diff --git a/Makefile b/Makefile
index ad8b097e4e..2fa367e8ff 100644
--- a/Makefile
+++ b/Makefile
@@ -63,79 +63,79 @@ test-jsapi:
 
 test-unit:
 	@printf "==> [Test :: Unit]\n"
-	$(call test_node,unit) test/acceptance/*.js \
-		--growl \
-		test/*.js
+	$(call test_node,unit) test/unit/*.spec.js \
+		test/node-unit/*.spec.js \
+		--growl
 
 test-integration:
 	@printf "==> [Test :: Integrations]\n"
 	$(call test_node,integration) --timeout 5000 \
-		test/integration/*.js
+		test/integration/*.spec.js
 
 test-compilers:
 	@printf "==> [Test :: Compilers]\n"
 	$(call test_node,compilers) --compilers coffee:coffee-script/register,foo:./test/compiler/foo \
-		test/acceptance/test.coffee \
-		test/acceptance/test.foo
+		test/compiler/test.coffee \
+		test/compiler/test.foo
 
 test-requires:
 	@printf "==> [Test :: Requires]\n"
 	$(call test_node,requires) --compilers coffee:coffee-script/register \
-		--require test/acceptance/require/a.js \
-		--require test/acceptance/require/b.coffee \
-		--require test/acceptance/require/c.js \
-		--require test/acceptance/require/d.coffee \
-		test/acceptance/require/require.spec.js
+		--require test/require/a.js \
+		--require test/require/b.coffee \
+		--require test/require/c.js \
+		--require test/require/d.coffee \
+		test/require/require.spec.js
 
 test-bdd:
 	@printf "==> [Test :: BDD]\n"
 	$(call test_node,bdd) --ui bdd \
-		test/acceptance/interfaces/bdd.spec
+		test/interfaces/bdd.spec
 
 test-tdd:
 	@printf "==> [Test :: TDD]\n"
 	$(call test_node,tdd) --ui tdd \
-		test/acceptance/interfaces/tdd.spec
+		test/interfaces/tdd.spec
 
 test-qunit:
 	@printf "==> [Test :: QUnit]\n"
 	$(call test_node,qunit) --ui qunit \
-		test/acceptance/interfaces/qunit.spec
+		test/interfaces/qunit.spec
 
 test-exports:
 	@printf "==> [Test :: Exports]\n"
 	$(call test_node,exports) --ui exports \
-		test/acceptance/interfaces/exports.spec
+		test/interfaces/exports.spec
 
 test-glob:
 	@printf "==> [Test :: Glob]\n"
-	bash ./test/acceptance/glob/glob.sh
+	bash ./test/glob/glob.sh
 
 test-reporters:
 	@printf "==> [Test :: Reporters]\n"
-	$(call test_node,reporters) test/reporters/*.js
+	$(call test_node,reporters) test/reporters/*.spec.js
 
 test-only:
 	@printf "==> [Test :: Only]\n"
 	$(call test_node,only-tdd) --ui tdd \
-		test/acceptance/misc/only/tdd.spec
+		test/misc/only/tdd.spec
 
 	$(call test_node,only-bdd) --ui bdd \
-		test/acceptance/misc/only/bdd.spec
+		test/misc/only/bdd.spec
 
 	$(call test_node,only-bdd-require) --ui qunit \
-		test/acceptance/misc/only/bdd-require.spec
+		test/misc/only/bdd-require.spec
 
 test-global-only:
 	@printf "==> [Test :: Global Only]\n"
 	$(call test_node,global-only-tdd) --ui tdd \
-		test/acceptance/misc/only/global/tdd.spec
+		test/misc/only/global/tdd.spec
 
 	$(call test_node,global-only-bdd) --ui bdd \
-		test/acceptance/misc/only/global/bdd.spec
+		test/misc/only/global/bdd.spec
 
 	$(call test_node,global-only-qunit) --ui qunit \
-		test/acceptance/misc/only/global/qunit.spec
+		test/misc/only/global/qunit.spec
 
 test-mocha:
 	@printf "==> [Test :: Mocha]\n"
@@ -144,19 +144,19 @@ test-mocha:
 non-tty:
 	@printf "==> [Test :: Non-TTY]\n"
 	$(call test_node,non-tty-dot) --reporter dot \
-		test/acceptance/interfaces/bdd.spec 2>&1 > /tmp/dot.out
+		test/interfaces/bdd.spec 2>&1 > /tmp/dot.out
 
 	@echo dot:
 	@cat /tmp/dot.out
 
 	$(call test_node,non-tty-list) --reporter list \
-		test/acceptance/interfaces/bdd.spec 2>&1 > /tmp/list.out
+		test/interfaces/bdd.spec 2>&1 > /tmp/list.out
 
 	@echo list:
 	@cat /tmp/list.out
 
 	$(call test_node,non-tty-spec) --reporter spec \
-		test/acceptance/interfaces/bdd.spec 2>&1 > /tmp/spec.out
+		test/interfaces/bdd.spec 2>&1 > /tmp/spec.out
 
