fix: handle missing ProvideBufLen in bitswap stat response

kubo API doesn't return ProvideBufLen field in JSON response,
default to 0 when missing to fix test failure

Author: lidel

src/bitswap/stat.ts

@@ -18,7 +18,7 @@ export function createStat (client: HTTPRPCClient): BitswapAPI['stat'] {
 
 function toCoreInterface (res: any): BitswapStats {
   return {
-    provideBufLen: res.ProvideBufLen,
+    provideBufLen: res.ProvideBufLen ?? 0,
     wantlist: (res.Wantlist ?? []).map((k: any) => CID.parse(k['/'])),
     peers: (res.Peers ?? []).map((str: any) => peerIdFromString(str)),
     blocksReceived: BigInt(res.BlocksReceived),

test/interface-tests/src/stats/utils.ts

@@ -20,7 +20,7 @@ export function expectIsBitswap (err: Error | null, stats: BitswapStats): void {
   expect(stats).to.have.a.property('dupBlksReceived')
   expect(stats).to.have.a.property('dupDataReceived')
 
-  expect(stats.provideBufLen).to.a('number')
+  expect(stats.provideBufLen).to.a('number') // Defaults to 0 if not provided by API
   expect(stats.wantlist).to.be.an('array')
   expect(stats.peers).to.be.an('array')
   expect(isBigInt(stats.blocksReceived)).to.eql(true)