From 47f1350652f58ea790b14c1f7d36f2033f3f57d9 Mon Sep 17 00:00:00 2001
From: Keith Ingram <kwingram25@gmail.com>
Date: Tue, 17 Dec 2019 11:21:19 -0500
Subject: [PATCH] Additional rpcContractCall guard (#1677)

* additional rpc guard

* isFunction

* isFunction
---
 packages/api-contract/src/base/Contract.ts |  2 +-
 packages/api-contract/src/base/util.ts     | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/packages/api-contract/src/base/Contract.ts b/packages/api-contract/src/base/Contract.ts
index 8a0cc99e0e..f6f9b30379 100644
--- a/packages/api-contract/src/base/Contract.ts
+++ b/packages/api-contract/src/base/Contract.ts
@@ -41,7 +41,7 @@ export default class Contract<ApiType extends ApiTypes> extends BaseWithTxAndRpc
 
     return {
       send: this.decorateMethod(
-        as === 'rpc'
+        as === 'rpc' && this.hasRpcContractsCall
           ? (account: IKeyringPair | string | AccountId | Address): ContractCallResult<'rpc'> => {
             return this.rpcContractsCall(
               createType(this.registry, 'ContractCallRequest', {
diff --git a/packages/api-contract/src/base/util.ts b/packages/api-contract/src/base/util.ts
index e3866a7541..668408ed72 100644
--- a/packages/api-contract/src/base/util.ts
+++ b/packages/api-contract/src/base/util.ts
@@ -7,7 +7,7 @@ import { ApiObject, ContractABIMessage, ContractABIPre, ContractBase, ContractMe
 import { RpcInterface } from '@polkadot/rpc-core/jsonrpc.types';
 import { Registry } from '@polkadot/types/types';
 
-import { assert, stringCamelCase } from '@polkadot/util';
+import { assert, isFunction, stringCamelCase } from '@polkadot/util';
 import Abi from '../Abi';
 
 export abstract class Base<ApiType extends ApiTypes> implements ContractBase<ApiType> {
@@ -66,13 +66,13 @@ export abstract class BaseWithTx<ApiType extends ApiTypes> extends Base<ApiType>
 }
 
 export abstract class BaseWithTxAndRpcCall<ApiType extends ApiTypes> extends BaseWithTx<ApiType> {
+  public get hasRpcContractsCall (): boolean {
+    return isFunction(this.api.rx.rpc.contracts?.call);
+  }
+
   protected get rpcContractsCall (): DecoratedRpc<'rxjs', RpcInterface>['contracts']['call'] {
+    assert(this.hasRpcContractsCall, 'You need to connect to a node with the contracts.call RPC method.');
+
     return this.api.rx.rpc.contracts.call;
   }
-
-  constructor (api: ApiObject<ApiType>, abi: ContractABIPre | Abi, decorateMethod: DecorateMethod<ApiType>) {
-    super(api, abi, decorateMethod);
-
-    assert(this.api.rx.rpc.contracts && this.api.rx.tx.contracts.call, 'You need to connect to a node with the contracts module, the metadata does not enable api.rpc.contracts.call on this instance');
-  }
 }