 	@echo spec:
 	@cat /tmp/spec.out
diff --git a/karma.conf.js b/karma.conf.js
index 2ba9d4d2e1..c99150e2f9 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -18,14 +18,7 @@ module.exports = function (config) {
       // we use the BDD interface for all of the tests that
       // aren't interface-specific.
       'test/browser-fixtures/bdd.fixture.js',
-      'test/acceptance/*.spec.js'
-    ],
-    exclude: [
-      'test/acceptance/http.spec.js',
-      'test/acceptance/fs.spec.js',
-      'test/acceptance/file-utils.spec.js',
-      'test/acceptance/require/**/*.js',
-      'test/acceptance/misc/**/*.js'
+      'test/unit/*.spec.js'
     ],
     preprocessors: {
       'test/**/*.js': ['browserify']
@@ -128,7 +121,7 @@ module.exports = function (config) {
     }
     cfg.files = [
       'test/browser-fixtures/' + ui + '.fixture.js',
-      'test/acceptance/interfaces/' + ui + '.spec.js'
+      'test/interfaces/' + ui + '.spec.js'
     ];
   } else if (cfg.sauceLabs) {
     cfg.sauceLabs.testName = 'Unit Tests';
diff --git a/test/browser-fixtures/bdd.fixture.js b/test/browser-fixtures/bdd.fixture.js
index d19993676a..5fe802f74a 100644
--- a/test/browser-fixtures/bdd.fixture.js
+++ b/test/browser-fixtures/bdd.fixture.js
@@ -2,5 +2,7 @@
 
 /* eslint-env browser */
 
+process.stdout = require('browser-stdout')();
+
 window.mocha.timeout(200)
   .ui('bdd');
diff --git a/test/browser-fixtures/exports.fixture.js b/test/browser-fixtures/exports.fixture.js
index 97b8b97cbe..a4c25cff99 100644
--- a/test/browser-fixtures/exports.fixture.js
+++ b/test/browser-fixtures/exports.fixture.js
@@ -2,5 +2,7 @@
 
 /* eslint-env browser */
 
+process.stdout = require('browser-stdout')();
+
 window.mocha.timeout(200)
   .ui('exports');
diff --git a/test/browser-fixtures/qunit.fixture.js b/test/browser-fixtures/qunit.fixture.js
index a3fd887940..79b49498d5 100644
--- a/test/browser-fixtures/qunit.fixture.js
+++ b/test/browser-fixtures/qunit.fixture.js
@@ -2,5 +2,7 @@
 
 /* eslint-env browser */
 
+process.stdout = require('browser-stdout')();
+
 window.mocha.timeout(200)
   .ui('qunit');
diff --git a/test/browser-fixtures/tdd.fixture.js b/test/browser-fixtures/tdd.fixture.js
index 0c36f0c54b..2fdc8f758c 100644
--- a/test/browser-fixtures/tdd.fixture.js
+++ b/test/browser-fixtures/tdd.fixture.js
@@ -2,5 +2,7 @@
 
 /* eslint-env browser */
 
+process.stdout = require('browser-stdout')();
+
 window.mocha.timeout(200)
   .ui('tdd');
diff --git a/test/browser/README.md b/test/browser/README.md
new file mode 100644
index 0000000000..15e4178b3e
--- /dev/null
+++ b/test/browser/README.md
@@ -0,0 +1,3 @@
+These files need to be run manually by loading the `.html` file(s) in a browser.
+
+It would be awesome if we could automate that!
diff --git a/test/acceptance/test.coffee b/test/compiler/test.coffee
similarity index 100%
rename from test/acceptance/test.coffee
rename to test/compiler/test.coffee
diff --git a/test/acceptance/test.foo b/test/compiler/test.foo
similarity index 100%
rename from test/acceptance/test.foo
rename to test/compiler/test.foo
diff --git a/test/acceptance/glob/glob.sh b/test/glob/glob.sh
similarity index 84%
rename from test/acceptance/glob/glob.sh
rename to test/glob/glob.sh
index 823ba07fb9..c0cb21d3f8 100755
--- a/test/acceptance/glob/glob.sh
+++ b/test/glob/glob.sh
@@ -7,7 +7,7 @@ cd $SCRIPT_DIR || {
     exit 1
 }
 
-../../../bin/mocha -R json-stream  ./*.js > /tmp/mocha-glob.txt || {
+../../bin/mocha -R json-stream  ./*.js > /tmp/mocha-glob.txt || {
     echo Globbing ./*.js in `pwd` failed.
     exit 1
 }
@@ -17,7 +17,7 @@ cat /tmp/mocha-glob.txt | grep -q -F '["end",{"suites":1,"tests":1,"passes":1,"p
     exit 1
 }
 
-../../../bin/mocha -R json-stream ./*-none.js 2> /tmp/mocha-glob.txt && {
+../../bin/mocha -R json-stream ./*-none.js 2> /tmp/mocha-glob.txt && {
     echo Globbing './*-none.js' in `pwd` failed.
     exit 1
 }
@@ -27,7 +27,7 @@ cat /tmp/mocha-glob.txt | grep -q -F 'Could not find any test files matching pat
     exit 1
 }
 
-../../../bin/mocha -R json-stream  ./*.js ./*-none.js >& /tmp/mocha-glob.txt || {
+../../bin/mocha -R json-stream  ./*.js ./*-none.js >& /tmp/mocha-glob.txt || {
     echo Globbing ./*.js ./*-none.js in `pwd` failed.
     exit 1
 }
@@ -43,7 +43,7 @@ cat /tmp/mocha-glob.txt | grep -q -F 'Could not find any test files matching pat
 # In windows, the shell passes globs unexpanded, executables do expansion if they support it.
 # Adding single-quotes around the glob below makes bash pass glob unexpanded,
 #     allowing us to test windows-style globbing in bash.
-../../../bin/mocha -R json-stream  './*.js' > /tmp/mocha-glob.txt || {
+../../bin/mocha -R json-stream  './*.js' > /tmp/mocha-glob.txt || {
     echo Globbing './*.js' in `pwd` failed.
     exit 1
 }
@@ -53,7 +53,7 @@ cat /tmp/mocha-glob.txt | grep -q -F '["end",{"suites":1,"tests":1,"passes":1,"p
     exit 1
 }
 
