DEXTF: staked tokens (snapshot-labs#59)

Strategy to calculate number of staked DEXTF

Co-authored-by: Fabrizio Audisio <[email protected]>

src/strategies/dextf-staked-in-vaults/README.md

@@ -0,0 +1,42 @@
+# Multiple contract call strategy
+
+This strategy allows users to call the 'balanceOf' function across multiple DEXTF contracts (vaults) and performs summation over the results. By calling 'balanceOf', DEXTF vaults return the amount of $DEXTF staked by the user in that vault. This strategy will make a single multicall which will retrieve all users' staked balances in all of DEXTF vaults.
+
+## Example
+
+The space config will look like this:
+
+```JSON
+{
+  "strategies": [
+    ["dextf-staked-in-vaults", {
+      // vault contracts across which token balance needs to be calculated
+      "contractAddresses": [
+      "0x42a05787584ec09dDDe46f8CE6a715c93049ee88"
+      ],
+      // scoreMultiplier can be used to increase users' scores by a certain magnitude
+      "scoreMultiplier": 1,
+      // ABI for balanceOf method
+      "methodABI_1": {
+            "inputs": [
+              {
+                "internalType": "address",
+                "name": "account",
+                "type": "address"
+              }
+            ],
+            "name": "balanceOf",
+            "outputs": [
+              {
+                "internalType": "uint256",
+                "name": "",
+                "type": "uint256"
+              }
+            ],
+            "stateMutability": "view",
+            "type": "function"
+          }
+    }],
+  ]
+}
+```

src/strategies/dextf-staked-in-vaults/examples.json

@@ -0,0 +1,35 @@
+[
+  {
+    "name": "Example query",
+    "strategy": {
+      "name": "dextf-staked-in-vaults",
+      "params": {
+        "name": "DEXTF Vaults",
+        "contractAddresses": ["0x42a05787584ec09dDDe46f8CE6a715c93049ee88"],
+        "scoreMultiplier": 1,
+        "methodABI": {
+          "inputs": [
+            {
+              "internalType": "address",
+              "name": "account",
+              "type": "address"
+            }
+          ],
+          "name": "balanceOf",
+          "outputs": [
+            {
+              "internalType": "uint256",
+              "name": "",
+              "type": "uint256"
+            }
+          ],
+          "stateMutability": "view",
+          "type": "function"
+        }
+      }
+    },
+    "network": "1",
+    "addresses": ["0x75527f00EC786dCCd6CEa82C9B90C81781C42E92"],
+    "snapshot": 13230652
+  }
+]

src/strategies/dextf-staked-in-vaults/index.ts

@@ -0,0 +1,61 @@
+import { formatUnits } from '@ethersproject/units';
+import { multicall } from '../../utils';
+
+export const author = 'dextf';
+export const version = '1.0.0';
+
+function chunk(array, chunkSize) {
+  const tempArray: any[] = [];
+  for (let i = 0, len = array.length; i < len; i += chunkSize)
+    tempArray.push(array.slice(i, i + chunkSize));
+  return tempArray;
+}
+
+export async function strategy(
+  space,
+  network,
+  provider,
+  addresses,
+  options,
+  snapshot
+) {
+  const blockTag = typeof snapshot === 'number' ? snapshot : 'latest';
+  let callData: [any, string, [any]][] = [];
+  addresses.map((userAddress: any) => {
+    options.contractAddresses.map((vaultAddress: any) => {
+      callData.push([vaultAddress, options.methodABI.name, [userAddress]]);
+    });
+  });
+  callData = [...chunk(callData, 2000)]; // chunking the callData into multiple arrays of 2000 requests
+  let response: any[] = [];
+  for (let i = 0; i < callData.length; i++) {
+    const tempArray = await multicall(
+      network,
+      provider,
+      [options.methodABI],
+      callData[i],
+      { blockTag }
+    );
+    response.push(...tempArray);
+  }
+  if (options.contractAddresses.length > 1) {
+    // grouping all balances of a particular address together
+    const result: any = [];
+    response = [].concat.apply([], response);
+    for (let i = addresses.length; i > 0; i--) {
+      result.push(response.splice(0, Math.ceil(response.length / i)));
+    }
+    // performing summation over all balances of the user
+    response = [];
+    result.map((item, index) => {
+      let sum = 0;
+      result[index].map((element) => {
+        sum = sum + parseFloat(formatUnits(element.toString(), 18));
+      });
+      response.push(sum);
+    });
+  }
+  return Object.fromEntries(
+    response.map((value, i) => [addresses[i], options.scoreMultiplier * value])
+  );
+}

src/strategies/index.ts

@@ -6,6 +6,7 @@ import * as balancerErc20InternalBalanceOf from './balancer-erc20-internal-balan
 import * as sunder from './sunder';
 import * as balancerSmartPool from './balancer-smart-pool';
 import * as contractCall from './contract-call';
+import * as dextfVaults from './dextf-staked-in-vaults';
 import * as dfynFarms from './dfyn-staked-in-farms';
 import * as dfynVaults from './dfyn-staked-in-vaults';
 import * as ensDomainsOwned from './ens-domains-owned';
@@ -152,6 +153,7 @@ const strategies = {
   'balancer-erc20-internal-balance-of': balancerErc20InternalBalanceOf,
   'erc20-received': erc20Received,
   'contract-call': contractCall,
+  'dextf-staked-in-vaults': dextfVaults,
   'dfyn-staked-in-farms': dfynFarms,
   'dfyn-staked-in-vaults': dfynVaults,
   'eth-received': ethReceived,