refactor: default to base32 encoding for v1 CIDs

README.md

@@ -59,13 +59,13 @@ You can create an instance from a CID string or CID Buffer
 ```js
 const CID = require('cids')
 
-const cid = new CID('zdj7WkRPAX9o9nb9zPbXzwG7JEs78uyhwbUs8JSUayB98DWWY')
+const cid = new CID('bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsu')
 
 cid.version       // 1
 cid.codec         // 'dag-pb'
-cid.multibaseName // 'base58btc'
+cid.multibaseName // 'base32'
 cid.toString()
-// 'zdj7WkRPAX9o9nb9zPbXzwG7JEs78uyhwbUs8JSUayB98DWWY'
+// 'bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsu'
 ```
 
 or by specifying the [cid version](https://github.com/multiformats/cid#versions), [multicodec name](https://github.com/multiformats/multicodec/blob/master/table.csv) and [multihash](https://github.com/multiformats/multihash):
@@ -74,28 +74,28 @@ or by specifying the [cid version](https://github.com/multiformats/cid#versions)
 const CID = require('cids')
 const multihashing = require('multihashing-async')
 
-multihashing(Buffer.from('OMG!'), 'sha2-256', (err, hash) => {
-  const cid = new CID(1, 'dag-pb', hash)
-  console.log(cid.toString())
-  // zdj7WkRPAX9o9nb9zPbXzwG7JEs78uyhwbUs8JSUayB98DWWY
-})
+const hash = await multihashing(Buffer.from('OMG!'), 'sha2-256')
+const cid = new CID(1, 'dag-pb', hash)
+console.log(cid.toString())
+// bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsu
 ```
 
-The string form of CIDs currently defaults to `base58btc` flavour. (This is [soon to change to `base32`](https://github.com/ipfs/ipfs/issues/337). When creating a new instance you can optionally specify the default multibase to use when calling `toBaseEncodedString()` or `toString()`
+The string form of v1 CIDs defaults to `base32` encoding (v0 CIDs are always `base58btc` encoded). When creating a new instance you can optionally specify the default multibase to use when calling `toBaseEncodedString()` or `toString()`
 
 
 ```js
-const cid = new CID(1, 'raw', hash, 'base32')
+const cid = new CID(1, 'raw', hash, 'base64')
 console.log(cid.toString())
-// bafybeig6xv5nwphfmvcnektpnojts33jqcuam7bmye2pb54adnrtccjlsu
+// mAXASIN69ets85WVE0ipva5M5b2mAqAZ8LME08PeAG2MxCSuV
 ```
 
 If you construct an instance from a valid CID string, the base you provided will be preserved as the default.
 