-../../../bin/mocha -R json-stream  './*-none.js' 2> /tmp/mocha-glob.txt && {
+../../bin/mocha -R json-stream  './*-none.js' 2> /tmp/mocha-glob.txt && {
     echo Globbing './*-none.js' in `pwd` failed.
     exit 1
 }
diff --git a/test/acceptance/glob/glob.spec.js b/test/glob/glob.spec.js
similarity index 100%
rename from test/acceptance/glob/glob.spec.js
rename to test/glob/glob.spec.js
diff --git a/test/acceptance/interfaces/bdd.spec.js b/test/interfaces/bdd.spec.js
similarity index 100%
rename from test/acceptance/interfaces/bdd.spec.js
rename to test/interfaces/bdd.spec.js
diff --git a/test/acceptance/interfaces/exports.spec.js b/test/interfaces/exports.spec.js
similarity index 100%
rename from test/acceptance/interfaces/exports.spec.js
rename to test/interfaces/exports.spec.js
diff --git a/test/acceptance/interfaces/qunit.spec.js b/test/interfaces/qunit.spec.js
similarity index 100%
rename from test/acceptance/interfaces/qunit.spec.js
rename to test/interfaces/qunit.spec.js
diff --git a/test/acceptance/interfaces/tdd.spec.js b/test/interfaces/tdd.spec.js
similarity index 100%
rename from test/acceptance/interfaces/tdd.spec.js
rename to test/interfaces/tdd.spec.js
diff --git a/test/jsapi/index.js b/test/jsapi/index.js
index 42133578e0..430a205250 100644
--- a/test/jsapi/index.js
+++ b/test/jsapi/index.js
@@ -12,16 +12,16 @@ var mocha = new Mocha({
 // mocha.reporter('spec');
 require('should');
 
-mocha.addFile('test/suite.spec.js');
-mocha.addFile('test/runner.spec.js');
-mocha.addFile('test/runnable.spec.js');
-mocha.addFile('test/hook-sync.spec.js');
-mocha.addFile('test/hook-sync-nested.spec.js');
-mocha.addFile('test/hook-async.spec.js');
-mocha.addFile('test/acceptance/duration.spec.js');
-mocha.addFile('test/acceptance/fs.spec.js');
-mocha.addFile('test/acceptance/globals.spec.js');
-mocha.addFile('test/acceptance/timeout.spec.js');
+mocha.addFile('test/unit/suite.spec.js');
+mocha.addFile('test/unit/runner.spec.js');
+mocha.addFile('test/unit/runnable.spec.js');
+mocha.addFile('test/unit/hook-sync.spec.js');
+mocha.addFile('test/unit/hook-sync-nested.spec.js');
+mocha.addFile('test/unit/hook-async.spec.js');
+mocha.addFile('test/unit/duration.spec.js');
+mocha.addFile('test/node-unit/fs.spec.js');
+mocha.addFile('test/unit/globals.spec.js');
+mocha.addFile('test/unit/timeout.spec.js');
 
 mocha.run(function () {
   console.log('done');
diff --git a/test/acceptance/misc/exit.spec.js b/test/misc/exit.spec.js
similarity index 100%
rename from test/acceptance/misc/exit.spec.js
rename to test/misc/exit.spec.js
diff --git a/test/acceptance/misc/many.spec.js b/test/misc/many.spec.js
similarity index 100%
rename from test/acceptance/misc/many.spec.js
rename to test/misc/many.spec.js
diff --git a/test/acceptance/misc/nontty.spec.js b/test/misc/nontty.spec.js
similarity index 100%
rename from test/acceptance/misc/nontty.spec.js
rename to test/misc/nontty.spec.js
diff --git a/test/acceptance/misc/only/bdd-require.spec.js b/test/misc/only/bdd-require.spec.js
similarity index 90%
rename from test/acceptance/misc/only/bdd-require.spec.js
rename to test/misc/only/bdd-require.spec.js
index 14710c4cd2..1c90d7acda 100644
--- a/test/acceptance/misc/only/bdd-require.spec.js
+++ b/test/misc/only/bdd-require.spec.js
@@ -2,7 +2,7 @@
 
 /* jshint node: true */
 
-var mocha = require('../../../../lib/mocha');
+var mocha = require('../../../lib/mocha');
 
