From 59b9eb5867947957304b965349feb07a1e7ee42d Mon Sep 17 00:00:00 2001
From: Ben Kremer <ben@walletconnect.com>
Date: Thu, 17 Mar 2022 16:56:54 +0100
Subject: [PATCH] refactor(dapp-v2): separates `chainData` into own
 context/hook

---
 dapps/react-dapp-v2/src/App.tsx               |  4 +-
 .../src/contexts/ChainDataContext.tsx         | 70 +++++++++++++++++++
 .../src/contexts/JsonRpcContext.tsx           | 42 ++---------
 dapps/react-dapp-v2/src/index.tsx             | 14 ++--
 4 files changed, 87 insertions(+), 43 deletions(-)
 create mode 100644 dapps/react-dapp-v2/src/contexts/ChainDataContext.tsx

diff --git a/dapps/react-dapp-v2/src/App.tsx b/dapps/react-dapp-v2/src/App.tsx
index c6e5c06..e110ce7 100644
--- a/dapps/react-dapp-v2/src/App.tsx
+++ b/dapps/react-dapp-v2/src/App.tsx
@@ -30,6 +30,7 @@ import {
 } from "./components/app";
 import { useWalletConnectClient } from "./contexts/ClientContext";
 import { useJsonRpc } from "./contexts/JsonRpcContext";
+import { useChainData } from "./contexts/ChainDataContext";
 
 export default function App() {
   const [modal, setModal] = useState("");
@@ -55,7 +56,6 @@ export default function App() {
 
   // Use `JsonRpcContext` to provide us with relevant RPC methods and states.
   const {
-    chainData,
     ping,
     ethereumRpc,
     cosmosRpc,
@@ -66,6 +66,8 @@ export default function App() {
     setIsTestnet,
   } = useJsonRpc();
 
+  const { chainData } = useChainData();
+
   // Close the pairing modal after a session is established.
   useEffect(() => {
     if (session && modal === "pairing") {
diff --git a/dapps/react-dapp-v2/src/contexts/ChainDataContext.tsx b/dapps/react-dapp-v2/src/contexts/ChainDataContext.tsx
new file mode 100644
index 0000000..012d64a
--- /dev/null
+++ b/dapps/react-dapp-v2/src/contexts/ChainDataContext.tsx
@@ -0,0 +1,70 @@
+import { apiGetChainNamespace, ChainsMap } from "caip-api";
+import { createContext, ReactNode, useContext, useEffect, useState } from "react";
+import { SolanaChainData } from "../chains/solana";
+
+import { ChainNamespaces, getAllChainNamespaces } from "../helpers";
+
+/**
+ * Types
+ */
+interface IContext {
+  chainData: ChainNamespaces;
+}
+
+/**
+ * Context
+ */
+export const ChainDataContext = createContext<IContext>({} as IContext);
+
+/**
+ * Provider
+ */
+export function ChainDataContextProvider({ children }: { children: ReactNode | ReactNode[] }) {
+  const [chainData, setChainData] = useState<ChainNamespaces>({});
+
+  const loadChainData = async () => {
+    const namespaces = getAllChainNamespaces();
+    const chainData: ChainNamespaces = {};
+    await Promise.all(
+      namespaces.map(async namespace => {
+        let chains: ChainsMap | undefined;
+        try {
+          if (namespace === "solana") {
+            chains = SolanaChainData;
+          } else {
+            chains = await apiGetChainNamespace(namespace);
+          }
+        } catch (e) {
+          // ignore error
+        }
+        if (typeof chains !== "undefined") {
+          chainData[namespace] = chains;
+        }
+      }),
+    );
+
+    setChainData(chainData);
+  };
+
+  useEffect(() => {
+    loadChainData();
+  }, []);
+
+  return (
+    <ChainDataContext.Provider
+      value={{
+        chainData,
+      }}
+    >
+      {children}
+    </ChainDataContext.Provider>
+  );
+}
+
+export function useChainData() {
+  const context = useContext(ChainDataContext);
+  if (context === undefined) {
+    throw new Error("useChainData must be used within a ChainDataContextProvider");
+  }
+  return context;
+}
diff --git a/dapps/react-dapp-v2/src/contexts/JsonRpcContext.tsx b/dapps/react-dapp-v2/src/contexts/JsonRpcContext.tsx
index 19d3cfb..e32d6f4 100644
--- a/dapps/react-dapp-v2/src/contexts/JsonRpcContext.tsx
+++ b/dapps/react-dapp-v2/src/contexts/JsonRpcContext.tsx
@@ -1,29 +1,26 @@
 import { BigNumber, utils } from "ethers";
-import { createContext, ReactNode, useContext, useEffect, useState } from "react";
+import { createContext, ReactNode, useContext, useState } from "react";
 import * as encoding from "@walletconnect/encoding";
+import { TypedDataField } from "@ethersproject/abstract-signer";
 import { formatDirectSignDoc, stringifySignDocValues } from "cosmos-wallet";
 import bs58 from "bs58";
 import { verifyMessageSignature } from "solana-wallet";
+import { clusterApiUrl, Connection, Keypair, SystemProgram, Transaction } from "@solana/web3.js";
 
