diff --git a/src/importer/dir-flat.js b/src/importer/dir-flat.js
index 70215ab8..a8d625b7 100644
--- a/src/importer/dir-flat.js
+++ b/src/importer/dir-flat.js
@@ -9,7 +9,6 @@ const DAGLink = dagPB.DAGLink
 const DAGNode = dagPB.DAGNode
 
 class DirFlat {
-
   constructor (props) {
     this._children = {}
     Object.assign(this, props)
@@ -81,7 +80,6 @@ class DirFlat {
       ],
       callback)
   }
-
 }
 
 module.exports = createDirFlat
diff --git a/src/importer/tree-builder.js b/src/importer/tree-builder.js
index 3d9b8054..039dcb83 100644
--- a/src/importer/tree-builder.js
+++ b/src/importer/tree-builder.js
@@ -215,4 +215,3 @@ function createTreeBuilder (ipldResolver, _options) {
 function notEmpty (str) {
   return Boolean(str)
 }
-
diff --git a/test/browser.js b/test/browser.js
index 4cc7f65b..9f319aae 100644
--- a/test/browser.js
+++ b/test/browser.js
@@ -45,7 +45,6 @@ describe('IPFS data importing tests on the Browser', function () {
   require('./test-consumable-buffer')
   require('./test-consumable-hash')
   require('./test-hamt')
-  require('./test-exporter')(repo)
   require('./test-importer')(repo)
   require('./test-importer-flush')(repo)
   require('./test-import-export')(repo)
diff --git a/test/test-consumable-hash.js b/test/test-consumable-hash.js
index 0807fed0..8eed3cb8 100644
--- a/test/test-consumable-hash.js
+++ b/test/test-consumable-hash.js
@@ -1,7 +1,9 @@
 /* eslint-env mocha */
 'use strict'
 
-const expect = require('chai').expect
+const chai = require('chai')
+chai.use(require('dirty-chai'))
+const expect = chai.expect
 const crypto = require('crypto')
 const whilst = require('async/whilst')
 
@@ -18,7 +20,7 @@ describe('consumable hash', () => {
 
   it('can take a 0 length value', (callback) => {
     hash('some value').take(0, (err, result) => {
-      expect(err).to.not.exist
+      expect(err).to.not.exist()
       expect(result).to.be.eql(0)
       callback()
     })
@@ -26,7 +28,7 @@ describe('consumable hash', () => {
 
   it('can take a 10 bit value', (callback) => {
     hash('some value').take(10, (err, result) => {
-      expect(err).to.not.exist
+      expect(err).to.not.exist()
       expect(result).to.be.eql(110)
       callback()
     })
@@ -39,7 +41,7 @@ describe('consumable hash', () => {
       () => iter > 0,
       (callback) => {
         h.take(10, (err, result) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           values.push(result)
           expect(result).to.be.below(1024)
           expect(result).to.be.above(0)
@@ -61,7 +63,7 @@ describe('consumable hash', () => {
       () => iter > 0,
       (callback) => {
         h.take(10, (err, result) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           values.push(result)
           expect(result).to.be.eql(values.shift())
           iter--
diff --git a/test/test-dirbuilder-sharding.js b/test/test-dirbuilder-sharding.js
index 18300724..c7ea7741 100644
--- a/test/test-dirbuilder-sharding.js
+++ b/test/test-dirbuilder-sharding.js
@@ -4,14 +4,16 @@
 const importer = require('./../src').importer
 const exporter = require('./../src').exporter
 
+const chai = require('chai')
+chai.use(require('dirty-chai'))
+const expect = chai.expect
 const mh = require('multihashes')
-const expect = require('chai').expect
 const BlockService = require('ipfs-block-service')
 const IPLDResolver = require('ipld-resolver')
 const pull = require('pull-stream')
 const pushable = require('pull-pushable')
 const whilst = require('async/whilst')
-const timers = require('timers')
+const setImmediate = require('async/setImmediate')
 const leftPad = require('left-pad')
 
 module.exports = (repo) => {
@@ -40,12 +42,12 @@ module.exports = (repo) => {
           ]),
           importer(ipldResolver, options),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(2)
             expect(nodes[0].path).to.be.eql('a/b')
             expect(nodes[1].path).to.be.eql('a')
             nonShardedHash = nodes[1].multihash
-            expect(nonShardedHash).to.exist
+            expect(nonShardedHash).to.exist()
             done()
           })
         )
@@ -65,7 +67,7 @@ module.exports = (repo) => {
           ]),
           importer(ipldResolver, options),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(2)
             expect(nodes[0].path).to.be.eql('a/b')
             expect(nodes[1].path).to.be.eql('a')
@@ -81,7 +83,7 @@ module.exports = (repo) => {
         pull(
           exporter(nonShardedHash, ipldResolver),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(2)
             const expectedHash = mh.toB58String(nonShardedHash)
             expect(nodes[0].path).to.be.eql(expectedHash)
@@ -96,7 +98,7 @@ module.exports = (repo) => {
         )
 