 var beforeEach = mocha.beforeEach;
 var it = mocha.it;
diff --git a/test/acceptance/misc/only/bdd.spec.js b/test/misc/only/bdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/bdd.spec.js
rename to test/misc/only/bdd.spec.js
diff --git a/test/acceptance/misc/only/global/bdd.spec.js b/test/misc/only/global/bdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/global/bdd.spec.js
rename to test/misc/only/global/bdd.spec.js
diff --git a/test/acceptance/misc/only/global/qunit.spec.js b/test/misc/only/global/qunit.spec.js
similarity index 100%
rename from test/acceptance/misc/only/global/qunit.spec.js
rename to test/misc/only/global/qunit.spec.js
diff --git a/test/acceptance/misc/only/global/tdd.spec.js b/test/misc/only/global/tdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/global/tdd.spec.js
rename to test/misc/only/global/tdd.spec.js
diff --git a/test/acceptance/misc/only/qunit.spec.js b/test/misc/only/qunit.spec.js
similarity index 100%
rename from test/acceptance/misc/only/qunit.spec.js
rename to test/misc/only/qunit.spec.js
diff --git a/test/acceptance/misc/only/tdd.spec.js b/test/misc/only/tdd.spec.js
similarity index 100%
rename from test/acceptance/misc/only/tdd.spec.js
rename to test/misc/only/tdd.spec.js
diff --git a/test/color.spec.js b/test/node-unit/color.spec.js
similarity index 100%
rename from test/color.spec.js
rename to test/node-unit/color.spec.js
diff --git a/test/acceptance/file-utils.spec.js b/test/node-unit/file-utils.spec.js
similarity index 100%
rename from test/acceptance/file-utils.spec.js
rename to test/node-unit/file-utils.spec.js
diff --git a/test/acceptance/fs.spec.js b/test/node-unit/fs.spec.js
similarity index 100%
rename from test/acceptance/fs.spec.js
rename to test/node-unit/fs.spec.js
diff --git a/test/http-meta-2.spec.js b/test/node-unit/http-meta-2.spec.js
similarity index 100%
rename from test/http-meta-2.spec.js
rename to test/node-unit/http-meta-2.spec.js
diff --git a/test/http-meta.spec.js b/test/node-unit/http-meta.spec.js
similarity index 100%
rename from test/http-meta.spec.js
rename to test/node-unit/http-meta.spec.js
diff --git a/test/acceptance/http.spec.js b/test/node-unit/http.spec.js
similarity index 100%
rename from test/acceptance/http.spec.js
rename to test/node-unit/http.spec.js
diff --git a/test/node-unit/stack-trace-filter.spec.js b/test/node-unit/stack-trace-filter.spec.js
new file mode 100644
index 0000000000..72ce67a206
--- /dev/null
+++ b/test/node-unit/stack-trace-filter.spec.js
@@ -0,0 +1,156 @@
+'use strict';
+
+var path = require('path');
+var utils = require('../../lib/utils');
+
+describe('stackTraceFilter()', function () {
+  describe('on node', function () {
+    var filter = utils.stackTraceFilter();
+
+    describe('on POSIX OS', function () {
+      before(function () {
+        if (path.sep !== '/') {
+          this.skip();
+        }
+      });
+
+      it('should get a stack-trace as a string and prettify it', function () {
+        var stack = [
+          'AssertionError: foo bar',
+          'at EventEmitter.<anonymous> (/usr/local/dev/test.js:16:12)',
+          'at Context.<anonymous> (/usr/local/dev/test.js:19:5)',
+          'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)',
+          'Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)',
+          '/usr/local/lib/node_modules/mocha/lib/runner.js:452:12',
+          'next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)',
+          '/usr/local/lib/node_modules/mocha/lib/runner.js:309:7',
+          'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)',
+          'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)',
+          'at processImmediate [as _immediateCallback] (timers.js:321:17)'
+        ];
+        filter(stack.join('\n'))
+          .should
+          .equal(stack.slice(0, 3)
+            .join('\n'));
+
+        stack = [
+          'AssertionError: bar baz',
+          'at /usr/local/dev/some-test-file.js:25:8',
+          'at tryCatcher (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/util.js:24:31)',
+          'at Promise._resolveFromResolver (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:439:31)',
+          'at new Promise (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:53:37)',
+          'at yourFunction (/usr/local/dev/own/tmp/test1.js:24:13)',
+          'at Context.<anonymous> (/usr/local/dev/some-test-file:30:4)',
+          'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:218:15)',
+          'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)',
+          'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)',
+          'at processImmediate [as _immediateCallback] (timers.js:321:17)'
+        ];
+
+        filter(stack.join('\n'))
+          .should
+          .equal(stack.slice(0, 7)
+            .join('\n'));
+      });
+
+      it('does not ignore other bower_components and components', function () {
+        var stack = [
+          'Error: failed',
+          'at assert (index.html:11:26)',
+          'at Context.<anonymous> (test.js:17:18)',
+          'at bower_components/should/should.js:4827:7',
+          'at next (file:///.../bower_components/should/should.js:4766:23)',
+          'at components/should/5.0.0/should.js:4827:7',
+          'at next (file:///.../components/should/5.0.0/should.js:4766:23)',
+          'at file:///.../bower_components/mocha/mocha.js:4794:5',
+          'at timeslice (.../components/mocha/mocha.js:6218:27)',
+          'at Test.require.register.Runnable.run (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4463:15)',
+          'at Runner.require.register.Runner.runTest (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4892:10)',
+          'at file:///.../components/mochajs/mocha/2.1.0/mocha.js:4970:12',
+          'at next (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4817:14)'
+        ];
+        filter(stack.join('\n'))
+          .should
+          .equal(stack.slice(0, 7)
+            .join('\n'));
+      });
+
+      it('should replace absolute with relative paths', function () {
+        var stack = [
+          'Error: ' + process.cwd() + '/bla.js has a problem',
+          'at foo (' + process.cwd() + '/foo/index.js:13:226)',
+          'at bar (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:11:26)'
+        ];
+
+        var expected = [
+          'Error: ' + process.cwd() + '/bla.js has a problem',
+          'at foo (foo/index.js:13:226)',
+          'at bar (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:11:26)'
+        ];
+
+        filter(stack.join('\n'))
+          .should
+          .equal(expected.join('\n'));
+      });
+    });
+
+    describe('on Windows', function () {
+      before(function () {
+        if (path.sep === '/') {
+          this.skip();
+        }
+      });
+
+      it('should work on Windows', function () {
+        var stack = [
+          'Error: failed',
+          'at Context.<anonymous> (C:\\Users\\ishida\\src\\test\\test\\mytest.js:5:9)',
+          'at callFn (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runnable.js:326:21)',
+          'at Test.Runnable.run (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runnable.js:319:7)',
+          'at Runner.runTest (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:422:10)',
+          'at C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:528:12',
+          'at next (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:342:14)',
+          'at C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:352:7',
+          'at next (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:284:14)',
+          'at Immediate._onImmediate (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:320:5)'
+        ];
+        filter(stack.join('\n'))
+          .should
+          .equal(stack.slice(0, 2)
+            .join('\n'));
+      });
+    });
+  });
+
+  describe('on browser', function () {
+    var filter;
+    before(function () {
+      global.document = true;
+      global.location = {href: 'localhost:3000/foo/bar/index.html'};
+      filter = utils.stackTraceFilter();
+    });
+    it('does not strip out other bower_components', function () {
+      var stack = [
+        'Error: failed',
+        'at assert (index.html:11:26)',
+        'at Context.<anonymous> (test.js:17:18)',
+        'at bower_components/should/should.js:4827:7',
+        'at next (bower_components/should/should.js:4766:23)',
+        'at components/should/5.0.0/should.js:4827:7',
+        'at next (components/should/5.0.0/should.js:4766:23)',
+        'at Runner.require.register.Runner.runTest (node_modules/mocha.js:4892:10)',
+        'at localhost:3000/foo/bar/node_modules/mocha.js:4970:12',
+        'at next (node_modules/mocha.js:4817:14)'
+      ];
+      filter(stack.join('\n'))
+        .should
+        .equal(stack.slice(0, 7)
+          .join('\n'));
+    });
+
+    after(function () {
+      delete global.document;
+      delete global.location;
+    });
+  });
+});
diff --git a/test/acceptance/require/a.js b/test/require/a.js
similarity index 100%
rename from test/acceptance/require/a.js
rename to test/require/a.js
diff --git a/test/acceptance/require/b.coffee b/test/require/b.coffee
similarity index 100%
rename from test/acceptance/require/b.coffee
rename to test/require/b.coffee
diff --git a/test/acceptance/require/c.js b/test/require/c.js
similarity index 100%
rename from test/acceptance/require/c.js
rename to test/require/c.js
diff --git a/test/acceptance/require/d.coffee b/test/require/d.coffee
similarity index 100%
rename from test/acceptance/require/d.coffee
rename to test/require/d.coffee
diff --git a/test/acceptance/require/require.spec.js b/test/require/require.spec.js
similarity index 100%
rename from test/acceptance/require/require.spec.js
rename to test/require/require.spec.js
diff --git a/test/acceptance/context.spec.js b/test/unit/context.spec.js
similarity index 100%
rename from test/acceptance/context.spec.js
rename to test/unit/context.spec.js
diff --git a/test/acceptance/duration.spec.js b/test/unit/duration.spec.js
similarity index 100%
rename from test/acceptance/duration.spec.js
rename to test/unit/duration.spec.js
diff --git a/test/acceptance/globals.spec.js b/test/unit/globals.spec.js
similarity index 100%
rename from test/acceptance/globals.spec.js
rename to test/unit/globals.spec.js
diff --git a/test/grep.spec.js b/test/unit/grep.spec.js
similarity index 98%
rename from test/grep.spec.js
rename to test/unit/grep.spec.js
index dd21cf0090..bb620f9ba2 100644
--- a/test/grep.spec.js
+++ b/test/unit/grep.spec.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var Mocha = require('../');
+var Mocha = require('../../lib/mocha');
 
