subscribeNewHeads (#1338)

* subscribeNewHeads

* Update CHANGELOG

* Rebuild interfaces

* Sort interfaces, really expose plural

* Fix mocks

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().pipe(
+    api.rpc.chain.subscribeNewHeads().pipe(
       map((header): BlockNumber => header.number.unwrap()),
       drr()
     );

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

@@ -8,7 +8,7 @@ import { ApiInterfaceRx } from '@polkadot/api/types';
 
 import { HeaderExtended } from '../type';
 import { drr } from '../util/drr';
-import { HeaderAndValidators } from './subscribeNewHead';
+import { HeaderAndValidators } from './subscribeNewHeads';
 
 /**
  * @name bestNumberFinalized

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

@@ -6,4 +6,4 @@ export * from './bestNumber';
 export * from './bestNumberFinalized';
 export * from './bestNumberLag';
 export * from './getHeader';
-export * from './subscribeNewHead';
+export * from './subscribeNewHeads';

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

@@ -14,21 +14,21 @@ import { drr } from '../util/drr';
 export type HeaderAndValidators = [Header, AccountId[]];
 
 /**
- * @name subscribeNewHead
+ * @name subscribeNewHeads
  * @returns An array containing the block header and the block author
  * @description An observable of the current block header and it's author
  * @example
  * <BR>
  *
  * ```javascript
- * api.derive.chain.subscribeNewHead(({ author, blockNumber }) => {
+ * api.derive.chain.subscribeNewHeads(({ author, blockNumber }) => {
  *   console.log(`block #${blockNumber} was authored by ${author}`);
  * });
  * ```
  */
-export function subscribeNewHead (api: ApiInterfaceRx): () => Observable<HeaderExtended> {
+export function subscribeNewHeads (api: ApiInterfaceRx): () => Observable<HeaderExtended> {
   return (): Observable<HeaderExtended> =>
-    api.rpc.chain.subscribeNewHead().pipe(
+    api.rpc.chain.subscribeNewHeads().pipe(
       switchMap((header: Header): Observable<HeaderAndValidators> =>
         (combineLatest([
           of(header),