Create ERC721-With-Balance strategy

src/strategies/erc721-with-balance/README.md

@@ -0,0 +1,15 @@
+# erc721-with-balance
+
+This is a strategy to allow egalitarian voting power to holders of an ERC-721 token.
+
+A `minBalance` can be defined. It returns a voting power of `1` if the balance of the voter for a specific ERC-721 token is **greater than or equal** to the minBalance.
+
+Here is an example of parameters:
+
+```json
+{
+  "address": "0x25ed58c027921e14d86380ea2646e3a1b5c55a8b",
+  "symbol": "DEVS",
+  "minBalance": 1
+}
+```

src/strategies/erc721-with-balance/examples.json

@@ -0,0 +1,25 @@
+[
+  {
+    "name": "Example query with minimum ERC-721 balance",
+    "strategy": {
+      "name": "erc721-with-balance",
+      "params": {
+        "address": "0x25ed58c027921e14d86380ea2646e3a1b5c55a8b",
+        "symbol": "DEVS",
+        "minBalance": 1
+      }
+    },
+    "network": "1",
+    "addresses": [
+      "0x0000000000000000000000000000000000baddad",
+      "0x76da95534c57516625948baA9d069D5ed371b324",
+      "0xb1c015bc96958e42b670c502bc29be791e754127",
+      "0x03f9bc4648a98cdc61fca7a177d809edab2c14fc",
+      "0x27f8602e403b6ea18f8711a7858fa4a94ef3269b",
+      "0xa703b1cb89f50939173a124ba76571369cf69953",
+      "0x184e2d53a04bc87a6b597703edcd62d768da1f27",
+      "0xa4a13b3f22bc0e90235e17ae9343b2c7e04e96c8"
+    ],
+    "snapshot": 13647430
+  }
+]

src/strategies/erc721-with-balance/index.ts

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+import { formatUnits } from '@ethersproject/units';
+import { multicall } from '../../utils';
+
+export const author = 'WillBlackburn';
+export const version = '0.1.1';
+
+const abi = [
+  'function balanceOf(address account) external view returns (uint256)'
+];
+
+export async function strategy(
+  space,
+  network,
+  provider,
+  addresses,
+  options,
+  snapshot
+) {
+  const blockTag = typeof snapshot === 'number' ? snapshot : 'latest';
+  const response = await multicall(
+    network,
+    provider,
+    abi,
+    addresses.map((address: any) => [options.address, 'balanceOf', [address]]),
+    { blockTag }
+  );
+  return Object.fromEntries(
+    response.map((value, i) => [
+      addresses[i],
+      parseInt(formatUnits(value.toString(), 0)) >= (options.minBalance || 1) ? 1 : 0
+    ])
+  );
+}

src/strategies/index.ts

@@ -110,6 +110,7 @@ import * as xseen from './xseen';
 import * as molochAll from './moloch-all';
 import * as molochLoot from './moloch-loot';
 import * as erc721Enumerable from './erc721-enumerable';
+import * as erc721WithBalance from './erc721-with-balance';
 import * as erc721WithMultiplier from './erc721-with-multiplier';
 import * as erc721WithTokenId from './erc721-with-tokenid';
 import * as hoprUniLpFarm from './hopr-uni-lp-farm';
@@ -235,6 +236,7 @@ const strategies = {
   'maker-ds-chief': makerDsChief,
   erc721,
   'erc721-enumerable': erc721Enumerable,
+  'erc721-with-balance': erc721WithBalance,
   'erc721-with-multiplier': erc721WithMultiplier,
   'erc721-with-tokenid': erc721WithTokenId,
   'erc721-multi-registry': erc721MultiRegistry,