gets rid of ugly casts

Author: marcinczenko

Diff for: codex/blockexchange/engine/advertiser.nim

@@ -86,7 +86,7 @@ proc advertiseLocalStoreLoop(b: Advertiser) {.async: (raises: []).} =
       if cidsIter =? await b.localStore.listBlocks(blockType = BlockType.Manifest):
         trace "Advertiser begins iterating blocks..."
         for c in cidsIter:
-          if cid =? (await cast[Future[?!Cid].Raising([CancelledError])](c)):
+          if cid =? await c:
             await b.advertiseBlock(cid)
         trace "Advertiser iterating blocks finished."
 

Diff for: codex/node.nim

@@ -485,7 +485,7 @@ proc iterateManifests*(self: CodexNodeRef, onManifest: OnManifest) {.async.} =
     return
 
   for c in cidsIter:
-    if cid =? (await cast[Future[?!Cid].Raising([CancelledError])](c)):
+    if cid =? await c:
       without blk =? await self.networkStore.getBlock(cid):
         warn "Failed to get manifest block by cid", cid
         return

Diff for: codex/stores/maintenance.nim

@@ -83,8 +83,7 @@ proc runBlockCheck(
 
   var numberReceived = 0
   for beFut in iter:
-    let beRes = await cast[Future[?!BlockExpiration].Raising([CancelledError])](beFut)
-    without be =? beRes, err:
+    without be =? (await beFut), err:
       trace "Unable to obtain blockExpiration from iterator"
       continue
     inc numberReceived

Diff for: tests/codex/stores/commonstoretests.nim

@@ -110,7 +110,7 @@ proc commonBlockStoreTests*(
 
       var count = 0
       for c in cidsIter:
-        if cid =? (await cast[Future[?!Cid].Raising([CancelledError])](c)):
+        if cid =? await c:
           check (await store.hasBlock(cid)).tryGet()
           count.inc
 
@@ -134,7 +134,7 @@ proc commonBlockStoreTests*(
 
       var count = 0
       for c in cidsIter:
-        if cid =? (await cast[Future[?!Cid].Raising([CancelledError])](c)):
+        if cid =? await c:
           check manifestBlock.cid == cid
           check (await store.hasBlock(cid)).tryGet()
           count.inc
@@ -159,7 +159,7 @@ proc commonBlockStoreTests*(
 
       var count = 0
       for c in cidsIter:
-        if cid =? (await cast[Future[?!Cid].Raising([CancelledError])](c)):
+        if cid =? await c:
           check (await store.hasBlock(cid)).tryGet()
           count.inc
 

Diff for: tests/codex/stores/testrepostore.nim

@@ -293,16 +293,13 @@ asyncchecksuite "RepoStore":
 
   test "Should retrieve block expiration information":
     proc unpack(
-        beIter: Future[?!SafeAsyncIter[BlockExpiration]]
+        beIter: auto
     ): Future[seq[BlockExpiration]] {.async: (raises: [CancelledError]).} =
       var expirations = newSeq[BlockExpiration](0)
-      without iter =? (
-        await cast[Future[?!SafeAsyncIter[BlockExpiration]].Raising([CancelledError])](beIter)
-      ), err:
+      without iter =? (await beIter), err:
         return expirations
       for beFut in toSeq(iter):
-        if value =?
-            (await cast[Future[?!BlockExpiration].Raising([CancelledError])](beFut)):
+        if value =? (await beFut):
           expirations.add(value)
       return expirations
 

Diff for: tests/codex/utils/testsafeasynciter.nim

@@ -356,7 +356,14 @@ asyncchecksuite "Test SafeAsyncIter":
       iter3.finished
 
   test "Should propagate cancellation error immediately":
-    let fut = newFuture[Option[?!string]]("testsafeasynciter")
+    proc newRaisingFuture[T](
+        fromProc: static[string] = ""
+    ): Future[T] {.async: (raw: true, raises: [CancelledError]).} =
+      let fut = newFuture[T](fromProc)
+      return fut
+
+    let fut: Future[Option[?!string]].Raising([CancelledError]) =
+      newRaisingFuture[Option[?!string]]("testsafeasynciter")
 
     let iter1 = SafeAsyncIter[int].new(0 ..< 5).delayBy(10.millis)
     let iter2 = await mapFilter[int, string](
@@ -365,7 +372,7 @@ asyncchecksuite "Test SafeAsyncIter":
         if i =? i:
           if (i < 3):
             return some(success($i))
-        return await cast[Future[Option[?!string]].Raising([CancelledError])](fut),
+        return await fut,
     )
 
     proc cancelFut(): Future[void] {.async.} =