add function for plurality tally (#294)

* add function for plurality tally * test: Add tests for plurality vote and change the output * Remove TODO * Get all votes then sum support * Fix bignumber sort * fix tests Co-authored-by: rafinskipg <[email protected]> Co-authored-by: Adam Goth <[email protected]>
makerdao · Oct 12, 2021 · fd9e662 · fd9e662
1 parent 24a83be
commit fd9e662
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diff --git a/packages/dai-plugin-governance/src/GovPollingService.js b/packages/dai-plugin-governance/src/GovPollingService.js
@@ -1,4 +1,5 @@
 import { PrivateService } from '@makerdao/services-core';
+import BigNumber from 'bignumber.js';
 import { POLLING, BATCH_POLLING } from './utils/constants';
 import { MKR } from './utils/constants';
 import { fromBuffer, toBuffer, paddedArray } from './utils/helpers';
@@ -310,6 +311,60 @@ export default class GovPollingService extends PrivateService {
     return votes;
   }
 
+  async getTallyPlurality(pollId) {
+    const poll = await this._getPoll(pollId);
+    if (!poll) return null;
+
+    const endUnix = Math.floor(poll.endDate / 1000);
+    const currentVotes = await this.get(
+      'govQueryApi'
+    ).getMkrSupportRankedChoice(pollId, endUnix);
+
+    const numVoters = currentVotes.length;
+
+    const resultsObject = currentVotes.reduce((acc, cur) => {
+      if (acc[cur.optionIdRaw]) {
+        acc[cur.optionIdRaw] = new BigNumber(acc[cur.optionIdRaw]).plus(
+          cur.mkrSupport
+        );
+      } else {
+        acc[cur.optionIdRaw] = new BigNumber(cur.mkrSupport);
+      }
+      return acc;
+    }, {});
+
+    const summedSupport = Object.keys(resultsObject).map(option => ({
+      optionId: option,
+      mkrSupport: resultsObject[option]
+    }));
+
+    const sorted = summedSupport.sort((prev, next) =>
+      prev.mkrSupport.gt(next.mkrSupport) ? -1 : 1
+    );
+
+    const winner = (sorted[0] ? sorted[0].optionId : 0).toString();
+
+    const totalMkrParticipation = summedSupport.reduce(
+      (acc, cur) => new BigNumber(cur.mkrSupport || 0).plus(acc),
+      new BigNumber(0)
+    );
+
+    const options = summedSupport.reduce((a, v) => {
+      a[v.optionId] = {
+        mkrSupport: new BigNumber(v.mkrSupport || 0),
+        winner: v.optionId === winner
+      };
+      return a;
+    }, {});
+
+    return {
+      winner,
+      totalMkrParticipation,
+      numVoters,
+      options
+    };
+  }
+
   async getTallyRankedChoiceIrv(pollId) {
     const poll = await this._getPoll(pollId);
     if (!poll) return {};

diff --git a/packages/dai-plugin-governance/test/GovPollingService.test.js b/packages/dai-plugin-governance/test/GovPollingService.test.js
@@ -26,7 +26,9 @@ import {
   dummyBallotDontMoveToEliminated,
   dummyBallotDontMoveToEliminatedExpect,
   dummyBallotStopWhenOneRemains,
-  dummyBallotStopWhenOneRemainsExpect
+  dummyBallotStopWhenOneRemainsExpect,
+  dummyMkrGetMkrSupportRCForPluralityData,
+  dummyMkrGetMkrSupportRCForPluralityDataAdjusted
 } from './fixtures';
 import { MKR } from '../src/utils/constants';
 
@@ -328,6 +330,66 @@ test('should correctly decode ranked choice options from event logs', () => {
   expect(decodedOptions).toEqual(expectedOptions);
 });
 
+test('plurality tally', async () => {
+  govQueryApiService.getMkrSupportRankedChoice = jest.fn(
+    () => dummyMkrGetMkrSupportRCForPluralityData
+  );
+  govPollingService._getPoll = jest.fn(() => ({
+    endDate: 123
+  }));
+  const tally = await govPollingService.getTallyPlurality();
+
+  const expectedResult = {
+    winner: '1',
+    totalMkrParticipation: '809',
+    numVoters: 5,
+    options: {
+      '0': {
+        mkrSupport: '109',
+        winner: false
+      },
+      '1': {
+        mkrSupport: '700',
+        winner: true
+      }
+    }
+  };
+
+  expect(JSON.parse(JSON.stringify(tally))).toEqual(expectedResult);
+});
+
+test('plurality tally with adjusted votes', async () => {
+  govQueryApiService.getMkrSupportRankedChoice = jest.fn(
+    () => dummyMkrGetMkrSupportRCForPluralityDataAdjusted
+  );
+  govPollingService._getPoll = jest.fn(() => ({
+    endDate: 123
+  }));
+  const tally = await govPollingService.getTallyPlurality();
+
+  const expectedResult = {
+    winner: '2',
+    totalMkrParticipation: '2041',
+    numVoters: 7,
+    options: {
+      '0': {
+        mkrSupport: '109',
+        winner: false
+      },
+      '1': {
+        mkrSupport: '700',
+        winner: false
+      },
+      '2': {
+        mkrSupport: '1232',
+        winner: true
+      }
+    }
+  };
+
+  expect(JSON.parse(JSON.stringify(tally))).toEqual(expectedResult);
+});
+
 // IRV algo tests
 
 test('ranked choice tally with majority', async () => {

diff --git a/packages/dai-plugin-governance/test/fixtures.js b/packages/dai-plugin-governance/test/fixtures.js
@@ -16,6 +16,59 @@ export const dummyMkrSupportData = [
   }
 ];
 
+export const dummyMkrGetMkrSupportRCForPluralityData = [
+  {
+    optionIdRaw: '1',
+    mkrSupport: '40'
+  },
+  {
+    optionIdRaw: '1',
+    mkrSupport: '60'
+  },
+  {
+    optionIdRaw: '0',
+    mkrSupport: '77'
+  },
+  {
+    optionIdRaw: '0',
+    mkrSupport: '32'
+  },
+  {
+    optionIdRaw: '1',
+    mkrSupport: '600'
+  }
+];
+export const dummyMkrGetMkrSupportRCForPluralityDataAdjusted = [
+  {
+    optionIdRaw: '1',
+    mkrSupport: '40'
+  },
+  {
+    optionIdRaw: '1',
+    mkrSupport: '60'
+  },
+  {
+    optionIdRaw: '0',
+    mkrSupport: '77'
+  },
+  {
+    optionIdRaw: '0',
+    mkrSupport: '32'
+  },
+  {
+    optionIdRaw: '1',
+    mkrSupport: '600'
+  },
+  {
+    optionIdRaw: '2',
+    mkrSupport: '32'
+  },
+  {
+    optionIdRaw: '2',
+    mkrSupport: '1200'
+  }
+];
+
 export const dummyAllPollsData = [
   {
     creator: '0xeda95d1bdb60f901986f43459151b6d1c734b8a2',