@0x/json-schemas: Rename CallData.value -> CallData.balance and make it `wholeNumberSchema type.'

`@0x/web3-wrapper`: Only supply overrides to eth_call RPC if provided.

packages/json-schemas/schemas/call_data_schema.json

@@ -27,13 +27,13 @@
                 "properties": {
                     "code": {
                         "type": "string",
-                        "pattern": "^0x[0-9a-f]*$"
+                        "pattern": "^0x[0-9a-fA-F]*$"
                     },
                     "nonce": {
-                        "oneOf": [{ "$ref": "/numberSchema" }, { "$ref": "/jsNumberSchema" }]
+                        "oneOf": [{ "$ref": "/wholeNumberSchema" }]
                     },
-                    "value": {
-                        "oneOf": [{ "$ref": "/numberSchema" }, { "$ref": "/jsNumberSchema" }]
+                    "balance": {
+                        "oneOf": [{ "$ref": "/wholeNumberSchema" }]
                     }
                 }
             }

packages/web3-wrapper/src/marshaller.ts

@@ -180,8 +180,9 @@ export const marshaller = {
         for (const address in overrides) {
             if (address) {
                 const override = overrides[address];
+                const marshalledAddress = marshaller.marshalAddress(address);
                 const marshalledOverride: GethCallOverridesRPC[keyof GethCallOverridesRPC] = (marshalled[
-                    marshaller.marshalAddress(address)
+                    marshalledAddress
                 ] = {});
                 if (override.code !== undefined) {
                     marshalledOverride.code = override.code;
@@ -192,6 +193,9 @@ export const marshaller = {
                 if (override.balance !== undefined) {
                     marshalledOverride.balance = utils.encodeAmountAsHexString(override.balance);
                 }
+                if (Object.keys(marshalledOverride).length === 0) {
+                    delete marshalled[marshalledAddress];
+                }
             }
         }
         return marshalled;

packages/web3-wrapper/src/web3_wrapper.ts

@@ -565,7 +565,7 @@ export class Web3Wrapper {
         const overrides = marshaller.marshalCallOverrides(callData.overrides || {});
         const rawCallResult = await this.sendRawPayloadAsync<string>({
             method: 'eth_call',
-            params: [callDataHex, marshalledDefaultBlock, overrides],
+            params: [callDataHex, marshalledDefaultBlock, ...(Object.keys(overrides).length === 0 ? [] : [overrides])],
         });
         return rawCallResult;
     }