 +96,6 @@ export type {
   UnknownInstructionParams,
 } from "./parser.js";
 
-// Explain types
-export type {
-  ExplainedTransaction,
-  ExplainedOutput,
-  ExplainedInput,
-  ExplainOptions,
-  TokenEnablement,
-  StakingAuthorizeInfo,
-} from "./explain.js";
-
 // Versioned transaction builder type exports
 export type {
   AddressLookupTable as BuilderAddressLookupTable,

packages/wasm-solana/js/explain.ts

@@ -8,6 +8,7 @@
  */
 
 import { ParserNamespace } from "./wasm/wasm_solana.js";
+import type { Transaction } from "./transaction.js";
 
 // =============================================================================
 // Instruction Types - matching BitGoJS InstructionParams.
@@ -273,17 +274,24 @@ export interface ParsedTransaction {
 // =============================================================================
 
 /**
- * Parse raw transaction bytes into a plain data object with decoded instructions.
+ * Parse a Transaction into a plain data object with decoded instructions.
  *
  * This is the main parsing function that returns structured data with all
  * instructions decoded into semantic types (Transfer, StakingActivate, etc.)
  * with amounts as bigint.
  *
- * For signing/serialization, use `Transaction.fromBytes()` instead.
+ * Accepts a `Transaction` object (from `Transaction.fromBytes()`), avoiding
+ * double deserialization.
  *
- * @param bytes - Raw transaction bytes
+ * @param tx - A Transaction instance (from Transaction.fromBytes())
  * @returns A ParsedTransaction with all instructions decoded
+ *
+ * @example
+ * ```typescript
+ * const tx = Transaction.fromBytes(txBytes);
+ * const parsed = parseTransaction(tx);
+ * ```
  */
-export function parseTransaction(bytes: Uint8Array): ParsedTransaction {
-  return ParserNamespace.parse_transaction(bytes) as ParsedTransaction;
+export function parseTransaction(tx: Transaction): ParsedTransaction {
+  return ParserNamespace.parse_from_transaction(tx.wasm) as ParsedTransaction;
 }

packages/wasm-solana/js/index.ts

@@ -30,22 +30,23 @@ export interface Instruction {
  * Solana Transaction — deserialization wrapper for signing and serialization.
  *
  * Use `Transaction.fromBytes(bytes)` to create an instance for signing.
- * Use `parseTransaction(bytes)` from parser.ts to get decoded instruction data.
+ * Use `parseTransaction(tx)` from parser.ts to get decoded instruction data.
  *
  * @example
  * ```typescript
  * import { Transaction, parseTransaction } from '@bitgo/wasm-solana';
  *
+ * const tx = Transaction.fromBytes(txBytes);
+ *
  * // Parse for decoded instructions
- * const parsed = parseTransaction(txBytes);
+ * const parsed = parseTransaction(tx);
  * for (const instr of parsed.instructionsData) {
  *   if (instr.type === 'Transfer') {
  *     console.log(`${instr.amount} lamports to ${instr.toAddress}`);
  *   }
  * }
  *
- * // Deserialize for signing
- * const tx = Transaction.fromBytes(txBytes);
+ * // Sign and serialize
  * tx.addSignature(pubkey, signature);
  * const signedBytes = tx.toBytes();
  * ```

packages/wasm-solana/js/parser.ts

@@ -313,8 +313,7 @@ fn build_jito_stake(
     // For Jito, validatorAddress is the stake pool address
     let stake_pool: Pubkey = config
         .stake_pool_address
-        .as_ref()
-        .map(|s| s.as_str())
+        .as_deref()
         .unwrap_or(validator_address)
         .parse()
         .map_err(|_| WasmSolanaError::new("Invalid stakePoolAddress"))?;
@@ -1156,7 +1155,7 @@ mod tests {
             .transaction
             .signatures
             .iter()
-            .filter(|s| s.as_ref() != &zero_sig)
+            .filter(|s| s.as_ref() != zero_sig)
             .count();
         assert_eq!(
             non_zero_count, 1,

