Fix the return type of walkInvocationTree's callback to allow void …

…returns as intended (#765)

* Allow void returns on the walker as intended
* Add changelog entry

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+### Fixed
+* Fix the TypeScript definition of `walkInvocationTree` to allow void returns on the callback function as intended rather than forcing a `return null` ([#765](https://github.com/stellar/js-stellar-base/pull/765)).
+
 
 ## [`v12.1.0`](https://github.com/stellar/js-stellar-base/compare/v12.0.1...v12.1.0)
 

src/invocation.js

@@ -169,7 +169,8 @@ export function buildInvocationTree(root) {
  * @param {xdr.SorobanAuthorizedInvocation} [parent]  this `node`s parent node,
  *    if any (i.e. this doesn't exist at the root)
  *
- * @returns {boolean?}   returning `false` is a hint to stop exploring
+ * @returns {boolean|null|void}   returning exactly `false` is a hint to stop
+ *    exploring, other values are ignored
  */
 
 /**

types/index.d.ts

@@ -1258,7 +1258,7 @@ export type InvocationWalker = (
   node: xdr.SorobanAuthorizedInvocation,
   depth: number,
   parent?: any
-) => boolean|null;
+) => boolean|null|void;
 
 export function walkInvocationTree(
   root: xdr.SorobanAuthorizedInvocation,

types/test.ts

@@ -355,3 +355,9 @@ new StellarSdk.ScInt(BigInt(1234));   // $ExpectType ScInt
 (['i64', 'u64', 'i128', 'u128', 'i256', 'u256'] as StellarSdk.ScIntType[]).forEach((type) => {
   new StellarSdk.ScInt(1234, { type }); // $ExpectType ScInt
 });
+
+const root = new StellarSdk.xdr.SorobanAuthorizedInvocation({
+  function: new StellarSdk.xdr.SorobanAuthorizedFunction(),
+  subInvocations: [],
+});
+StellarSdk.walkInvocationTree(root, (_node, _depth, _parent) => {});