         function collected (err, content) {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(content.length).to.be.eql(1)
           expect(content[0].toString()).to.be.eql('i have the best bytes')
           done()
@@ -107,7 +109,7 @@ module.exports = (repo) => {
         pull(
           exporter(shardedHash, ipldResolver),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(2)
             const expectedHash = mh.toB58String(shardedHash)
             expect(nodes[0].path).to.be.eql(expectedHash)
@@ -122,7 +124,7 @@ module.exports = (repo) => {
         )
 
         function collected (err, content) {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(content.length).to.be.eql(1)
           expect(content[0].toString()).to.be.eql('i have the best bytes')
           done()
@@ -140,7 +142,7 @@ module.exports = (repo) => {
           push,
           importer(ipldResolver),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(maxDirs + 1)
             const last = nodes[nodes.length - 1]
             expect(last.path).to.be.eql('big')
@@ -162,10 +164,10 @@ module.exports = (repo) => {
               content: pull.values([new Buffer(i.toString())])
             }
             push.push(pushable)
-            timers.setTimeout(callback, 1)
+            setImmediate(callback)
           },
           (err) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             push.end()
           }
         )
@@ -188,13 +190,13 @@ module.exports = (repo) => {
             }
 
             function collected (err, content) {
-              expect(err).to.not.exist
+              expect(err).to.not.exist()
               entries[node.path] = { content: content.toString() }
               callback(null, node)
             }
           }),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             const paths = Object.keys(entries).sort()
             expect(paths.length).to.be.eql(2001)
             paths.forEach(eachPath)
@@ -207,8 +209,8 @@ module.exports = (repo) => {
             // first dir
             expect(path).to.be.eql(mh.toB58String(rootHash))
             const entry = entries[path]
-            expect(entry).to.exist
-            expect(entry.content).to.not.exist
+            expect(entry).to.exist()
+            expect(entry.content).to.not.exist()
             return
           }
           // dir entries
@@ -232,7 +234,7 @@ module.exports = (repo) => {
           push,
           importer(ipldResolver),
           pull.collect((err, nodes) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             const last = nodes[nodes.length - 1]
             expect(last.path).to.be.eql('big')
             rootHash = last.multihash
@@ -265,10 +267,10 @@ module.exports = (repo) => {
               i = 0
               depth++
             }
-            timers.setTimeout(callback, 1)
+            setImmediate(callback)
           },
           (err) => {
-            expect(err).to.not.exist
+            expect(err).to.not.exist()
             push.end()
           }
         )
@@ -290,7 +292,7 @@ module.exports = (repo) => {
             }
 
             function collected (err, content) {
-              expect(err).to.not.exist
+              expect(err).to.not.exist()
               entries[node.path] = { content: content.toString() }
               callback(null, node)
             }
@@ -299,7 +301,7 @@ module.exports = (repo) => {
         )
 
         function collected (err, nodes) {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           const paths = Object.keys(entries).sort()
           expect(paths.length).to.be.eql(maxDepth * maxDirs + maxDepth)
           let index = 0
@@ -314,8 +316,8 @@ module.exports = (repo) => {
                 expect(path).to.be.eql(mh.toB58String(rootHash))
               }
               const entry = entries[path]
-              expect(entry).to.exist
-              expect(entry.content).to.not.exist
+              expect(entry).to.exist()
+              expect(entry.content).to.not.exist()
             } else {
               // dir entries
               const pathElements = path.split('/')
diff --git a/test/test-hamt.js b/test/test-hamt.js
index 899f46a1..4ae49ed2 100644
--- a/test/test-hamt.js
+++ b/test/test-hamt.js
@@ -1,8 +1,10 @@
 /* eslint-env mocha */
 'use strict'
 
+const chai = require('chai')
+chai.use(require('dirty-chai'))
+const expect = chai.expect
 const crypto = require('crypto')
-const expect = require('chai').expect
 const each = require('async/each')
 const eachSeries = require('async/eachSeries')
 
@@ -28,8 +30,8 @@ describe('HAMT', () => {
 
     it('get unknown key returns undefined', (callback) => {
       bucket.get('unknown', (err, result) => {
-        expect(err).to.not.exist
-        expect(result).to.be.undefined
+        expect(err).to.not.exist()
+        expect(result).to.be.undefined()
         callback()
       })
     })
@@ -40,7 +42,7 @@ describe('HAMT', () => {
 
     it('can get that value', (callback) => {
       bucket.get('key', (err, result) => {
-        expect(err).to.not.exist
+        expect(err).to.not.exist()
         expect(result).to.be.eql('value')
         callback()
       })
@@ -52,7 +54,7 @@ describe('HAMT', () => {
 
