upgrade cat

Author: nginnever

package.json

@@ -13,6 +13,7 @@
     "flatmap": "0.0.3",
     "glob": "^7.0.3",
     "ipfs-merkle-dag": "^0.6.0",
+    "is-ipfs": "^0.2.0",
     "isstream": "^0.1.2",
     "multiaddr": "^2.0.0",
     "multipart-stream": "^2.0.1",
@@ -93,4 +94,4 @@
     "url": "https://github.com/ipfs/js-ipfs-api/issues"
   },
   "homepage": "https://github.com/ipfs/js-ipfs-api"
-}
+}

src/api/cat.js

@@ -1,7 +1,32 @@
 'use strict'
 
-const argCommand = require('../cmd-helpers').argCommand
+const bs58 = require('bs58')
+const isIPFS = require('is-ipfs')
+const promisify = require('promisify-es6')
 
 module.exports = (send) => {
-  return argCommand(send, 'cat')
+  const cat = promisify((multihash, callback) => {
+    try {
+      multihash = cleanMultihash(multihash)
+    } catch (err) {
+      return callback(err)
+    }
+    send('cat', multihash, null, null, function (err, result) {
+      if (err) {
+        return callback(err)
+      }
+      return callback(null, result)
+    })
+  })
+  return cat
+}
+
+function cleanMultihash (multihash) {
+  if (!isIPFS.multihash(multihash)) {
+    throw new Error('not valid multihash')
+  }
+  if (Buffer.isBuffer(multihash)) {
+    return bs58.encode(multihash)
+  }
+  return multihash
 }