move error conversion from TransactionResponse to Confirmable

Ensures that provider no longer needs to know about error
conversion, it now localized in contract.nim.

Co-Authored-By: Eric Mastro <eric.mastro@gmail.com>

ethers/contract.nim

@@ -35,10 +35,10 @@ type
     gasLimit*: ?UInt256
   CallOverrides* = ref object of TransactionOverrides
     blockTag*: ?BlockTag
-
   ContractError* = object of EthersError
   Confirmable* = object
     response*: ?TransactionResponse
+    convert*: ConvertCustomErrors
   EventHandler*[E: Event] = proc(event: E) {.gcsafe, raises:[].}
 
 func new*(ContractType: type Contract,
@@ -124,14 +124,12 @@ proc call(contract: Contract,
 proc send(contract: Contract,
           function: string,
           parameters: tuple,
-          overrides = TransactionOverrides(),
+          overrides = TransactionOverrides()):
-          convertCustomErrors: ConvertCustomErrors = nil):
          Future[?TransactionResponse] {.async.} =
   if signer =? contract.signer:
     let transaction = createTransaction(contract, function, parameters, overrides)
     let populated = await signer.populateTransaction(transaction)
     var txResp = await signer.sendTransaction(populated)
-    txResp.convertCustomErrors = convertCustomErrors
     return txResp.some
   else:
     await call(contract, function, parameters, overrides)
@@ -229,9 +227,9 @@ func addContractCall(procedure: var NimNode) =
             "unexpected return type, " &
             "missing {.view.}, {.pure.} or {.getter.} ?"
           .}
+        let response = await send(`contract`, `function`, `parameters`, overrides)
         let convert = customErrorConversion(`errors`)
-        let response = await send(`contract`, `function`, `parameters`, overrides, convert)
+        Confirmable(response: response, convert: convert)
-        Confirmable(response: response)
 
   procedure[6] =
     if procedure.isConstant:
@@ -296,6 +294,21 @@ proc subscribe*[E: Event](contract: Contract,
 
   contract.provider.subscribe(filter, logHandler)
 
+proc confirm(tx: Confirmable, confirmations, timeout: int):
+  Future[TransactionReceipt] {.async.} =
+
+  without response =? tx.response:
+    raise newException(
+      EthersError,
+      "Transaction hash required. Possibly was a call instead of a send?"
+    )
+
+  try:
+    return await response.confirm(confirmations, timeout)
+  except ProviderError as error:
+    let convert = tx.convert
+    raise convert(error)
+
 proc confirm*(tx: Future[Confirmable],
               confirmations: int = EthersDefaultConfirmations,
               timeout: int = EthersReceiptTimeoutBlks):
@@ -305,13 +318,7 @@ proc confirm*(tx: Future[Confirmable],
   ## `await token.connect(signer0)
   ##          .mint(accounts[1], 100.u256)
   ##          .confirm(3)`
-  without response =? (await tx).response:
+  return await (await tx).confirm(confirmations, timeout)
-    raise newException(
-      EthersError,
-      "Transaction hash required. Possibly was a call instead of a send?"
-    )
-
-  return await response.confirm(confirmations, timeout)
 
 proc queryFilter[E: Event](contract: Contract,
                             _: type E,

ethers/errors/conversion.nim

@@ -2,6 +2,9 @@ import ../basics
 import ../provider
 import ./encoding
 
+type ConvertCustomErrors* =
+    proc(error: ref ProviderError): ref EthersError {.gcsafe, raises:[].}
+
 func customErrorConversion*(ErrorTypes: type tuple): ConvertCustomErrors =
   func convert(error: ref ProviderError): ref EthersError =
     if data =? error.data:

ethers/provider.nim

@@ -41,9 +41,6 @@ type
   TransactionResponse* = object
     provider*: Provider
     hash* {.serialize.}: TransactionHash
-    convertCustomErrors*: ConvertCustomErrors
-  ConvertCustomErrors* =
-    proc(error: ref ProviderError): ref EthersError {.gcsafe, raises:[].}
   TransactionReceipt* {.serialize.} = object
     sender* {.serialize("from"), deserialize("from").}: ?Address
     to*: ?Address
@@ -270,11 +267,7 @@ proc confirm*(
 
     if txBlockNumber + confirmations.u256 <= blockNumber + 1:
       await subscription.unsubscribe()
-      try:
       await tx.provider.ensureSuccess(receipt)
-      except ProviderError as error:
-        if convert =? tx.convertCustomErrors:
-          raise convert(error)
       return receipt
 
 proc confirm*(