 import {
-  ChainNamespaces,
   eip712,
   formatTestTransaction,
-  getAllChainNamespaces,
   getLocalStorageTestnetFlag,
   hashPersonalMessage,
   verifySignature,
 } from "../helpers";
 import { useWalletConnectClient } from "./ClientContext";
-import { apiGetChainNamespace, ChainsMap } from "caip-api";
-import { TypedDataField } from "@ethersproject/abstract-signer";
 import {
   DEFAULT_COSMOS_METHODS,
   DEFAULT_EIP155_METHODS,
   DEFAULT_SOLANA_METHODS,
 } from "../constants";
-import { clusterApiUrl, Connection, Keypair, SystemProgram, Transaction } from "@solana/web3.js";
-import { SolanaChainData } from "../chains/solana";
+import { useChainData } from "./ChainDataContext";
 
 /**
  * Types
@@ -59,7 +56,6 @@ interface IContext {
     testSignMessage: TRpcRequestCallback;
     testSignTransaction: TRpcRequestCallback;
   };
-  chainData: ChainNamespaces;
   rpcResult?: IRpcResult | null;
   isRpcRequestPending: boolean;
   isTestnet: boolean;
@@ -77,38 +73,11 @@ export const JsonRpcContext = createContext<IContext>({} as IContext);
 export function JsonRpcContextProvider({ children }: { children: ReactNode | ReactNode[] }) {
   const [pending, setPending] = useState(false);
   const [result, setResult] = useState<IRpcResult | null>();
-  const [chainData, setChainData] = useState<ChainNamespaces>({});
   const [isTestnet, setIsTestnet] = useState(getLocalStorageTestnetFlag());
 
   const { client, session, accounts, balances, solanaPublicKeys } = useWalletConnectClient();
 
-  useEffect(() => {
-    loadChainData();
-  }, []);
-
-  const loadChainData = async () => {
-    const namespaces = getAllChainNamespaces();
-    const chainData: ChainNamespaces = {};
-    await Promise.all(
-      namespaces.map(async namespace => {
-        let chains: ChainsMap | undefined;
-        try {
-          if (namespace === "solana") {
-            chains = SolanaChainData;
-          } else {
-            chains = await apiGetChainNamespace(namespace);
-          }
-        } catch (e) {
-          // ignore error
-        }
-        if (typeof chains !== "undefined") {
-          chainData[namespace] = chains;
-        }
-      }),
-    );
-
-    setChainData(chainData);
-  };
+  const { chainData } = useChainData();
 
   const _createJsonRpcRequestHandler =
     (rpcRequest: (chainId: string, address: string) => Promise<IFormattedRpcResponse>) =>
@@ -568,7 +537,6 @@ export function JsonRpcContextProvider({ children }: { children: ReactNode | Rea
   return (
     <JsonRpcContext.Provider
       value={{
-        chainData,
         ping,
         ethereumRpc,
         cosmosRpc,
diff --git a/dapps/react-dapp-v2/src/index.tsx b/dapps/react-dapp-v2/src/index.tsx
index 564dd79..82f49a7 100644
--- a/dapps/react-dapp-v2/src/index.tsx
+++ b/dapps/react-dapp-v2/src/index.tsx
@@ -1,8 +1,10 @@
 import * as React from "react";
 import * as ReactDOM from "react-dom";
 import { createGlobalStyle } from "styled-components";
+
 import { ClientContextProvider } from "./contexts/ClientContext";
 import { JsonRpcContextProvider } from "./contexts/JsonRpcContext";
+import { ChainDataContextProvider } from "./contexts/ChainDataContext";
 
 import App from "./App";
 import { globalStyle } from "./styles";
@@ -20,11 +22,13 @@ declare global {
 ReactDOM.render(
   <>
     <GlobalStyle />
-    <ClientContextProvider>
-      <JsonRpcContextProvider>
-        <App />
-      </JsonRpcContextProvider>
-    </ClientContextProvider>
+    <ChainDataContextProvider>
+      <ClientContextProvider>
+        <JsonRpcContextProvider>
+          <App />
+        </JsonRpcContextProvider>
+      </ClientContextProvider>
+    </ChainDataContextProvider>
   </>,
   document.getElementById("root"),
 );