Update ipfs-http-client (for node >= 14)

Updates the client library and API usage to work with the latest
version, and more importantly, with current node.js LTS.

lib/utils/ipfs.js

@@ -8,10 +8,10 @@ class IPFS {
       config = { host: 'localhost', port: '5001', protocol: 'http' };
     }
     this._config = config;
-    this._ipfsAPI = ipfsClient(config);
+    this._ipfsAPI = ipfsClient.create(config);
   }
 
-  catAndMerge (contractData, deserialize) {
+  async catAndMerge (contractData, deserialize) {
     let data = {...contractData}; // data from ethers.js is not extensible. this copy the attributes in a new object
     // if no hash details are found simply return the data; nothing to merge
     if (!data.hashSize || data.hashSize === 0) {
@@ -22,20 +22,19 @@ class IPFS {
 
     return this.cat(data.ipfsHash)
       .then(deserialize)
-      .then((attributes) => {
+      .then(attributes => {
         return Object.assign({}, data, attributes);
       });
   }
 
-  add (data) {
-    return this._ipfsAPI
-      .add(ipfsClient.Buffer.from(data))
-      .then((res) => {
-        return this.decodeHash(res[0].hash);
+  async add (data) {
+    return this._ipfsAPI.add(data)
+      .then(res => {
+        return this.decodeHash(res.path);
       });
   }
 
-  cat (hashData) {
+  async cat (hashData) {
     let ipfsHash = hashData; // default - if it is a string
     if (Object.prototype.hasOwnProperty.call(hashData, 'hashSize')) {
       ipfsHash = this.encodeHash(hashData);
@@ -43,7 +42,12 @@ class IPFS {
     if (this._config['gatewayUrl']) {
       return fetch(`${this._config['gatewayUrl']}/${ipfsHash}`).then(r => r.text());
     } else {
-      return this._ipfsAPI.cat(ipfsHash);
+      const res = this._ipfsAPI.cat(ipfsHash);
+      let str = '';
+      for await (const buffer of res) {
+        str += buffer.toString();
+      }
+      return Promise.resolve(str);
     }
   }
 
@@ -66,7 +70,7 @@ class IPFS {
   }
 
   encodeHash (hashData) {
-    let digest = ipfsClient.Buffer.from(hashData.hashDigest.slice(2), 'hex');
+    const digest = Buffer.from(hashData.hashDigest.slice(2), 'hex');
     return multihashes.encode(digest, hashData.hashFunction, hashData.hashSize);
   }
 }