Flatten more combineLatest into queryMulti (#1528)

packages/api-derive/src/session/info.ts

@@ -5,7 +5,7 @@
 import { BlockNumber, EraIndex, SessionIndex } from '@polkadot/types/interfaces';
 import { DerivedSessionInfo } from '../types';
 
-import { Observable, combineLatest, of } from 'rxjs';
+import { Observable, combineLatest } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
 import { Option, u64, createType } from '@polkadot/types';
@@ -17,9 +17,9 @@ type Result94Session = [SessionIndex, Option<BlockNumber>, BlockNumber, BlockNum
 type Result94 = [BlockNumber, Result94Session];
 
 type ResultIndex = [SessionIndex, EraIndex];
-type ResultSlots = [u64, u64, u64];
+type ResultSlots = [u64, u64, u64, SessionIndex, EraIndex];
 type ResultType = [boolean, boolean, u64, SessionIndex];
-type Result = [ResultType, ResultSlots, ResultIndex];
+type Result = [ResultType, ResultSlots];
 
 // internal helper to just split the logic - take all inputs, do the calculations and combine
 function createDerived94 ([bestNumber, [currentIndex, _lastLengthChange, sessionLength, lastEraLengthChange, sessionsPerEra]]: Result94): DerivedSessionInfo {
@@ -49,7 +49,7 @@ function createDerived94 ([bestNumber, [currentIndex, _lastLengthChange, session
   };
 }
 
-function createDerivedLatest ([[hasBabe, isGenesisSlot, epochDuration, sessionsPerEra], [currentSlot, epochIndex, epochOrGenesisStartSlot], [currentIndex, currentEra]]: Result): DerivedSessionInfo {
+function createDerivedLatest ([[hasBabe, isGenesisSlot, epochDuration, sessionsPerEra], [currentSlot, epochIndex, epochOrGenesisStartSlot, currentIndex, currentEra]]: Result): DerivedSessionInfo {
   const epochStartSlot = isGenesisSlot
     ? epochIndex
       .mul(epochDuration)
@@ -91,33 +91,37 @@ function info94 (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
   );
 }
 
-function infoLatest (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
-  const hasBabe = !!api.consts.babe;
-
-  return combineLatest([
-    of([
-      hasBabe,
-      hasBabe && !!api.query.babe.genesisSlot,
-      hasBabe
-        ? api.consts.babe.epochDuration as u64
-        : createType('u64', 1),
-      api.consts.staking.sessionsPerEra as SessionIndex
-    ] as ResultType),
-    hasBabe
-      ? api.queryMulti<ResultSlots>([
-        api.query.babe.currentSlot,
-        api.query.babe.epochIndex,
-        api.query.babe.genesisSlot
-          ? api.query.babe.genesisSlot
-          : api.query.babe.epochStartSlot
-      ])
-      : of([createType('u64', 1), createType('u64', 1), createType('u64', 1)] as ResultSlots),
-    api.queryMulti<ResultIndex>([
-      api.query.session.currentIndex,
-      api.query.staking.currentEra
-    ])
+function infoLatestAura (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
+  return api.queryMulti<ResultIndex>([
+    api.query.session.currentIndex,
+    api.query.staking.currentEra
   ]).pipe(
-    map(createDerivedLatest),
+    map(([currentIndex, currentEra]): DerivedSessionInfo =>
+      createDerivedLatest([
+        [false, false, createType('u64', 1), api.consts.staking.sessionsPerEra as SessionIndex],
+        [createType('u64', 1), createType('u64', 1), createType('u64', 1), currentIndex, currentEra]
+      ])
+    ),
+    drr()
+  );
+}
+
+function infoLatestBabe (api: ApiInterfaceRx): Observable<DerivedSessionInfo> {
+  return api.queryMulti<ResultSlots>([
+    api.query.babe.currentSlot,
+    api.query.babe.epochIndex,
+    api.query.babe.genesisSlot
+      ? api.query.babe.genesisSlot
+      : api.query.babe.epochStartSlot,
+    api.query.session.currentIndex,
+    api.query.staking.currentEra
+  ]).pipe(
+    map((slots: ResultSlots): DerivedSessionInfo =>
+      createDerivedLatest([
+        [true, !!api.query.babe.genesisSlot, api.consts.babe.epochDuration as u64, api.consts.staking.sessionsPerEra as SessionIndex],
+        slots
+      ])
+    ),
     drr()
   );
 }
@@ -132,6 +136,8 @@ export function info (api: ApiInterfaceRx): () => Observable<DerivedSessionInfo>
     // https://github.com/paritytech/substrate/commit/dbf322620948935d2bbae214504e6c668c3073ed#diff-c29f42d6b931fa93ba038dbbbfec3055
     return api.query.session.lastLengthChange
       ? info94(api) // 1.x
-      : infoLatest(api); // 2.x
+      : api.consts.babe
+        ? infoLatestBabe(api) // 2.x with Babe
+        : infoLatestAura(api); // 2.x with Aura (not all info there)
   };
 }

packages/api-derive/src/session/sessionProgress.ts

@@ -2,7 +2,8 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import BN from 'bn.js';
+import { BlockNumber } from '@polkadot/types/interfaces';
+
 import { Observable } from 'rxjs';
 import { map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
@@ -10,10 +11,10 @@ import { ApiInterfaceRx } from '@polkadot/api/types';
 import { drr } from '../util/drr';
 import { info } from './info';
 