 describe('Mocha', function () {
   describe('"grep" option', function () {
diff --git a/test/hook-async.spec.js b/test/unit/hook-async.spec.js
similarity index 100%
rename from test/hook-async.spec.js
rename to test/unit/hook-async.spec.js
diff --git a/test/hook-sync-nested.spec.js b/test/unit/hook-sync-nested.spec.js
similarity index 100%
rename from test/hook-sync-nested.spec.js
rename to test/unit/hook-sync-nested.spec.js
diff --git a/test/hook-sync.spec.js b/test/unit/hook-sync.spec.js
similarity index 100%
rename from test/hook-sync.spec.js
rename to test/unit/hook-sync.spec.js
diff --git a/test/hook-timeout.spec.js b/test/unit/hook-timeout.spec.js
similarity index 100%
rename from test/hook-timeout.spec.js
rename to test/unit/hook-timeout.spec.js
diff --git a/test/mocha.spec.js b/test/unit/mocha.spec.js
similarity index 95%
rename from test/mocha.spec.js
rename to test/unit/mocha.spec.js
index 618742cdbd..af0c44a730 100644
--- a/test/mocha.spec.js
+++ b/test/unit/mocha.spec.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var Mocha = require('../');
+var Mocha = require('../../lib/mocha');
 var Test = Mocha.Test;
 
 describe('Mocha', function () {
diff --git a/test/ms.spec.js b/test/unit/ms.spec.js
similarity index 98%
rename from test/ms.spec.js
rename to test/unit/ms.spec.js
index 26f5c30209..6ceab5d409 100644
--- a/test/ms.spec.js
+++ b/test/unit/ms.spec.js
@@ -1,5 +1,5 @@
 'use strict';
-var ms = require('../lib/ms');
+var ms = require('../../lib/ms');
 
 describe('.ms()', function () {
   // Helpers
diff --git a/test/acceptance/overspecified-async.spec.js b/test/unit/overspecified-async.spec.js
similarity index 100%
rename from test/acceptance/overspecified-async.spec.js
rename to test/unit/overspecified-async.spec.js
diff --git a/test/acceptance/required-tokens.spec.js b/test/unit/required-tokens.spec.js
similarity index 100%
rename from test/acceptance/required-tokens.spec.js
rename to test/unit/required-tokens.spec.js
diff --git a/test/acceptance/root.spec.js b/test/unit/root.spec.js
similarity index 100%
rename from test/acceptance/root.spec.js
rename to test/unit/root.spec.js
diff --git a/test/runnable.spec.js b/test/unit/runnable.spec.js
similarity index 96%
rename from test/runnable.spec.js
rename to test/unit/runnable.spec.js
index 67cfcca38a..59bffff7be 100644
--- a/test/runnable.spec.js
+++ b/test/unit/runnable.spec.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var mocha = require('../');
+var mocha = require('../../lib/mocha');
 var utils = mocha.utils;
 var Runnable = mocha.Runnable;
 
