Fix test that was failing intermittently

Give test more time to complete but do not increase
sleep time more than necessary, by introducing
waiting loop for test purposes.

tests/codex/blockexchange/engine/testblockexc.nim

@@ -120,9 +120,8 @@ suite "NetworkStore engine - 2 nodes":
       .engine
       .taskQueue
       .pushOrUpdateNoWait(peerCtx1).isOk
-    await sleepAsync(100.millis)
 
-    check nodeCmps1.localStore.hasBlock(blk.cid)
+    check eventually nodeCmps1.localStore.hasBlock(blk.cid)
 
   test "Should get blocks from remote":
     let blocks = await allFinished(
@@ -148,11 +147,10 @@ suite "NetworkStore engine - 2 nodes":
     let blocks = await allFinished(
       blocks2.mapIt( nodeCmps1.networkStore.getBlock(it.cid) ))
 
-    await sleepAsync(100.millis)
+    let channel = !peerCtx1.paymentChannel
+    let wallet = nodeCmps2.wallet
 
-    let
-      channel = !peerCtx1.paymentChannel
-    check nodeCmps2.wallet.balance(channel, Asset) > 0
+    check eventually wallet.balance(channel, Asset) > 0
 
 suite "NetworkStore - multiple nodes":
   let

tests/codex/helpers.nim

@@ -9,8 +9,9 @@ import pkg/codex/rng
 import ./helpers/nodeutils
 import ./helpers/randomchunker
 import ./helpers/mockdiscovery
+import ./helpers/eventually
 
-export randomchunker, nodeutils, mockdiscovery
+export randomchunker, nodeutils, mockdiscovery, eventually
 
 # NOTE: The meaning of equality for blocks
 # is changed here, because blocks are now `ref`

tests/codex/helpers/eventually.nim

@@ -0,0 +1,13 @@
+import pkg/chronos
+
+template eventually*(condition: untyped, timeout = 5.seconds): bool =
+  proc loop: Future[bool] {.async.} =
+    let start = Moment.now()
+    while true:
+      if condition:
+        return true
+      if Moment.now() > (start + timeout):
+        return false
+      else:
+        await sleepAsync(1.millis)
+  await loop()