fix: checking for keystore file existence

tests/waku_rln_relay/test_rln_group_manager_onchain.nim

@@ -223,6 +223,13 @@ suite "Onchain group manager":
                                        rlnInstance: manager.rlnInstance)
     expect(ValueError): await manager2.init()
 
+  asyncTest "should error when keystore path and password are provided but file doesn't exist":
+    let manager = await setup()
+    manager.keystorePath = some("/inexistent/file")
+    manager.keystorePassword = some("password")
+
+    expect(CatchableError): await manager.init()
+
   asyncTest "startGroupSync: should start group sync":
     let manager = await setup()
 

waku/waku_rln_relay/group_manager/on_chain/group_manager.nim

@@ -4,6 +4,7 @@ else:
   {.push raises: [].}
 
 import
+  os,
   web3,
   web3/ethtypes,
   eth/keys as keys,
@@ -623,37 +624,41 @@ method init*(g: OnchainGroupManager): Future[void] {.async.} =
   g.registryContract = some(registryContract)
 
   if g.keystorePath.isSome() and g.keystorePassword.isSome():
-    var keystoreQuery = KeystoreMembership(
-      membershipContract: MembershipContract(
-        chainId: $g.chainId.get(),
-        address: g.ethContractAddress
+    if existsFile(g.keystorePath.get()):
+      var keystoreQuery = KeystoreMembership(
+        membershipContract: MembershipContract(
+          chainId: $g.chainId.get(),
+          address: g.ethContractAddress
+        )
       )
-    )
-    if g.membershipIndex.isSome():
-      keystoreQuery.treeIndex = MembershipIndex(g.membershipIndex.get())
-    waku_rln_membership_credentials_import_duration_seconds.nanosecondTime:
-      let keystoreCredRes = getMembershipCredentials(path = g.keystorePath.get(),
-                                                     password = g.keystorePassword.get(),
-                                                     query = keystoreQuery,
-                                                     appInfo = RLNAppInfo)
-    if keystoreCredRes.isErr():
-      raise newException(CatchableError, "could not parse the keystore: " & $keystoreCredRes.error)
-    let keystoreCred = keystoreCredRes.get()
-    g.membershipIndex = some(keystoreCred.treeIndex)
-    when defined(rln_v2):
-      g.userMessageLimit = some(keystoreCred.userMessageLimit)
-    # now we check on the contract if the commitment actually has a membership
-    try:
-      let membershipExists = await rlnContract.memberExists(keystoreCred
-                                                            .identityCredential
-                                                            .idCommitment.toUInt256()).call()
-      if membershipExists == 0:
-        raise newException(CatchableError, "the provided commitment does not have a membership")
-    except CatchableError:
-      raise newException(CatchableError, "could not check if the commitment exists on the contract: " &
-                                         getCurrentExceptionMsg())
-
-    g.idCredentials = some(keystoreCred.identityCredential)
+      if g.membershipIndex.isSome():
+        keystoreQuery.treeIndex = MembershipIndex(g.membershipIndex.get())
+      waku_rln_membership_credentials_import_duration_seconds.nanosecondTime:
+        let keystoreCredRes = getMembershipCredentials(path = g.keystorePath.get(),
+                                                      password = g.keystorePassword.get(),
+                                                      query = keystoreQuery,
+                                                      appInfo = RLNAppInfo)
+      if keystoreCredRes.isErr():
+        raise newException(CatchableError, "could not parse the keystore: " & $keystoreCredRes.error)
+      let keystoreCred = keystoreCredRes.get()
+      g.membershipIndex = some(keystoreCred.treeIndex)
+      when defined(rln_v2):
+        g.userMessageLimit = some(keystoreCred.userMessageLimit)
+      # now we check on the contract if the commitment actually has a membership
+      try:
+        let membershipExists = await rlnContract.memberExists(keystoreCred
+                                                              .identityCredential
+                                                              .idCommitment.toUInt256()).call()
+        if membershipExists == 0:
+          raise newException(CatchableError, "the provided commitment does not have a membership")
+      except CatchableError:
+        raise newException(CatchableError, "could not check if the commitment exists on the contract: " &
+                                          getCurrentExceptionMsg())
+
+      g.idCredentials = some(keystoreCred.identityCredential)
+    else:
+      error "File provided as keystore path does not exist", path=g.keystorePath.get() 
+      raise newException(CatchableError, "missing keystore")
 
   let metadataGetRes = g.rlnInstance.getMetadata()
   if metadataGetRes.isErr():