@@ -183,7 +183,9 @@ describe('Runnable(title, fn)', function () {
     describe('when timeouts are disabled', function () {
       it('should not error with timeout', function (done) {
         var test = new Runnable('foo', function (done) {
-          setTimeout(process.nextTick.bind(undefined, done), 2);
+          setTimeout(function () {
+            setTimeout(done);
+          }, 2);
         });
         test.timeout(1);
         test.enableTimeouts(false);
@@ -195,7 +197,7 @@ describe('Runnable(title, fn)', function () {
       describe('without error', function () {
         it('should invoke the callback', function (done) {
           var test = new Runnable('foo', function (done) {
-            process.nextTick(done);
+            setTimeout(done);
           });
 
           test.run(done);
@@ -210,9 +212,9 @@ describe('Runnable(title, fn)', function () {
 
             var test = new Runnable('foo', function (done) {
               process.nextTick(done);
-              process.nextTick(done);
-              process.nextTick(done);
-              process.nextTick(done);
+              setTimeout(done);
+              setTimeout(done);
+              setTimeout(done);
             });
 
             test.on('error', function (err) {
@@ -236,10 +238,10 @@ describe('Runnable(title, fn)', function () {
 
             var test = new Runnable('foo', function (done) {
               done(new Error('fail'));
-              process.nextTick(done);
+              setTimeout(done);
               done(new Error('fail'));
-              process.nextTick(done);
-              process.nextTick(done);
+              setTimeout(done);
+              setTimeout(done);
             });
 
             test.on('error', function (err) {
@@ -359,7 +361,7 @@ describe('Runnable(title, fn)', function () {
       describe('when the promise is fulfilled with no value', function () {
         var fulfilledPromise = {
           then: function (fulfilled, rejected) {
-            process.nextTick(fulfilled);
+            setTimeout(fulfilled);
           }
         };
 
@@ -375,7 +377,7 @@ describe('Runnable(title, fn)', function () {
       describe('when the promise is fulfilled with a value', function () {
         var fulfilledPromise = {
           then: function (fulfilled, rejected) {
-            process.nextTick(function () {
+            setTimeout(function () {
               fulfilled({});
             });
           }
@@ -394,7 +396,7 @@ describe('Runnable(title, fn)', function () {
         var expectedErr = new Error('fail');
         var rejectedPromise = {
           then: function (fulfilled, rejected) {
-            process.nextTick(function () {
+            setTimeout(function () {
               rejected(expectedErr);
             });
           }
@@ -416,7 +418,7 @@ describe('Runnable(title, fn)', function () {
         var expectedErr = new Error('Promise rejected with no or falsy reason');
         var rejectedPromise = {
           then: function (fulfilled, rejected) {
-            process.nextTick(function () {
+            setTimeout(function () {
               rejected();
             });
           }
diff --git a/test/runner.spec.js b/test/unit/runner.spec.js
similarity index 99%
rename from test/runner.spec.js
rename to test/unit/runner.spec.js
index 7c69846ec8..c3dc379dfb 100644
--- a/test/runner.spec.js
+++ b/test/unit/runner.spec.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var mocha = require('../');
+var mocha = require('../../lib/mocha');
 var Suite = mocha.Suite;
 var Runner = mocha.Runner;
 var Test = mocha.Test;
diff --git a/test/suite.spec.js b/test/unit/suite.spec.js
similarity index 99%
rename from test/suite.spec.js
rename to test/unit/suite.spec.js
index 4cb62dd290..4233f957d6 100644
--- a/test/suite.spec.js
+++ b/test/unit/suite.spec.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var mocha = require('../');
+var mocha = require('../../lib/mocha');
 var Suite = mocha.Suite;
 var Test = mocha.Test;
 
diff --git a/test/test.spec.js b/test/unit/test.spec.js
similarity index 98%
rename from test/test.spec.js
rename to test/unit/test.spec.js
index 73c09b3b06..455cfe04ae 100644
--- a/test/test.spec.js
+++ b/test/unit/test.spec.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var mocha = require('../');
+var mocha = require('../../lib/mocha');
 var should = require('should');
 var Test = mocha.Test;
 
diff --git a/test/acceptance/throw.spec.js b/test/unit/throw.spec.js
similarity index 100%
rename from test/acceptance/throw.spec.js
rename to test/unit/throw.spec.js
diff --git a/test/acceptance/timeout.spec.js b/test/unit/timeout.spec.js
similarity index 100%
rename from test/acceptance/timeout.spec.js
rename to test/unit/timeout.spec.js
diff --git a/test/acceptance/utils.spec.js b/test/unit/utils.spec.js
similarity index 71%
rename from test/acceptance/utils.spec.js
rename to test/unit/utils.spec.js
index 545bdfd265..85b1950727 100644
--- a/test/acceptance/utils.spec.js
+++ b/test/unit/utils.spec.js
@@ -6,13 +6,80 @@ var JSON = require('json3');
 
