Make Block, Header & Digest generic (#1196)

* Make Block, Header & Digest generic

* It lints

* Linting passes, tests passes

packages/api-derive/src/chain/bestNumber.ts

@@ -2,12 +2,11 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { BlockNumber } from '@polkadot/types/interfaces';
+import { BlockNumber, Header } from '@polkadot/types/interfaces';
 
 import { Observable } from 'rxjs';
 import { filter, map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Header } from '@polkadot/types';
 
 import { drr } from '../util/drr';
 
@@ -27,8 +26,8 @@ export function bestNumber (api: ApiInterfaceRx): () => Observable<BlockNumber>
   return (): Observable<BlockNumber> =>
     (api.rpc.chain.subscribeNewHead() as Observable<Header>)
       .pipe(
-        filter((header: Header): boolean => !!header && !!header.blockNumber),
-        map(({ blockNumber }: Header): BlockNumber => blockNumber),
+        filter((header: Header): boolean => !!header && !!header.number),
+        map((header: Header): BlockNumber => header.number.unwrap()),
         drr()
       );
 }

packages/api-derive/src/chain/bestNumberFinalized.ts

@@ -2,12 +2,11 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { BlockNumber } from '@polkadot/types/interfaces';
+import { BlockNumber, Header } from '@polkadot/types/interfaces';
 
 import { Observable } from 'rxjs';
 import { filter, map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Header } from '@polkadot/types';
 
 import { drr } from '../util/drr';
 
@@ -28,8 +27,8 @@ export function bestNumberFinalized (api: ApiInterfaceRx): () => Observable<Bloc
   return (): Observable<BlockNumber> =>
     (api.rpc.chain.subscribeFinalizedHeads() as Observable<Header>)
       .pipe(
-        filter((header: Header): boolean => !!header && !!header.blockNumber),
-        map(({ blockNumber }: Header): BlockNumber => blockNumber),
+        filter((header: Header): boolean => !!header && !!header.number),
+        map((header: Header): BlockNumber => header.number.unwrap()),
         drr()
       );
 }

packages/api-derive/src/chain/getHeader.ts

@@ -2,10 +2,11 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { Header } from '@polkadot/types/interfaces';
+
 import { Observable, combineLatest, of } from 'rxjs';
 import { catchError, map } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { Header } from '@polkadot/types';
 
 import { HeaderExtended } from '../type';
 import { drr } from '../util/drr';
@@ -20,9 +21,9 @@ import { HeaderAndValidators } from './subscribeNewHead';
  * <BR>
  *
  * ```javascript
- * const { author, blockNumber } = await api.derive.chain.getHeader('0x123...456');
+ * const { author, number } = await api.derive.chain.getHeader('0x123...456');
  *
- * console.log(`block #${blockNumber} was authored by ${author}`);
+ * console.log(`block #${number} was authored by ${author}`);
  * ```
  */
 export function getHeader (api: ApiInterfaceRx): (hash: Uint8Array | string) => Observable<HeaderExtended | undefined> {

packages/api-derive/src/chain/subscribeNewHead.ts

@@ -2,10 +2,12 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+import { Header } from '@polkadot/types/interfaces';
+
 import { Observable, combineLatest, of } from 'rxjs';
 import { filter, map, switchMap } from 'rxjs/operators';
 import { ApiInterfaceRx } from '@polkadot/api/types';
-import { AccountId, Header } from '@polkadot/types';
+import { AccountId } from '@polkadot/types';
 
 import { HeaderExtended } from '../type';
 import { drr } from '../util/drr';
@@ -29,7 +31,7 @@ export function subscribeNewHead (api: ApiInterfaceRx): () => Observable<HeaderE
   return (): Observable<HeaderExtended> =>
     (api.rpc.chain.subscribeNewHead() as Observable<Header>)
       .pipe(
-        filter((header: Header): boolean => !!header && !!header.blockNumber),
+        filter((header: Header): boolean => !!header && !!header.number),
         switchMap((header: Header): Observable<HeaderAndValidators> =>
           (combineLatest([
             of(header),