From 006c686c1860c078a22c83061d7d493da9608d8b Mon Sep 17 00:00:00 2001
From: Jaco Greeff <jacogr@gmail.com>
Date: Tue, 17 Dec 2019 15:33:45 +0100
Subject: [PATCH] Fix linked maps with optional entries (#1676)

* Fix linked maps with optional entries

* Revert entries() change for linked maps
---
 package.json                      |  2 +-
 packages/api/src/base/Decorate.ts | 20 +++++++++++++-------
 yarn.lock                         |  8 ++++----
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/package.json b/package.json
index 9bfd24dc88..cdaec11243 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
     "@babel/core": "^7.7.5",
     "@babel/register": "^7.7.4",
     "@babel/runtime": "^7.7.6",
-    "@polkadot/dev": "^0.32.0-beta.19",
+    "@polkadot/dev": "^0.32.13",
     "@polkadot/ts": "^0.1.88"
   }
 }
diff --git a/packages/api/src/base/Decorate.ts b/packages/api/src/base/Decorate.ts
index 5a0c1301f1..e7c876eeaa 100644
--- a/packages/api/src/base/Decorate.ts
+++ b/packages/api/src/base/Decorate.ts
@@ -5,7 +5,7 @@
 import { Constants, Storage } from '@polkadot/metadata/Decorated/types';
 import { RpcInterface } from '@polkadot/rpc-core/jsonrpc.types';
 import { Call, Hash, RuntimeVersion } from '@polkadot/types/interfaces';
-import { AnyFunction, CallFunction, Codec, CodecArg as Arg, ModulesWithCalls, Registry } from '@polkadot/types/types';
+import { AnyFunction, CallFunction, Codec, CodecArg as Arg, ITuple, ModulesWithCalls, Registry } from '@polkadot/types/types';
 import { SubmittableExtrinsic } from '../submittable/types';
 import {
   ApiInterfaceRx, ApiOptions, ApiTypes,
@@ -20,7 +20,7 @@ import { map, switchMap } from 'rxjs/operators';
 import decorateDerive, { ExactDerive } from '@polkadot/api-derive';
 import RpcCore from '@polkadot/rpc-core';
 import { WsProvider } from '@polkadot/rpc-provider';
-import { Metadata, Null, TypeRegistry, u64, Vec } from '@polkadot/types';
+import { Metadata, Null, Option, TypeRegistry, u64, Vec } from '@polkadot/types';
 import Linkage, { LinkageResult } from '@polkadot/types/codec/Linkage';
 import { DEFAULT_VERSION as EXTRINSIC_DEFAULT_VERSION } from '@polkadot/types/primitive/Extrinsic/constants';
 import StorageKey, { StorageEntry } from '@polkadot/types/primitive/StorageKey';
@@ -38,6 +38,8 @@ interface MetaDecoration {
   toJSON: () => any;
 }
 
+type LinkageData = ITuple<[Codec, Linkage<Codec>]>;
+
 export default abstract class Decorate<ApiType extends ApiTypes> extends Events {
   public readonly registry: Registry;
 
@@ -298,7 +300,7 @@ export default abstract class Decorate<ApiType extends ApiTypes> extends Events
   }
 
   private decorateStorageLinked<ApiType extends ApiTypes> (creator: StorageEntry, decorateMethod: DecorateMethod<ApiType>): ReturnType<DecorateMethod<ApiType>> {
-    const result: Map<Codec, [Codec, Linkage<Codec>]> = new Map();
+    const result: Map<Codec, ITuple<[Codec, Linkage<Codec>]> | null> = new Map();
     let subject: BehaviorSubject<LinkageResult>;
     let head: Codec | null = null;
 
@@ -306,13 +308,17 @@ export default abstract class Decorate<ApiType extends ApiTypes> extends Events
     // entries can be re-linked in the middle of a list, we subscribe here to make
     // sure we catch any updates, no matter the list position
     const getNext = (key: Codec): Observable<LinkageResult> =>
-      this._rpcCore.state.subscribeStorage<[[Codec, Linkage<Codec>]]>([[creator, key]]).pipe(
-        switchMap(([data]: [[Codec, Linkage<Codec>]]): Observable<LinkageResult> => {
+      this._rpcCore.state.subscribeStorage<[LinkageData | Option<LinkageData>]>([[creator, key]]).pipe(
+        switchMap(([_data]: [LinkageData | Option<LinkageData>]): Observable<LinkageResult> => {
+          const data = creator.meta.modifier.isOptional
+            ? (_data as Option<LinkageData>).unwrapOr(null)
+            : _data as LinkageData;
+
           result.set(key, data);
 
           // iterate from this key to the linkages, constructing entries for all
           // those found and available
-          if (data[1].next.isSome) {
+          if (data && data[1].next.isSome) {
             return getNext(data[1].next.unwrap());
           }
 
@@ -334,7 +340,7 @@ export default abstract class Decorate<ApiType extends ApiTypes> extends Events
             keys.push(nextKey);
             vals.push(item);
 
-            nextKey = linkage.next && linkage.next.unwrapOr(null);
+            nextKey = linkage.next?.unwrapOr(null);
           }
 
           const nextResult = vals.length
diff --git a/yarn.lock b/yarn.lock
index e4e8149b40..c70add6bfe 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1832,10 +1832,10 @@
   dependencies:
     "@types/node" ">= 8"
 
-"@polkadot/dev@^0.32.0-beta.19":
-  version "0.32.0-beta.19"
-  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.32.0-beta.19.tgz#9f4e9a78a559f4e050842a6a06365d16d7003188"
-  integrity sha512-Ozftw1CLtu/K4c8039/b2qBvvrLDSA8GsZi9MdwN0t17AuGmkWruiZ8apd3M4Cqfc7q7NbiwGfOvCdk/7tpTfw==
+"@polkadot/dev@^0.32.13":
+  version "0.32.13"
+  resolved "https://registry.npmjs.org/@polkadot/dev/-/dev-0.32.13.tgz#b6f60f48539bd533e84cec7949d340fb66b6f183"
+  integrity sha512-huHQmHiPxi735lVdnjrNggVnX6FpGz2sikoQzw80HwMN90/nX3QiQeE44CQA4IhHMxQtFAQWfKBDfExFTHJjVQ==
   dependencies:
     "@babel/cli" "^7.7.5"
     "@babel/core" "^7.7.5"