From de690386d6b87bf6ac2889fc446bf8decd485f80 Mon Sep 17 00:00:00 2001
From: Ardis Lu <ardisglu@gmail.com>
Date: Mon, 30 Oct 2023 22:59:45 -0700
Subject: [PATCH] Fetch source code in addition to JSON metadata

---
 index.html | 18 +++++++++++++++++-
 index.js   |  6 +++---
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/index.html b/index.html
index e0fead7..86310ba 100644
--- a/index.html
+++ b/index.html
@@ -220,6 +220,8 @@
       const metadata = decodeCBOR(cbor);
       logOutput(result, '✅ Successfully decoded CBOR metadata.', JSON.stringify(metadata, null, 2));
 
+      // Fetch JSON metadata
+      let json;
       if (metadata.bzzr0 !== undefined) {
         const hex = [...metadata.bzzr0].map(b => b.toString(16).padStart(2, '0')).join('');
         logOutput(result, '❌ Unable to fetch JSON metadata because the smart contract uses a Swarm hash.', `bzzr://${hex}`);
@@ -232,13 +234,27 @@
         const { cidV0, cidV1 } = calculateCID(metadata);
         logOutput(result, '✅ Successfully calculated IPFS CID.', `IPFS CIDv0: ${cidV0}\nIPFS CIDv1: ${cidV1}`);
         try {
-          const json = await fetchJSONMetadata(cidV1, ipfs);
+          json = await fetchCID(cidV1, ipfs).then(r => r.json());
           logOutput(result, '✅ Successfully fetched JSON metadata.', JSON.stringify(json, null, 2));
         }
         catch {
           logOutput(result, '❌ Failed to fetch JSON metadata from IPFS.', `IPFS node: ${ipfs}`);
         }
       }
+
+      // Fetch source code
+      if (json?.sources !== undefined) {
+        for (const [file, source] of Object.entries(json.sources)) {
+          try {
+            const cidV0 = source.urls[1].substring(11);
+            const code = await fetchCID(cidV0, ipfs).then(r => r.text());
+            logOutput(result, `✅ Successfully fetched source code for "${file}" from IPFS.`, code);
+          }
+          catch {
+            logOutput(result, `❌ Failed to fetch source code for "${file}" from IPFS.`, `IPFS node: ${ipfs}`);
+          }
+        }
+      }
     }
 
     document.querySelector('form').addEventListener('submit', async e => {
diff --git a/index.js b/index.js
index 865677b..118ffa8 100644
--- a/index.js
+++ b/index.js
@@ -155,7 +155,7 @@ function calculateCID(metadata) {
   return { solcVersion, cidV0, cidV1 };
 }
 
-function fetchJSONMetadata(cid, ipfs) {
+function fetchCID(cid, ipfs) {
   let response;
   if (cid[0] === 'Q') { // v0
     response = fetch(`${ipfs.origin}/ipfs/${cid}${ipfs.search}`);
@@ -168,7 +168,7 @@ function fetchJSONMetadata(cid, ipfs) {
       response = fetch(`${ipfs.protocol}//${cid}.ipfs.${ipfs.host}${ipfs.pathname}${ipfs.search}`);
     }
   }
-  return response.then(r => r.json());
+  return response;
 }
 
-export { fetchBytecode, extractCBOR, decodeCBOR, calculateCID, fetchJSONMetadata };
+export { fetchBytecode, extractCBOR, decodeCBOR, calculateCID, fetchCID };
-- 
2.47.3