Review comments by Dmitriy, part 1

codex/codex.nim

@@ -272,7 +272,10 @@ proc new*(
     engine = BlockExcEngine.new(repoStore, wallet, network, blockDiscovery, peerStore, pendingBlocks)
     store = NetworkStore.new(engine, repoStore)
     prover = if config.prover:
-      some Prover.new(store, config).expect("Unable to create prover.")
+      let
+        backendFactory = BackendFactory()
+        backend = backendFactory.initializeBackend(config).expect("Unable to create prover backend.")
+      some Prover.new(store, backend, config)
     else:
       none Prover
 

codex/slots/proofs.nim

@@ -1,4 +1,5 @@
 import ./proofs/backends
 import ./proofs/prover
+import ./proofs/backendfactory
 
-export circomcompat, prover
+export circomcompat, prover, backendfactory

codex/slots/proofs/backendfactory.nim

@@ -11,6 +11,9 @@ import ../../conf
 import ./backends
 import ./backendutils
 
+type
+  BackendFactory* = object of RootObj
+
 proc initializeFromConfig(
   config: CodexConf,
   utils: BackendUtils): ?!AnyBackend =
@@ -70,6 +73,7 @@ proc suggestDownloadTool(config: CodexConf) =
   echo "'./" & tokens.join(" ") & "'"
 
 proc initializeBackend*(
+  self: BackendFactory,
   config: CodexConf,
   utils: BackendUtils = BackendUtils()): ?!AnyBackend =
 

codex/slots/proofs/prover.nim

@@ -92,13 +92,10 @@ proc verify*(
 proc new*(
   _: type Prover,
   store: BlockStore,
-  config: CodexConf): ?!Prover =
+  backend: AnyBackend,
+  config: CodexConf): Prover =
 
-  without backend =? initializeBackend(config), err:
-    error "Failed to initialize backend", msg = err.msg
-    return failure(err)
-
-  success Prover(
+  Prover(
     store: store,
     backend: backend,
     nSamples: config.numProofSamples)

tests/codex/slots/testbackendfactory.nim

@@ -36,6 +36,7 @@ suite "Test BackendFactory":
   let
     utilsMock = BackendUtilsMock()
     circuitDir = "testecircuitdir"
+    factory = BackendFactory()
 
   setup:
     createDir(circuitDir)
@@ -56,7 +57,7 @@ suite "Test BackendFactory":
         circomWasm: InputFile("tests/circuits/fixtures/proof_main.wasm"),
         circomZkey: InputFile("tests/circuits/fixtures/proof_main.zkey")
       )
-      backend = initializeBackend(config, utilsMock).tryGet
+      backend = factory.initializeBackend(config, utilsMock).tryGet
 
     check:
       backend.vkp != nil
@@ -78,7 +79,7 @@ suite "Test BackendFactory":
         # will be picked up as local files:
         circuitDir: OutDir("tests/circuits/fixtures")
       )
-      backend = initializeBackend(config, utilsMock).tryGet
+      backend = factory.initializeBackend(config, utilsMock).tryGet
 
     check:
       backend.vkp != nil
@@ -97,8 +98,7 @@ suite "Test BackendFactory":
         marketplaceAddress: EthAddress.example.some,
         circuitDir: OutDir(circuitDir)
       )
-
-      backendResult = initializeBackend(config, utilsMock)
+      backendResult = factory.initializeBackend(config, utilsMock)
 
     check:
       backendResult.isErr

tests/codex/slots/testprover.nim

@@ -53,8 +53,12 @@ suite "Test Prover":
         numProofSamples: samples
       )
 
+    let
+      backendFactory = BackendFactory()
+      backend = backendFactory.initializeBackend(config).tryGet()
+
     store = RepoStore.new(repoDs, metaDs)
-    prover = Prover.new(store, config).tryGet()
+    prover = Prover.new(store, backend, config)
 
   teardown:
     await repoTmp.destroyDb()