Make api.rpc.*.* typed (#1237)

* Generate correctly

* Fix rpc-core

* Flexible types

* Make types work!

* Lint

* Fix grumble

* Re generate

* Fix lint

* Fix small bugs

* Maybe really fix lint?

* Fix lint again

* Fix lint

* Small ordering & formatting  changes while playing...

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

@@ -24,7 +24,7 @@ import { drr } from '../util/drr';
  */
 export function bestNumber (api: ApiInterfaceRx): () => Observable<BlockNumber> {
   return (): Observable<BlockNumber> =>
-    (api.rpc.chain.subscribeNewHead() as Observable<Header>)
+    api.rpc.chain.subscribeNewHead()
       .pipe(
         filter((header: Header): boolean => !!header && !!header.number),
         map((header: Header): BlockNumber => header.number.unwrap()),

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

@@ -25,7 +25,7 @@ import { drr } from '../util/drr';
  */
 export function bestNumberFinalized (api: ApiInterfaceRx): () => Observable<BlockNumber> {
   return (): Observable<BlockNumber> =>
-    (api.rpc.chain.subscribeFinalizedHeads() as Observable<Header>)
+    api.rpc.chain.subscribeFinalizedHeads()
       .pipe(
         filter((header: Header): boolean => !!header && !!header.number),
         map((header: Header): BlockNumber => header.number.unwrap()),

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

@@ -2,8 +2,6 @@
 // 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';
@@ -30,7 +28,7 @@ export function getHeader (api: ApiInterfaceRx): (hash: Uint8Array | string) =>
   return (hash: Uint8Array | string): Observable<HeaderExtended | undefined> =>
     // tslint:disable-next-line
     (combineLatest([
-      api.rpc.chain.getHeader(hash) as Observable<Header>,
+      api.rpc.chain.getHeader(hash),
       api.query.session
         ? api.query.session.validators.at(hash)
         : of([])