fix: add support for resolving to the middle of an IPLD block

see: ipfs-inactive/interface-js-ipfs-core#385

Author: Stebalien

src/core/components/resolve.js

@@ -34,17 +34,15 @@ module.exports = (self) => {
 
     const path = split.slice(3).join('/')
 
-    resolve(cid, path, (err, cid) => {
+    resolve(cid, path, (err, cid, remainder) => {
       if (err) return cb(err)
-      if (!cid) return cb(new Error('found non-link at given path'))
-      cb(null, `/ipfs/${cidToString(cid, { base: opts.cidBase })}`)
+      cb(null, `/ipfs/${cidToString(cid, { base: opts.cidBase })}${remainder ? '/' + remainder : ''}`)
     })
   })
 
   // Resolve the given CID + path to a CID.
   function resolve (cid, path, callback) {
-    let value
-
+    let value, remainder
     doUntil(
       (cb) => {
         self.block.get(cid, (err, block) => {
@@ -59,28 +57,27 @@ module.exports = (self) => {
           r.resolver.resolve(block.data, path, (err, result) => {
             if (err) return cb(err)
             value = result.value
-            path = result.remainderPath
+            remainder = result.remainderPath
             cb()
           })
         })
       },
       () => {
-        const endReached = !path || path === '/'
-
-        if (endReached) {
-          return true
-        }
-
-        if (value) {
+        if (value && value['/']) {
+          // If we've hit a CID, replace the current CID.
           cid = new CID(value['/'])
+          path = remainder
+        } else {
+          // We've hit a value. Return the current CID and the remaining path.
+          return true
         }
 
-        return false
+        // Continue resolving unless the path is empty.
+        return !path || path === '/'
       },
       (err) => {
         if (err) return callback(err)
-        if (value && value['/']) return callback(null, new CID(value['/']))
-        callback()
+        callback(null, cid, path)
       }
     )
   }

test/core/resolve.spec.js

@@ -0,0 +1,57 @@
+/* eslint max-nested-callbacks: ["error", 8] */
+/* eslint-env mocha */
+'use strict'
+
+const chai = require('chai')
+const dirtyChai = require('dirty-chai')
+const expect = chai.expect
+chai.use(dirtyChai)
+
+const IPFSFactory = require('ipfsd-ctl')
+const IPFS = require('../../src/core')
+
+describe('resolve', () => {
+  let ipfsd, ipfs
+
+  before(function (done) {
+    this.timeout(20 * 1000)
+
+    const factory = IPFSFactory.create({ type: 'proc' })
+
+    factory.spawn({
+      exec: IPFS,
+      initOptions: { bits: 512 },
+      config: { Bootstrap: [] }
+    }, (err, _ipfsd) => {
+      expect(err).to.not.exist()
+      ipfsd = _ipfsd
+      ipfs = _ipfsd.api
+      done()
+    })
+  })
+
+  after((done) => {
+    if (ipfsd) {
+      ipfsd.stop(done)
+    } else {
+      done()
+    }
+  })
+
+  it('should resolve an IPFS path non-link', (done) => {
+    const content = { path: { to: { file: 'foobar' } } }
+    const options = { format: 'dag-cbor', hashAlg: 'sha2-256' }
+
+    ipfs.dag.put(content, options, (err, cid) => {
+      expect(err).to.not.exist()
+
+      // FIXME: This should be /ipld/... but that's not supported yet.
+      const path = `/ipfs/${cid.toBaseEncodedString()}/path/to/file`
+      ipfs.resolve(path, (err, resolved) => {
+        expect(err).to.not.exist()
+        expect(resolved).to.equal(path)
+        done()
+      })
+    })
+  })
+})