Hello wrapper library

lib/utils/ipfs.js

@@ -0,0 +1,59 @@
+const ipfsAPI = require('ipfs-api');
+const multihashes = require('multihashes');
+
+class IPFS {
+
+  constructor(config) {
+    this._ipfsAPI = ipfsAPI(config);
+    this._config = config;
+  }
+
+  catAndMerge(data, deserialize) {
+    // if no hash details are found simply return the data; nothing to merge
+    if (!data.hashSize || data.hashSize === 0) {
+      return data;
+    }
+    // merge ipfsHash (encoded from hashDigest, hashSize, hashFunction)
+    data.ipfsHash = this.encodeHash(data);
+
+    return this.cat(data)
+      .then(deserialize)
+      .then((attributes) => {
+        return Object.assign({}, data, attributes);
+      });
+  }
+
+  add(data) {
+    return this._ipfsAPI
+      .add(new this._ipfsAPI.Buffer(data))
+      .then((res) => {
+        return this.decodeHash(res[0].hash);
+      });
+  }
+
+  cat(hashData) {
+    let ipfsHash = hashData; // default - if it is a string
+    if (hashData.hasOwnProperty('hashSize')) {
+      ipfsHash = this.encodeHash(hashData);
+    }
+    return this._ipfsAPI.cat(ipfsHash);
+  }
+
+  decodeHash(ipfsHash) {
+    let multihash = multihashes.decode(multihashes.fromB58String(ipfsHash));
+    return {
+      hashDigest: '0x' + multihashes.toHexString(multihash.digest),
+      hashSize: multihash.length,
+      hashFunction: multihash.code,
+      ipfsHash: ipfsHash
+    };
+  }
+
+  encodeHash(hashData) {
+    let digest = this._ipfsAPI.Buffer.from(hashData.hashDigest.slice(2), 'hex');
+    return multihashes.encode(digest, hashData.hashFunction, hashData.hashSize);
+  }
+
+}
+
+module.exports = IPFS;