feat: add cidBase option to resolve

License: MIT
Signed-off-by: Alan Shaw <alan.shaw@protocol.ai>

Author: Alan Shaw

src/resolve.js

@@ -1,10 +1,8 @@
 'use strict'
 
 const promisify = require('promisify-es6')
-
-const transform = function (res, callback) {
-  callback(null, res.Path)
-}
+const multibase = require('multibase')
+const CID = require('cids')
 
 module.exports = (send) => {
   return promisify((args, opts, callback) => {
@@ -13,6 +11,40 @@ module.exports = (send) => {
       opts = {}
     }
 
+    opts = opts || {}
+
+    if (opts.cidBase) {
+      opts['cid-base'] = opts.cidBase
+      delete opts.cidBase
+    }
+
+    const transform = (res, callback) => {
+      if (!opts['cid-base']) {
+        return callback(null, res.Path)
+      }
+
+      // FIXME: remove when go-ipfs supports ?cid-base for /api/v0/resolve
+      // https://github.com/ipfs/go-ipfs/pull/5777#issuecomment-439838555
+      const parts = res.Path.split('/') // ['', 'ipfs', 'QmHash', ...]
+
+      if (multibase.isEncoded(parts[2]) !== opts['cid-base']) {
+        try {
+          let cid = new CID(parts[2])
+
+          if (cid.version === 0 && opts['cid-base'] !== 'base58btc') {
+            cid = cid.toV1()
+          }
+
+          parts[2] = cid.toBaseEncodedString(opts['cid-base'])
+          res.Path = parts.join('/')
+        } catch (err) {
+          return callback(err)
+        }
+      }
+
+      callback(null, res.Path)
+    }
+
     send.andTransform({
       path: 'resolve',
       args: args,