packages/wasm-solana/js/transaction.ts

@@ -9,6 +9,7 @@
 
 use crate::instructions::{decode_instruction, InstructionContext, ParsedInstruction};
 use crate::js_obj;
+use crate::transaction::Transaction;
 use crate::versioned::VersionedTransactionExt;
 use crate::wasm::try_into_js_value::{JsConversionError, TryIntoJsValue};
 use solana_message::VersionedMessage;
@@ -91,20 +92,52 @@ pub fn parse_transaction(bytes: &[u8]) -> Result<ParsedTransaction, String> {
     {
         VersionedMessage::Legacy(msg) => (
             msg.account_keys.iter().map(|k| k.to_string()).collect(),
-            &msg.instructions,
+            &msg.instructions[..],
             msg.recent_blockhash.to_string(),
             msg.header.num_required_signatures,
         ),
         VersionedMessage::V0(msg) => (
             msg.account_keys.iter().map(|k| k.to_string()).collect(),
-            &msg.instructions,
+            &msg.instructions[..],
             msg.recent_blockhash.to_string(),
             msg.header.num_required_signatures,
         ),
     };
 
-    let account_keys: Vec<String> = account_keys;
+    parse_transaction_inner(
+        account_keys,
+        instructions,
+        recent_blockhash,
+        num_required_signatures,
+        &tx.signatures,
+    )
+}
+
+/// Parse a pre-deserialized legacy Transaction into structured data.
+///
+/// Same logic as `parse_transaction(bytes)` but skips deserialization.
+/// Used when the caller already has a `Transaction` from `fromBytes()`.
+pub fn parse_from_transaction(tx: &Transaction) -> Result<ParsedTransaction, String> {
+    let msg = &tx.message;
+    let account_keys: Vec<String> = msg.account_keys.iter().map(|k| k.to_string()).collect();
+
+    parse_transaction_inner(
+        account_keys,
+        &msg.instructions,
+        msg.recent_blockhash.to_string(),
+        msg.header.num_required_signatures,
+        &tx.signatures,
+    )
+}
 
+/// Shared parsing logic for both bytes-based and Transaction-based entry points.
+fn parse_transaction_inner(
+    account_keys: Vec<String>,
+    instructions: &[solana_message::compiled_instruction::CompiledInstruction],
+    recent_blockhash: String,
+    num_required_signatures: u8,
+    signatures: &[solana_signature::Signature],
+) -> Result<ParsedTransaction, String> {
     // Extract fee payer (first account key)
     let fee_payer = account_keys
         .first()
@@ -156,8 +189,7 @@ pub fn parse_transaction(bytes: &[u8]) -> Result<ParsedTransaction, String> {
     // Extract signatures as base58 strings.
     // All-zeros signatures (unsigned placeholder slots) are returned as empty strings
     // so the JS side can simply use `signatures[0] || 'UNAVAILABLE'`.
-    let signatures: Vec<String> = tx
-        .signatures
+    let signatures: Vec<String> = signatures
         .iter()
         .map(|s| {
             let bytes: &[u8] = s.as_ref();

packages/wasm-solana/src/intent/build.rs

@@ -1,9 +1,10 @@
 //! WASM binding for high-level transaction parsing.
 //!
-//! Exposes a single `parseTransaction` function that returns fully decoded
+//! Exposes transaction parsing functions that return fully decoded
 //! transaction data matching BitGoJS's TxData format.
 
 use crate::parser;
+use crate::wasm::transaction::WasmTransaction;
 use crate::wasm::try_into_js_value::TryIntoJsValue;
 use wasm_bindgen::prelude::*;
 
@@ -38,4 +39,22 @@ impl ParserNamespace {
             .try_to_js_value()
             .map_err(|e| JsValue::from_str(&format!("Conversion error: {}", e)))
     }
+
+    /// Parse a pre-deserialized Transaction into structured data.
+    ///
+    /// Same as `parse_transaction(bytes)` but accepts an already-deserialized
+    /// WasmTransaction, avoiding double deserialization when the caller already
+    /// has a Transaction from `fromBytes()`.
+    ///
+    /// @param tx - A WasmTransaction instance
+    /// @returns A ParsedTransaction object
+    #[wasm_bindgen]
+    pub fn parse_from_transaction(tx: &WasmTransaction) -> Result<JsValue, JsValue> {
+        let parsed =
+            parser::parse_from_transaction(tx.inner()).map_err(|e| JsValue::from_str(&e))?;
+
+        parsed
+            .try_to_js_value()
+            .map_err(|e| JsValue::from_str(&format!("Conversion error: {}", e)))
+    }
 }