-export function sessionProgress (api: ApiInterfaceRx): () => Observable<BN> {
-  return (): Observable<BN> =>
+export function sessionProgress (api: ApiInterfaceRx): () => Observable<BlockNumber> {
+  return (): Observable<BlockNumber> =>
     info(api)().pipe(
-      map(({ sessionProgress }): BN => sessionProgress),
+      map(({ sessionProgress }): BlockNumber => sessionProgress),
       drr()
     );
 }

packages/api-derive/src/staking/info.ts

@@ -22,9 +22,7 @@ import { eraLength } from '../session/eraLength';
 import { recentlyOffline } from './recentlyOffline';
 import { drr } from '../util/drr';
 
-type MultiResult = [Option<Keys>, [
-  Option<AccountId> | Vec<[AccountId, Keys] & Codec>, Option<StakingLedger>, [AccountId[]], RewardDestination, Exposure, [ValidatorPrefs]
-]];
+type MultiResult = [Option<AccountId> | Vec<[AccountId, Keys] & Codec>, Option<StakingLedger>, [AccountId[]], RewardDestination, Exposure, [ValidatorPrefs], Option<Keys>?];
 
 // groups the supplied chunks by era, i.e. { [era]: BN(total of values) }
 function groupByEra (list: UnlockChunk[]): Record<string, BN> {
@@ -114,23 +112,25 @@ function unwrapSessionIds (stashId: AccountId, queuedKeys: Option<AccountId> | V
 }
 
 function retrieveMulti (api: ApiInterfaceRx, stashId: AccountId, controllerId: AccountId): Observable<MultiResult> {
-  return combineLatest([
-    // TODO We really want this as part of the multi, however can only do that
-    // once we drop substrate 1.x support (nulti requires values for all)
-    api.query.session.nextKeys
-      ? api.query.session.nextKeys<Option<Keys>>(api.consts.session.dedupKeyPrefix, stashId)
-      : of(createType('Option<Keys>', null)),
-    api.queryMulti([
-      api.query.session.queuedKeys
-        ? [api.query.session.queuedKeys]
-        : [api.query.session.nextKeyFor, controllerId],
-      [api.query.staking.ledger, controllerId],
-      [api.query.staking.nominators, stashId],
-      [api.query.staking.payee, stashId],
-      [api.query.staking.stakers, stashId],
-      [api.query.staking.validators, stashId]
-    ])
-  ]) as Observable<MultiResult>;
+  // A bit horrible, since we push below to forge everything into 1 query - we do this we we end up with one
+  // query to retrieve everything
+  const queries: Array<any> = [
+    api.query.session.queuedKeys
+      ? [api.query.session.queuedKeys]
+      : [api.query.session.nextKeyFor, controllerId],
+    [api.query.staking.ledger, controllerId],
+    [api.query.staking.nominators, stashId],
+    [api.query.staking.payee, stashId],
+    [api.query.staking.stakers, stashId],
+    [api.query.staking.validators, stashId]
+  ];
+
+  //
+  if (api.query.session.nextKeys) {
+    queries.push([api.query.session.nextKeys, [api.consts.session.dedupKeyPrefix, stashId]]);
+  }
+
+  return api.queryMulti(queries) as Observable<MultiResult>;
 }
 
 function retrieveInfo (api: ApiInterfaceRx, accountId: AccountId, stashId: AccountId, controllerId: AccountId): Observable<DerivedStaking> {
@@ -140,7 +140,7 @@ function retrieveInfo (api: ApiInterfaceRx, accountId: AccountId, stashId: Accou
     recentlyOffline(api)(),
     retrieveMulti(api, stashId, controllerId)
   ]).pipe(
-    map(([eraLength, bestNumber, recentlyOffline, [nextKeys, [queuedKeys, _stakingLedger, [nominators], rewardDestination, stakers, [validatorPrefs]]]]): DerivedStaking => {
+    map(([eraLength, bestNumber, recentlyOffline, [queuedKeys, _stakingLedger, [nominators], rewardDestination, stakers, [validatorPrefs], nextKeys = createType('Option<Keys>', null)]]): DerivedStaking => {
       const stakingLedger = _stakingLedger.unwrapOr(undefined);
 
       return {