 describe('lib/utils', function () {
   describe('clean', function () {
+    it('should remove the wrapping function declaration', function () {
+      utils.clean('function  (one, two, three)  {\n//code\n}')
+        .should
+        .equal('//code');
+    });
+
+    it('should handle newlines in the function declaration', function () {
+      utils.clean('function  (one, two, three)\n  {\n//code\n}')
+        .should
+        .equal('//code');
+    });
+
+    it('should remove space character indentation from the function body',
+      function () {
+        utils.clean('  //line1\n    //line2')
+          .should
+          .equal('//line1\n  //line2');
+      });
+
+    it('should remove tab character indentation from the function body',
+      function () {
+        utils.clean('\t//line1\n\t\t//line2')
+          .should
+          .equal('//line1\n\t//line2');
+      });
+
+    it('should handle functions with tabs in their declarations', function () {
+      utils.clean('function\t(\t)\t{\n//code\n}')
+        .should
+        .equal('//code');
+    });
+
+    it('should handle named functions without space after name', function () {
+      utils.clean('function withName() {\n//code\n}')
+        .should
+        .equal('//code');
+    });
+
+    it('should handle named functions with space after name', function () {
+      utils.clean('function withName () {\n//code\n}')
+        .should
+        .equal('//code');
+    });
+
+    it(
+      'should handle functions with no space between the end and the closing brace',
+      function () {
+        utils.clean('function() {/*code*/}')
+          .should
+          .equal('/*code*/');
+      });
+
+    it('should handle functions with parentheses in the same line',
+      function () {
+        utils.clean('function() { if (true) { /* code */ } }')
+          .should
+          .equal('if (true) { /* code */ }');
+      });
+
+    it('should handle empty functions', function () {
+      utils.clean('function() {}')
+        .should
+        .equal('');
+    });
+
     it('should format a single line test function', function () {
       var fn = [
         'function () {',
         '  var a = 1;',
         '}'
       ].join('\n');
-      expect(utils.clean(fn)).to.equal('var a = 1;');
+      expect(utils.clean(fn))
+        .to
+        .equal('var a = 1;');
     });
 
     it('should format a multi line test indented with spaces', function () {
@@ -23,7 +90,9 @@ describe('lib/utils', function () {
         '    var b = 2;',
         '  var c = 3;  }'
       ].join('\n');
-      expect(utils.clean(fn)).to.equal('var a = 1;\n  var b = 2;\nvar c = 3;');
+      expect(utils.clean(fn))
+        .to
+        .equal('var a = 1;\n  var b = 2;\nvar c = 3;');
     });
 
     it('should format a multi line test indented with tabs', function () {
@@ -34,7 +103,9 @@ describe('lib/utils', function () {
         '\t}',
         '}'
       ].join('\n');
-      expect(utils.clean(fn)).to.equal('if (true) {\n\tvar a = 1;\n}');
+      expect(utils.clean(fn))
+        .to
+        .equal('if (true) {\n\tvar a = 1;\n}');
     });
 
     it('should format functions saved in windows style - spaces', function () {
@@ -45,7 +116,9 @@ describe('lib/utils', function () {
         '   } while (false);',
         ' }'
       ].join('\r\n');
-      expect(utils.clean(fn)).to.equal('do {\n "nothing";\n} while (false);');
+      expect(utils.clean(fn))
+        .to
+        .equal('do {\n "nothing";\n} while (false);');
     });
 
     it('should format functions saved in windows style - tabs', function () {
@@ -58,7 +131,9 @@ describe('lib/utils', function () {
         '\t}',
         '}'
       ].join('\r\n');
-      expect(utils.clean(fn)).to.equal('if (false) {\n\tvar json = {\n\t\tone : 1\n\t};\n}');
+      expect(utils.clean(fn))
+        .to
+        .equal('if (false) {\n\tvar json = {\n\t\tone : 1\n\t};\n}');
     });
 
     it('should format es6 arrow functions', function () {
@@ -67,12 +142,16 @@ describe('lib/utils', function () {
         '  var a = 1;',
         '}'
       ].join('\n');
-      expect(utils.clean(fn)).to.equal('var a = 1;');
+      expect(utils.clean(fn))
+        .to
+        .equal('var a = 1;');
     });
 
     it('should format es6 arrow functions with implicit return', function () {
       var fn = '() => foo()';
-      expect(utils.clean(fn)).to.equal('foo()');
+      expect(utils.clean(fn))
+        .to
+        .equal('foo()');
     });
   });
 
