Apply SWR to Sourcify contract source code fetching

src/address/Contract.tsx

@@ -1,40 +1,19 @@
 import React from "react";
 import { SyntaxHighlighter, docco } from "../highlight-init";
-import { useContract } from "../sourcify/useSourcify";
-import { useAppConfigContext } from "../useAppConfig";
 
 type ContractProps = {
-  checksummedAddress: string;
-  networkId: number;
-  filename: string;
-  source: any;
+  content: any;
 };
 
-const Contract: React.FC<ContractProps> = ({
-  checksummedAddress,
-  networkId,
-  filename,
-  source,
-}) => {
-  const { sourcifySource } = useAppConfigContext();
-  const content = useContract(
-    checksummedAddress,
-    networkId,
-    filename,
-    source,
-    sourcifySource
-  );
-
-  return (
-    <SyntaxHighlighter
-      className="w-full h-full border font-code text-base"
-      language="solidity"
-      style={docco}
-      showLineNumbers
-    >
-      {content ?? ""}
-    </SyntaxHighlighter>
-  );
-};
+const Contract: React.FC<ContractProps> = ({ content }) => (
+  <SyntaxHighlighter
+    className="w-full h-full border font-code text-base"
+    language="solidity"
+    style={docco}
+    showLineNumbers
+  >
+    {content ?? ""}
+  </SyntaxHighlighter>
+);
 
 export default React.memo(Contract);

src/address/ContractFromRepo.tsx

@@ -0,0 +1,37 @@
+import React from "react";
+import { SyntaxHighlighter, docco } from "../highlight-init";
+import { useContract } from "../sourcify/useSourcify";
+import { useAppConfigContext } from "../useAppConfig";
+
+type ContractFromRepoProps = {
+  checksummedAddress: string;
+  networkId: number;
+  filename: string;
+};
+
+const ContractFromRepo: React.FC<ContractFromRepoProps> = ({
+  checksummedAddress,
+  networkId,
+  filename,
+}) => {
+  const { sourcifySource } = useAppConfigContext();
+  const content = useContract(
+    checksummedAddress,
+    networkId,
+    filename,
+    sourcifySource
+  );
+
+  return (
+    <SyntaxHighlighter
+      className="w-full h-full border font-code text-base"
+      language="solidity"
+      style={docco}
+      showLineNumbers
+    >
+      {content ?? ""}
+    </SyntaxHighlighter>
+  );
+};
+
+export default React.memo(ContractFromRepo);

src/address/Contracts.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useEffect, useContext, Fragment } from "react";
+import React, { useState, useEffect, useContext } from "react";
 import { commify } from "@ethersproject/units";
 import { Menu } from "@headlessui/react";
 import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
@@ -6,6 +6,7 @@ import { faChevronDown } from "@fortawesome/free-solid-svg-icons/faChevronDown";
 import ContentFrame from "../ContentFrame";
 import InfoRow from "../components/InfoRow";
 import Contract from "./Contract";
+import ContractFromRepo from "./ContractFromRepo";
 import { RuntimeContext } from "../useRuntime";
 import { Metadata } from "../sourcify/useSourcify";
 import ExternalLink from "../components/ExternalLink";
@@ -113,12 +114,17 @@ const Contracts: React.FC<ContractsProps> = ({
                 </div>
               </Menu>
               {selected && (
-                <Contract
-                  checksummedAddress={checksummedAddress}
-                  networkId={provider!.network.chainId}
-                  filename={selected}
-                  source={rawMetadata.sources[selected]}
-                />
+                <>
+                  {rawMetadata.sources[selected].content ? (
+                    <Contract content={rawMetadata.sources[selected].content} />
+                  ) : (
+                    <ContractFromRepo
+                      checksummedAddress={checksummedAddress}
+                      networkId={provider!.network.chainId}
+                      filename={selected}
+                    />
+                  )}
+                </>
               )}
             </div>
           </>

src/sourcify/useSourcify.ts

@@ -115,43 +115,33 @@ export const useSourcifyMetadata = (
   return data;
 };
 
+const contractFetcher = async (url: string): Promise<string | null> => {
+  const res = await fetch(url);
+  if (res.ok) {
+    return await res.text();
+  }
+  return null;
+};
+
 export const useContract = (
   checksummedAddress: string,
   networkId: number,
   filename: string,
-  source: any,
   sourcifySource: SourcifySource
 ) => {
-  const [content, setContent] = useState<string>(source.content);
+  const normalizedFilename = filename.replaceAll(/[@:]/g, "_");
+  const url = sourcifySourceFile(
+    checksummedAddress,
+    networkId,
+    normalizedFilename,
+    sourcifySource
+  );
 
-  useEffect(() => {
-    if (source.content) {
-      return;
-    }
-
-    const abortController = new AbortController();
-    const readContent = async () => {
-      const normalizedFilename = filename.replaceAll(/[@:]/g, "_");
-      const url = sourcifySourceFile(
-        checksummedAddress,
-        networkId,
-        normalizedFilename,
-        sourcifySource
-      );
-      const res = await fetch(url, { signal: abortController.signal });
-      if (res.ok) {
-        const _content = await res.text();
-        setContent(_content);
-      }
-    };
-    readContent();
-
-    return () => {
-      abortController.abort();
-    };
-  }, [checksummedAddress, networkId, filename, source.content, sourcifySource]);
-
-  return content;
+  const { data, error } = useSWRImmutable(url, contractFetcher);
+  if (error) {
+    return undefined;
+  }
+  return data;
 };
 
 export const useTransactionDescription = (