     it('can get that value', (callback) => {
       bucket.get('key', (err, result) => {
-        expect(err).to.not.exist
+        expect(err).to.not.exist()
         expect(result).to.be.eql('a different value')
         callback()
       })
@@ -68,8 +70,8 @@ describe('HAMT', () => {
 
     it('get deleted key returns undefined', (callback) => {
       bucket.get('key', (err, result) => {
-        expect(err).to.not.exist
-        expect(result).to.be.undefined
+        expect(err).to.not.exist()
+        expect(result).to.be.undefined()
         callback()
       })
     })
@@ -104,19 +106,19 @@ describe('HAMT', () => {
         }
 
         bucket.get(head, (err, value) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(value).to.be.eql(head)
           bucket.del(head, afterDel)
         })
 
         function afterDel (err) {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           bucket.get(head, afterGet)
         }
 
         function afterGet (err, value) {
-          expect(err).to.not.exist
-          expect(value).to.be.undefined
+          expect(err).to.not.exist()
+          expect(value).to.be.undefined()
 
           each(
             keys,
@@ -128,14 +130,14 @@ describe('HAMT', () => {
 
       function onEachKey (key, callback) {
         bucket.get(key, (err, value) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(value).to.be.eql(key)
           callback()
         })
       }
 
       function reiterate (err) {
-        expect(err).to.not.exist
+        expect(err).to.not.exist()
         // break from stack on next iteration
         process.nextTick(iterate)
       }
@@ -147,7 +149,7 @@ describe('HAMT', () => {
 
     it('can still find sole head', (callback) => {
       bucket.get(masterHead, (err, value) => {
-        expect(err).to.not.exist
+        expect(err).to.not.exist()
         expect(value).to.be.eql(masterHead)
         callback()
       })
@@ -172,7 +174,7 @@ describe('HAMT', () => {
       }
 
       eachSeries(keys, (key, callback) => bucket.put(key, key, callback), (err) => {
-        expect(err).to.not.exist
+        expect(err).to.not.exist()
         callback()
       })
     })
diff --git a/test/test-importer-flush.js b/test/test-importer-flush.js
index 5c58188a..87b6fc72 100644
--- a/test/test-importer-flush.js
+++ b/test/test-importer-flush.js
@@ -3,7 +3,9 @@
 
 const createImporter = require('./../src').importer
 
-const expect = require('chai').expect
+const chai = require('chai')
+chai.use(require('dirty-chai'))
+const expect = chai.expect
 const BlockService = require('ipfs-block-service')
 const IPLDResolver = require('ipld-resolver')
 const pull = require('pull-stream')
@@ -29,7 +31,7 @@ module.exports = (repo) => {
           return node
         }),
         pull.collect((err, files) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(files.length).to.be.eql(1)
           done()
         })
@@ -41,8 +43,8 @@ module.exports = (repo) => {
       })
 
       importer.flush((err, hash) => {
-        expect(err).to.not.exist
-        expect(Buffer.isBuffer(hash)).to.be.true
+        expect(err).to.not.exist()
+        expect(Buffer.isBuffer(hash)).to.be.true()
         source.end()
       })
     })
@@ -64,7 +66,7 @@ module.exports = (repo) => {
           return node
         }),
         pull.collect((err, files) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(count).to.be.eql(2)
           done()
         })
@@ -76,8 +78,8 @@ module.exports = (repo) => {
       })
 
       importer.flush((err, hash) => {
-        expect(err).to.not.exist
-        expect(Buffer.isBuffer(hash)).to.be.true
+        expect(err).to.not.exist()
+        expect(Buffer.isBuffer(hash)).to.be.true()
         source.end()
       })
     })
@@ -102,7 +104,7 @@ module.exports = (repo) => {
           return node
         }),
         pull.collect((err, files) => {
-          expect(err).to.not.exist
+          expect(err).to.not.exist()
           expect(count).to.be.eql(2)
           done()
         })
@@ -134,8 +136,8 @@ module.exports = (repo) => {
           currentDir = newDir
         }
         importer.flush((err, hash) => {
-          expect(err).to.not.exist
-          expect(Buffer.isBuffer(hash)).to.be.true
+          expect(err).to.not.exist()
+          expect(Buffer.isBuffer(hash)).to.be.true()
           testAllYielded(tree)
           if (currentDir.depth < maxDepth) {
             pushAndFlush()
@@ -149,7 +151,7 @@ module.exports = (repo) => {
       function markDirAsYielded (node) {
         const dir = findDir(tree, node.path)
         if (node.path === dir.path) {
-          expect(dir.yielded).to.be.false
+          expect(dir.yielded).to.be.false()
           dir.yielded = true
         }
       }
@@ -169,7 +171,7 @@ module.exports = (repo) => {
 
       function testAllYielded (tree) {
         if (tree.depth) {
-          expect(tree.yielded).to.be.true
+          expect(tree.yielded).to.be.true()
         }
         const childrenNames = Object.keys(tree.children)
         childrenNames.forEach((childName) => {