fix: incorporate era length which may be less than a day for some chains while calc a validators APY

packages/extension-polkagate/src/hooks/useBlockInterval.ts

@@ -1,6 +1,5 @@
 // Copyright 2019-2024 @polkadot/extension-polkagate authors & contributors
 // SPDX-License-Identifier: Apache-2.0
-// @ts-nocheck
 
 import type { ApiPromise } from '@polkadot/api';
 
@@ -17,29 +16,34 @@ export const A_DAY = new BN(24 * 60 * 60 * 1000);
 const THRESHOLD = BN_THOUSAND.div(BN_TWO);
 const DEFAULT_TIME = new BN(6_000);
 
-function calcInterval(api: ApiPromise): BN {
-    return bnMin(A_DAY, (
-        // Babe, e.g. Relay chains (Substrate defaults)
-        api.consts.babe?.expectedBlockTime ||
-        // POW, eg. Kulupu
-        api.consts.difficulty?.targetBlockTime ||
-        // Subspace
-        api.consts.subspace?.expectedBlockTime || (
-            // Check against threshold to determine value validity
-            api.consts.timestamp?.minimumPeriod.gte(THRESHOLD)
-                // Default minimum period config
-                ? api.consts.timestamp.minimumPeriod.mul(BN_TWO)
-                : api.query.parachainSystem
-                    // default guess for a parachain
-                    ? DEFAULT_TIME.mul(BN_TWO)
-                    // default guess for others
-                    : DEFAULT_TIME
-        )
-    ));
+export function calcInterval (api: ApiPromise | undefined): BN {
+  if (!api) {
+    return DEFAULT_TIME;
+  }
+
+  return bnMin(A_DAY, (
+    // Babe, e.g. Relay chains (Substrate defaults)
+    api.consts['babe']?.['expectedBlockTime'] as unknown as BN ||
+      // POW, eg. Kulupu
+      api.consts['difficulty']?.['targetBlockTime'] as unknown as BN ||
+    // Subspace
+      // Subspace
+      api.consts['subspace']?.['expectedBlockTime'] || (
+    // Check against threshold to determine value validity
+      (api.consts['timestamp']?.['minimumPeriod'] as unknown as BN).gte(THRESHOLD)
+      // Default minimum period config
+        ? (api.consts['timestamp']['minimumPeriod'] as unknown as BN).mul(BN_TWO)
+        : api.query['parachainSystem']
+        // default guess for a parachain
+          ? DEFAULT_TIME.mul(BN_TWO)
+        // default guess for others
+          : DEFAULT_TIME
+    )
+  ));
 }
 
-export default function useBlockInterval(address: string | undefined): BN | undefined {
-    const api = useApi(address);
+export default function useBlockInterval (address: string | undefined): BN | undefined {
+  const api = useApi(address);
 
-    return useMemo(() => api && calcInterval(api), [api]);
+  return useMemo(() => api && calcInterval(api), [api]);
 }

packages/extension-polkagate/src/hooks/useValidatorApy.ts

@@ -3,38 +3,46 @@
 
 import type { ApiPromise } from '@polkadot/api';
 import type { Option, u128 } from '@polkadot/types';
-//@ts-ignore
+// @ts-ignore
 import type { PalletStakingActiveEraInfo, PalletStakingEraRewardPoints, PalletStakingValidatorPrefs, SpStakingPagedExposureMetadata } from '@polkadot/types/lookup';
 
 import { useCallback, useEffect, useState } from 'react';
 
-import { BN, BN_HUNDRED, BN_ZERO } from '@polkadot/util';
+import { BN, BN_ZERO } from '@polkadot/util';
+
+import { calcInterval } from './useBlockInterval';
 
 interface ValidatorEraInfo {
-  netReward: BN;
+  netReward: number;
   total: BN;
 }
 
 export default function useValidatorApy (api: ApiPromise | undefined, validatorAddress: string, isElected?: boolean): string | undefined | null {
   const [apy, setApy] = useState<string | null>();
+  const blockInterval = calcInterval(api);
+  const blockIntervalInSec = blockInterval.toNumber() / 1000;
 
   const calculateValidatorAPY = useCallback(async (validatorAddress: string) => {
     if (!api) {
       return;
     }
 
-    // Define the number of past eras you want to check (e.g., last 10 eras)
-    const eraDepth = 10;
     const decimal = new BN(10 ** api.registry.chainDecimals[0]);
-    let totalRewards = BN_ZERO;
+    let totalRewards = 0;
     let totalPoints = BN_ZERO;
     let validatorPoints = BN_ZERO;
     let totalStaked = BN_ZERO;
     const validatorEraInfo: ValidatorEraInfo[] = [];
 
+    const { eraLength } = await api.derive.session.progress();
+
     const currentEra = ((await api.query['staking']['activeEra']()) as Option<PalletStakingActiveEraInfo>).unwrap().index.toNumber();
     const { commission } = await api.query['staking']['validators'](validatorAddress) as PalletStakingValidatorPrefs;
 
+    const eraLengthInHrs = eraLength.toNumber() * blockIntervalInSec / 3600; // 3600 = 1hr in seconds
+    const eraPerDay = 24 / eraLengthInHrs;
+    const eraDepth = 10 * eraPerDay; // eras to calculate
+
     // Loop over the past eras to calculate rewards for the validator
     for (let eraIndex = currentEra - eraDepth; eraIndex <= currentEra; eraIndex++) {
       let netReward;
@@ -61,7 +69,7 @@ export default function useValidatorApy (api: ApiPromise | undefined, validatorA
         totalPoints = totalPoints.add(eraPoints.total);
         const _eraReward = eraReward.unwrap();
 
-        netReward = _eraReward.mul(validatorPoints).div(totalPoints).muln(100 - (commission.toNumber() / 1e7)).div(BN_HUNDRED);
+        netReward = _eraReward.toNumber() * (validatorPoints.toNumber() / totalPoints.toNumber()) * (100 - (commission.toNumber() / 1e7)) / 100;
       } else {
         continue;
       }
@@ -92,19 +100,16 @@ export default function useValidatorApy (api: ApiPromise | undefined, validatorA
     }
 
     validatorEraInfo.forEach(({ netReward, total }) => {
-      totalRewards = totalRewards.add(netReward);
+      totalRewards += netReward;
       totalStaked = totalStaked.add(total);
     });
 
     const actualDepth = validatorEraInfo.length;
 
     totalStaked = totalStaked.div(decimal).divn(actualDepth);
 
-    const dailyReward = totalRewards.div(decimal).divn(actualDepth);
-
-    // Calculate daily return as a fraction of the staked amount
-    const dailyReturn = dailyReward.toNumber() / totalStaked.toNumber();
-
+    const dailyReward = (totalRewards / decimal.toNumber() / actualDepth) * eraPerDay;
+    const dailyReturn = dailyReward / totalStaked.toNumber();
     const APY = (dailyReturn * 365 * 100).toFixed(2);
 
     if (!isFinite(+APY) || isNaN(+APY)) {

packages/extension/public/locales/en/translation.json

@@ -1467,4 +1467,4 @@
   "Menu options": "",
   "PolkaGate logo": "",
   "Total balance": ""
-}
+}