Fix(subgraph): Arbitrable code was not implemented

subgraph/schema.graphql

@@ -67,7 +67,7 @@ type User @entity {
   evidences: [Evidence!]! @derivedFrom(field: "sender")
 }
 
-type Arbitrated @entity {
+type Arbitrable @entity {
   id: ID! # address
   disputes: [Dispute!]! @derivedFrom(field: "arbitrated")
   totalDisputes: BigInt!
@@ -114,7 +114,7 @@ type Court @entity {
 type Dispute @entity {
   id: ID!
   court: Court!
-  arbitrated: Arbitrated!
+  arbitrated: Arbitrable!
   period: Period!
   ruled: Boolean!
   lastPeriodChange: BigInt!

subgraph/src/KlerosCore.ts

@@ -37,6 +37,7 @@ import {
 } from "./entities/JurorTokensPerCourt";
 import { createDrawFromEvent } from "./entities/Draw";
 import { createTokenAndEthShiftFromEvent } from "./entities/TokenAndEthShift";
+import { updateArbitrableCases } from "./entities/Arbitrable";
 
 function getPeriodName(index: i32): string {
   const periodArray = ["evidence", "commit", "vote", "appeal", "execution"];
@@ -88,6 +89,8 @@ export function handleDisputeCreation(event: DisputeCreation): void {
   createDisputeFromEvent(event);
   const roundInfo = contract.getRoundInfo(disputeID, ZERO);
   createRoundFromRoundInfo(disputeID, ZERO, court.feeForJuror, roundInfo);
+  const arbitrable = event.params._arbitrable.toHexString();
+  updateArbitrableCases(arbitrable, ONE);
   updateCases(ONE, event.block.timestamp);
 }
 

subgraph/src/entities/Arbitrable.ts

@@ -0,0 +1,20 @@
+import { BigInt } from "@graphprotocol/graph-ts";
+import { Arbitrable } from "../../generated/schema";
+import { ZERO } from "../utils";
+
+export function ensureArbitrable(id: string): Arbitrable {
+  let arbitrable = Arbitrable.load(id);
+
+  if (arbitrable) return arbitrable;
+
+  arbitrable = new Arbitrable(id);
+  arbitrable.totalDisputes = ZERO;
+
+  return arbitrable;
+}
+
+export function updateArbitrableCases(id: string, delta: BigInt): void {
+  const arbitrable = ensureArbitrable(id);
+  arbitrable.totalDisputes = arbitrable.totalDisputes.plus(delta);
+  arbitrable.save();
+}