Parachain light clients (#8050)

* feat: Added parachain light clients

* fix: Add resolve json compiler option

* chore: Fix lints

* refactor: Better organized light client specs

* chore: Added sort lint and some doc strings

packages/apps-config/src/endpoints/productionRelayKusama.ts

@@ -130,7 +130,8 @@ export const prodParasKusama: EndpointOption[] = [
     providers: {
       GMorDieDAO: 'wss://kusama.gmordie.com',
       'bLd Nodes': 'wss://ws.gm.bldnodes.org',
-      TerraBioDAO: 'wss://ws-node-gm.terrabiodao.org'
+      TerraBioDAO: 'wss://ws-node-gm.terrabiodao.org',
+      'light client': 'light://substrate-connect/kusama/gm'
     }
   },
   {
@@ -158,7 +159,8 @@ export const prodParasKusama: EndpointOption[] = [
     paraId: 2125,
     text: 'InvArch Tinkernet',
     providers: {
-      'InvArch Team': 'wss://tinker.invarch.network'
+      'InvArch Team': 'wss://tinker.invarch.network',
+      'light client': 'light://substrate-connect/kusama/tinkernet'
     }
   },
   {

packages/react-api/src/Api.tsx

@@ -26,6 +26,7 @@ import { formatBalance, isNumber, isTestChain, objectSpread, stringify } from '@
 import { defaults as addressDefaults } from '@polkadot/util-crypto/address/defaults';
 
 import ApiContext from './ApiContext';
+import { lightSpecs } from './light-client-specs';
 import registry from './typeRegistry';
 import { decodeUrlTypes } from './urlTypes';
 
@@ -234,19 +235,29 @@ async function loadOnReady (api: ApiPromise, endpoint: LinkOption | null, inject
   };
 }
 
-function getWellKnownChain (chain = 'polkadot') {
-  switch (chain) {
-    case 'kusama':
-      return WellKnownChain.ksmcc3;
-    case 'polkadot':
-      return WellKnownChain.polkadot;
-    case 'rococo':
-      return WellKnownChain.rococo_v2_2;
-    case 'westend':
-      return WellKnownChain.westend2;
-    default:
-      throw new Error(`Unable to construct light chain ${chain}`);
-  }
+function getLightProvider (chain = 'polkadot') {
+  const [relayArg, paraArg] = chain.split('/');
+
+  const wellKnown = () => {
+    switch (relayArg) {
+      case 'kusama':
+        return WellKnownChain.ksmcc3;
+      case 'polkadot':
+        return WellKnownChain.polkadot;
+      case 'rococo':
+        return WellKnownChain.rococo_v2_2;
+      case 'westend':
+        return WellKnownChain.westend2;
+      default:
+        throw new Error(`Unable to construct light chain ${chain}`);
+    }
+  };
+
+  const relay = new ScProvider(wellKnown());
+
+  return paraArg && lightSpecs[paraArg]
+    ? new ScProvider(JSON.stringify(lightSpecs[paraArg]), relay)
+    : relay;
 }
 
 async function createApi (apiUrl: string, signer: ApiSigner, onError: (error: unknown) => void): Promise<Record<string, Record<string, string>>> {
@@ -256,7 +267,7 @@ async function createApi (apiUrl: string, signer: ApiSigner, onError: (error: un
   try {
     const providers = [0].map((): ProviderInterface =>
       isLight
-        ? new ScProvider(getWellKnownChain(apiUrl.replace('light://substrate-connect/', '')))
+        ? getLightProvider(apiUrl.replace('light://substrate-connect/', ''))
         : new WsProvider(apiUrl)
     );
 

packages/react-api/src/light-client-specs/index.ts

@@ -0,0 +1,15 @@
+// Copyright 2017-2022 @polkadot/react-api authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/* eslint sort-keys: ["error", "asc", { caseSensitive: false }] */
+
+import gmSpec from './gm.json';
+import tinkernetSpec from './tinkernet.json';
+
+// Add your imported spec here in alphabetical order.
+// The key here reflects the URL of the light client endpoint.
+// e.g. light://substrate-connect/kusama/gm
+export const lightSpecs: Record<string, unknown> = {
+  gm: gmSpec,
+  tinkernet: tinkernetSpec
+};

tsconfig.build.json

@@ -2,7 +2,8 @@
   "extends": "./tsconfig.base.json",
   "compilerOptions": {
     "baseUrl": "./packages",
-    "outDir": "./build"
+    "outDir": "./build",
+    "resolveJsonModule": true,
   },
   "exclude": [
     "build/**/*",