From ff7c7e569ce0749f76bd282b5d16edadbc7e2201 Mon Sep 17 00:00:00 2001
From: Marcin Rataj <lidel@lidel.org>
Date: Mon, 13 Aug 2018 07:29:45 -0700
Subject: [PATCH] fix: dag.get return error on missing multicodec (#831)

Before this change it just failed silently for 'raw' DAGs
such as `bafkreigh2akiscaildcqabsyg3dfr6chu3fgpregiymsck7e7aqa4s52zy`

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>
---
 src/dag/get.js   | 17 +++++++---
 test/dag.spec.js | 82 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+), 5 deletions(-)
 create mode 100644 test/dag.spec.js

diff --git a/src/dag/get.js b/src/dag/get.js
index ead6a732c..f3b7027e2 100644
--- a/src/dag/get.js
+++ b/src/dag/get.js
@@ -7,6 +7,11 @@ const CID = require('cids')
 const waterfall = require('async/waterfall')
 const block = require('../block')
 
+const resolvers = {
+  'dag-cbor': dagCBOR.resolver,
+  'dag-pb': dagPB.resolver
+}
+
 module.exports = (send) => {
   return promisify((cid, path, options, callback) => {
     if (typeof path === 'function') {
@@ -40,12 +45,14 @@ module.exports = (send) => {
         })
       },
       (ipfsBlock, path, cb) => {
-        if (ipfsBlock.cid.codec === 'dag-cbor') {
-          dagCBOR.resolver.resolve(ipfsBlock.data, path, cb)
-        }
-        if (ipfsBlock.cid.codec === 'dag-pb') {
-          dagPB.resolver.resolve(ipfsBlock.data, path, cb)
+        const dagResolver = resolvers[ipfsBlock.cid.codec]
+        if (!dagResolver) {
+          const error = new Error('ipfs-api is missing DAG resolver for "' + ipfsBlock.cid.codec + '" multicodec')
+          error.missingMulticodec = ipfsBlock.cid.codec
+          cb(error)
+          return
         }
+        dagResolver.resolve(ipfsBlock.data, path, cb)
       }
     ], callback)
   })
diff --git a/test/dag.spec.js b/test/dag.spec.js
new file mode 100644
index 000000000..8224fc863
--- /dev/null
+++ b/test/dag.spec.js
@@ -0,0 +1,82 @@
+/* eslint-env mocha */
+/* eslint max-nested-callbacks: ["error", 8] */
+
+'use strict'
+
+const chai = require('chai')
+const dirtyChai = require('dirty-chai')
+const expect = chai.expect
+chai.use(dirtyChai)
+const series = require('async/series')
+const dagPB = require('ipld-dag-pb')
+const DAGNode = dagPB.DAGNode
+
+const IPFSApi = require('../src')
+const f = require('./utils/factory')
+
+let ipfsd
+let ipfs
+
+describe('.dag', function () {
+  this.timeout(20 * 1000)
+  before(function (done) {
+    series([
+      (cb) => f.spawn({ initOptions: { bits: 1024 } }, (err, _ipfsd) => {
+        expect(err).to.not.exist()
+        ipfsd = _ipfsd
+        ipfs = IPFSApi(_ipfsd.apiAddr)
+        cb()
+      })
+    ], done)
+  })
+
+  after((done) => {
+    if (!ipfsd) return done()
+    ipfsd.stop(done)
+  })
+
+  it('should be able to put and get a DAG node with format dag-pb', (done) => {
+    const data = Buffer.from('some data')
+    DAGNode.create(data, (err, node) => {
+      expect(err).to.not.exist()
+      ipfs.dag.put(node, {format: 'dag-pb', hashAlg: 'sha2-256'}, (err, cid) => {
+        expect(err).to.not.exist()
+        cid = cid.toV0()
+        expect(cid.codec).to.equal('dag-pb')
+        cid = cid.toBaseEncodedString('base58btc')
+        // expect(cid).to.equal('bafybeig3t3eugdchignsgkou3ly2mmy4ic4gtfor7inftnqn3yq4ws3a5u')
+        expect(cid).to.equal('Qmd7xRhW5f29QuBFtqu3oSD27iVy35NRB91XFjmKFhtgMr')
+        ipfs.dag.get(cid, (err, result) => {
+          expect(err).to.not.exist()
+          expect(result.value.data).to.deep.equal(data)
+          done()
+        })
+      })
+    })
+  })
+
+  it('should be able to put and get a DAG node with format dag-cbor', (done) => {
+    const cbor = {foo: 'dag-cbor-bar'}
+    ipfs.dag.put(cbor, {format: 'dag-cbor', hashAlg: 'sha2-256'}, (err, cid) => {
+      expect(err).to.not.exist()
+      expect(cid.codec).to.equal('dag-cbor')
+      cid = cid.toBaseEncodedString('base32')
+      expect(cid).to.equal('bafyreic6f672hnponukaacmk2mmt7vs324zkagvu4hcww6yba6kby25zce')
+      ipfs.dag.get(cid, (err, result) => {
+        expect(err).to.not.exist()
+        expect(result.value).to.deep.equal(cbor)
+        done()
+      })
+    })
+  })
+
+  it('should callback with error when missing DAG resolver for raw multicodec', (done) => {
+    // CIDv1 with multicodec = raw
+    const cid = 'bafkreigh2akiscaildcqabsyg3dfr6chu3fgpregiymsck7e7aqa4s52zy'
+    ipfs.dag.get(cid, (err, result) => {
+      expect(result).to.not.exist()
+      expect(err.message).to.equal('ipfs-api is missing DAG resolver for "raw" multicodec')
+      done()
+    })
+  })
+})