feat(wasm-utxo): refactor parsed transaction type definitions

Update the ParsedInput/Output types to use stronger typing (non-optional
address fields) and more explicit null values instead of undefined.

Also add test coverage for OP_RETURN outputs in transaction parsing.

Issue: BTC-2652

Co-authored-by: llm-git <[email protected]>

Author: OttoAllmendinger

packages/wasm-utxo/js/fixedScriptWallet.ts

@@ -57,17 +57,17 @@ type ReplayProtection =
 export type ScriptId = { chain: number; index: number };
 
 export type ParsedInput = {
-  address?: string;
+  address: string;
   script: Uint8Array;
   value: bigint;
-  scriptId: ScriptId | undefined;
+  scriptId: ScriptId | null;
 };
 
 export type ParsedOutput = {
-  address?: string;
+  address: string | null;
   script: Uint8Array;
   value: bigint;
-  scriptId?: ScriptId;
+  scriptId: ScriptId | null;
 };
 
 export type ParsedTransaction = {

packages/wasm-utxo/src/fixed_script_wallet/bitgo_psbt/psbt_wallet_input.rs

@@ -280,7 +280,7 @@ pub struct ScriptId {
 /// Parsed input from a PSBT transaction
 #[derive(Debug, Clone)]
 pub struct ParsedInput {
-    pub address: Option<String>,
+    pub address: String,
     pub script: Vec<u8>,
     pub value: u64,
     pub script_id: Option<ScriptId>,
@@ -333,7 +333,7 @@ impl ParsedInput {
             output_script.as_script(),
             network,
         )
-        .ok();
+        .map_err(ParseInputError::Address)?;
 
         Ok(Self {
             address,

packages/wasm-utxo/test/fixedScript/parseTransactionWithWalletKeys.ts

@@ -97,7 +97,19 @@ describe("parseTransactionWithWalletKeys", function () {
         const internalOutputs = parsed.outputs.filter((o) => o.scriptId);
 
         // Count external outputs (scriptId is null or undefined)
-        const externalOutputs = parsed.outputs.filter((o) => !o.scriptId);
+        const externalOutputs = parsed.outputs.filter((o) => o.scriptId === null);
+
+        assert.ok(externalOutputs.every((o) => o.address || o.script));
+        const nonAddressOutputs = externalOutputs.filter((o) => o.address === null);
+        assert.strictEqual(nonAddressOutputs.length, 1);
+        const [opReturnOutput] = nonAddressOutputs;
+        const expectedOpReturn = utxolib.payments.embed({
+          data: [Buffer.from("setec astronomy")],
+        }).output;
+        assert.strictEqual(
+          Buffer.from(opReturnOutput.script).toString("hex"),
+          expectedOpReturn.toString("hex"),
+        );
 
         // Fixtures now have 3 external outputs
         assert.ok(internalOutputs.length > 0, "Should have internal outputs (have scriptId)");