 ```js
-const cid = new CID('bafkreigh2akiscaildcqabsyg3dfr6chu3fgpregiymsck7e7aqa4s52zy')
+// e.g. a base64url encoded CID
+const cid = new CID('uAXASIHJSUj5lkfuP5VPWf_VahvhARLRqPkF24QxY-lKaSqvV')
 cid.toString()
-// bafkreigh2akiscaildcqabsyg3dfr6chu3fgpregiymsck7e7aqa4s52zy
+// uAXASIHJSUj5lkfuP5VPWf_VahvhARLRqPkF24QxY-lKaSqvV
 ```
 
 
@@ -121,7 +121,7 @@ instance. Returns true if valid, false if not valid.
 
 `multihash` must be a `Buffer` instance of a valid [multihash](https://github.com/multiformats/multihash).
 
-`multibaseName` optional string. Must be a valid [multibase](https://github.com/multiformats/multibase/blob/master/multibase.csv) name. Default is `base58btc`.
+`multibaseName` optional string. Must be a valid [multibase](https://github.com/multiformats/multibase/blob/master/multibase.csv) name. Default is `base58btc` for v0 CIDs or `base32` for v1 CIDs.
 
 ### new CID(baseEncodedString)
 
@@ -169,7 +169,12 @@ Returns the CID encoded in version 1.
 
 #### cid.toBaseEncodedString(base=this.multibaseName)
 
-Returns a base encodec string of the CID. Defaults to the base encoding in `this.multibaseName`
+Returns a base encoded string of the CID. Defaults to the base encoding in `this.multibaseName`.
+
+The value of `this.multibaseName` depends on how the instance was constructed:
+
+1. If the CID was constructed from an object that already had a multibase (a string or an existing CID) then it retains that base.
+2. If the CID was constructed from an object that _did not_ have a multibase (a buffer, or by passing only version + codec + multihash to the constructor), then `multibaseName` will be `base58btc` for a v0 CID or `base32` for a v1 CID.
 
 #### cid.toString(base=this.multibaseName)
 

src/index.js

@@ -46,7 +46,7 @@ class CID {
    *   -> construct CID by parts
    * ```
    *
-   * @param {string|Buffer} version
+   * @param {string|Buffer|CID} version
    * @param {string} [codec]
    * @param {Buffer} [multihash]
    * @param {string} [multibaseName]
@@ -59,7 +59,7 @@ class CID {
    * new CID(<bs58 encoded multihash>)
    * new CID(<cid>)
    */
-  constructor (version, codec, multihash, multibaseName = 'base58btc') {
+  constructor (version, codec, multihash, multibaseName) {
     if (module.exports.isCID(version)) {
       // version is an exising CID instance
       const cid = version
@@ -95,13 +95,13 @@ class CID {
     if (Buffer.isBuffer(version)) {
       const firstByte = version.slice(0, 1)
       const v = parseInt(firstByte.toString('hex'), 16)
-      if (v === 0 || v === 1) {
+      if (v === 1) {
         // version is a CID buffer
         const cid = version
         this.version = v
         this.codec = multicodec.getCodec(cid.slice(1))
         this.multihash = multicodec.rmPrefix(cid.slice(1))
-        this.multibaseName = (v === 0) ? 'base58btc' : multibaseName
+        this.multibaseName = 'base32'
       } else {
         // version is a raw multihash buffer, so v0
         this.version = 0
@@ -133,7 +133,7 @@ class CID {
     /**
      * @type {string}
      */
-    this.multibaseName = multibaseName
+    this.multibaseName = multibaseName || (version === 0 ? 'base58btc' : 'base32')
 
     CID.validateCID(this)
   }

test/index.spec.js

@@ -32,6 +32,7 @@ describe('CID', () => {
       expect(cid).to.have.property('codec', 'dag-pb')
       expect(cid).to.have.property('version', 0)
       expect(cid).to.have.property('multihash').that.eql(multihash.fromB58String(mhStr))
+      expect(cid).to.have.property('multibaseName', 'base58btc')
 
       expect(cid.toBaseEncodedString()).to.be.eql(mhStr)
     })
@@ -46,6 +47,7 @@ describe('CID', () => {
         expect(cid).to.have.property('codec', 'dag-pb')
         expect(cid).to.have.property('version', 0)
         expect(cid).to.have.property('multihash').that.eql(mh)
+        expect(cid).to.have.property('multibaseName', 'base58btc')
 
         expect(cid.toBaseEncodedString()).to.eql(mhStr)
         done()
@@ -58,6 +60,7 @@ describe('CID', () => {
       expect(cid).to.have.property('codec', 'dag-pb')
       expect(cid).to.have.property('version', 0)
       expect(cid).to.have.property('multihash')
+      expect(cid).to.have.property('multibaseName', 'base58btc')
     })
 
     it('throws on invalid BS58Str multihash ', () => {
@@ -108,19 +111,21 @@ describe('CID', () => {
       expect(cid).to.have.property('codec', 'dag-pb')
       expect(cid).to.have.property('version', 1)
       expect(cid).to.have.property('multihash')
+      expect(cid).to.have.property('multibaseName', 'base58btc')
 
       expect(cid.toBaseEncodedString()).to.be.eql(cidStr)
     })
 
     it('handles CID (no multibase)', () => {
-      const cidStr = 'zdj7Wd8AMwqnhJGQCbFxBVodGSBG84TM7Hs1rcJuQMwTyfEDS'
+      const cidStr = 'bafybeidskjjd4zmr7oh6ku6wp72vvbxyibcli2r6if3ocdcy7jjjusvl2u'
       const cidBuf = Buffer.from('017012207252523e6591fb8fe553d67ff55a86f84044b46a3e4176e10c58fa529a4aabd5', 'hex')
 
       const cid = new CID(cidBuf)
 
       expect(cid).to.have.property('codec', 'dag-pb')
       expect(cid).to.have.property('version', 1)
       expect(cid).to.have.property('multihash')
+      expect(cid).to.have.property('multibaseName', 'base32')
 
       expect(cid.toBaseEncodedString()).to.be.eql(cidStr)
     })
@@ -131,6 +136,7 @@ describe('CID', () => {
       expect(cid).to.have.property('codec', 'dag-cbor')
       expect(cid).to.have.property('version', 1)
       expect(cid).to.have.property('multihash')
+      expect(cid).to.have.property('multibaseName', 'base32')
     })
 
     it('can roundtrip through cid.toBaseEncodedString()', () => {
@@ -140,6 +146,7 @@ describe('CID', () => {
       expect(cid1).to.have.property('codec').that.eql(cid2.codec)
       expect(cid1).to.have.property('version').that.eql(cid2.version)
       expect(cid1).to.have.property('multihash').that.eql(cid2.multihash)
+      expect(cid1).to.have.property('multibaseName').that.eql(cid2.multibaseName)
     })
 
     it('handles multibyte varint encoded codec codes', () => {
@@ -151,9 +158,11 @@ describe('CID', () => {
       expect(cid1).to.have.property('codec', 'eth-block')
       expect(cid1).to.have.property('version', 1)
       expect(cid1).to.have.property('multihash').that.eql(mh)
+      expect(cid1).to.have.property('multibaseName', 'base32')
       expect(cid2).to.have.property('codec', 'eth-block')
       expect(cid2).to.have.property('version', 1)
       expect(cid2).to.have.property('multihash').that.eql(mh)
+      expect(cid2).to.have.property('multibaseName', 'base32')
     })
 
     it('.prefix', () => {
@@ -199,9 +208,9 @@ describe('CID', () => {
 
     it('returns a string in the base provided', () => {
       const b58v1Str = 'zdj7Wd8AMwqnhJGQCbFxBVodGSBG84TM7Hs1rcJuQMwTyfEDS'
-      const b32v1Str = 'bafybeidskjjd4zmr7oh6ku6wp72vvbxyibcli2r6if3ocdcy7jjjusvl2u'
+      const b64urlv1Str = 'uAXASIHJSUj5lkfuP5VPWf_VahvhARLRqPkF24QxY-lKaSqvV'
       const cid = new CID(b58v1Str)
-      expect(cid.toString('base32')).to.equal(b32v1Str)
+      expect(cid.toString('base64url')).to.equal(b64urlv1Str)
     })
   })