Throw and handle errors from Providers.

In web3 wrapper when a response contains an error field we throw this rather than return response.result which is often undefined.
In Signature Utils we handle the error thrown when a user rejects the signing dialogue to prevent double signing.
Exposed the ZeroExTransaction JSON schema.
In Website only use the MetamaskSubprovider if we can detect the provider is Metamask

1 files changed, 7 insertions, 1 deletions

diff --git a/packages/subproviders/src/index.ts b/packages/subproviders/src/index.ts
index 6a8100e68..9f4dac58b 100644
--- a/packages/subproviders/src/index.ts
+++ b/packages/subproviders/src/index.ts
@@ -57,4 +57,10 @@ export {
     EIP712Parameter,
 } from '@0xproject/types';
 
-export { JSONRPCRequestPayload, Provider, JSONRPCResponsePayload, JSONRPCErrorCallback } from 'ethereum-types';
+export {
+    JSONRPCRequestPayload,
+    Provider,
+    JSONRPCResponsePayload,
+    JSONRPCErrorCallback,
+    JSONRPCResponseError,
+} from 'ethereum-types';