@@ -415,4 +494,129 @@ describe('lib/utils', function () {
       Object.prototype.toString = toString;
     });
   });
+
+  describe('isBuffer()', function () {
+    var isBuffer = utils.isBuffer;
+    it('should test if object is a Buffer', function () {
+      isBuffer(new Buffer([0x01]))
+        .should
+        .equal(true);
+      isBuffer({})
+        .should
+        .equal(false);
+    });
+  });
+
+  describe('map()', function () {
+    var map = utils.map;
+    it('should behave same as Array.prototype.map', function () {
+      var arr = [
+        1,
+        2,
+        3
+      ];
+      map(arr, JSON.stringify)
+        .should
+        .eql(arr.map(JSON.stringify));
+    });
+
+    it('should call the callback with 3 arguments[currentValue, index, array]',
+      function () {
+        var index = 0;
+        map([
+          1,
+          2,
+          3
+        ], function (e, i, arr) {
+          e.should.equal(arr[index]);
+          i.should.equal(index++);
+        });
+      });
+
+    it('should apply with the given scope', function () {
+      var scope = {};
+      map([
+        'a',
+        'b',
+        'c'
+      ], function () {
+        this.should.equal(scope);
+      }, scope);
+    });
+  });
+
+  describe('some()', function () {
+    var some = utils.some;
+
+    it(
+      'should return true when some array elements pass the check of the fn parameter',
+      function () {
+        var result = some([
+          'a',
+          'b',
+          'c'
+        ], function (e) {
+          return e === 'b';
+        });
+        result.should.eql(true);
+      });
+
+    it(
+      'should return false when none of the array elements pass the check of the fn parameter',
+      function () {
+        var result = some([
+          'a',
+          'b',
+          'c'
+        ], function (e) {
+          return e === 'd';
+        });
+        result.should.eql(false);
+      });
+  });
+
+  describe('parseQuery()', function () {
+    var parseQuery = utils.parseQuery;
+    it('should get queryString and return key-value object', function () {
+      parseQuery('?foo=1&bar=2&baz=3')
+        .should
+        .eql({
+          foo: '1',
+          bar: '2',
+          baz: '3'
+        });
+
+      parseQuery('?r1=^@(?!.*\\)$)&r2=m{2}&r3=^co.*')
+        .should
+        .eql({
+          r1: '^@(?!.*\\)$)',
+          r2: 'm{2}',
+          r3: '^co.*'
+        });
+    });
+
+    it('should parse "+" as a space', function () {
+      parseQuery('?grep=foo+bar')
+        .should
+        .eql({grep: 'foo bar'});
+    });
+  });
+
+  describe('isPromise', function () {
+    it('should return true if the value is Promise-ish', function () {
+      utils.isPromise({
+        then: function () {
+        }
+      }).should.be.true;
+    });
+
+    it('should return false if the value is not an object', function () {
+      utils.isPromise(1).should.be.false;
+    });
+
+    it('should return false if the value is an object w/o a "then" function',
+      function () {
+        utils.isPromise({}).should.be.false;
+      });
+  });
 });
diff --git a/test/utils.spec.js b/test/utils.spec.js
deleted file mode 100644
index 2eaf908cd6..0000000000
--- a/test/utils.spec.js
+++ /dev/null
@@ -1,285 +0,0 @@
-'use strict';
-
-var mocha = require('..');
-var utils = mocha.utils;
-var path = require('path');
-var JSON = require('json3');
-
-describe('utils', function () {
-  describe('.clean()', function () {
-    var clean = utils.clean;
-    it('should remove the wrapping function declaration', function () {
-      clean('function  (one, two, three)  {\n//code\n}').should.equal('//code');
-    });
-
-    it('should handle newlines in the function declaration', function () {
-      clean('function  (one, two, three)\n  {\n//code\n}').should.equal('//code');
-    });
-
-    it('should remove space character indentation from the function body', function () {
-      clean('  //line1\n    //line2').should.equal('//line1\n  //line2');
-    });
-
-    it('should remove tab character indentation from the function body', function () {
-      clean('\t//line1\n\t\t//line2').should.equal('//line1\n\t//line2');
-    });
-
-    it('should handle functions with tabs in their declarations', function () {
-      clean('function\t(\t)\t{\n//code\n}').should.equal('//code');
-    });
-
-    it('should handle named functions without space after name', function () {
-      clean('function withName() {\n//code\n}').should.equal('//code');
-    });
-
-    it('should handle named functions with space after name', function () {
-      clean('function withName () {\n//code\n}').should.equal('//code');
-    });
-
-    it('should handle functions with no space between the end and the closing brace', function () {
-      clean('function() {/*code*/}').should.equal('/*code*/');
-    });
-
-    it('should handle functions with parentheses in the same line', function () {
-      clean('function() { if (true) { /* code */ } }').should.equal('if (true) { /* code */ }');
-    });
-
-    it('should handle empty functions', function () {
-      clean('function() {}').should.equal('');
-    });
-  });
-
-  describe('.isBuffer()', function () {
-    var isBuffer = utils.isBuffer;
-    it('should test if object is a Buffer', function () {
-      isBuffer(new Buffer([0x01])).should.equal(true);
-      isBuffer({}).should.equal(false);
-    });
-  });
-
-  describe('.map()', function () {
-    var map = utils.map;
-    it('should behave same as Array.prototype.map', function () {
-      var arr = [1, 2, 3];
-      map(arr, JSON.stringify).should.eql(arr.map(JSON.stringify));
-    });
-
-    it('should call the callback with 3 arguments[currentValue, index, array]', function () {
-      var index = 0;
-      map([1, 2, 3], function (e, i, arr) {
-        e.should.equal(arr[index]);
-        i.should.equal(index++);
-      });
-    });
-
-    it('should apply with the given scope', function () {
-      var scope = {};
-      map(['a', 'b', 'c'], function () {
-        this.should.equal(scope);
-      }, scope);
-    });
-  });
-
-  describe('.some()', function () {
-    var some = utils.some;
-
-    it('should return true when some array elements pass the check of the fn parameter', function () {
-      var result = some(['a', 'b', 'c'], function (e) {
-        return e === 'b';
-      });
-      result.should.eql(true);
-    });
-
-    it('should return false when none of the array elements pass the check of the fn parameter', function () {
-      var result = some(['a', 'b', 'c'], function (e) {
-        return e === 'd';
-      });
-      result.should.eql(false);
-    });
-  });
-
-  describe('.parseQuery()', function () {
-    var parseQuery = utils.parseQuery;
-    it('should get queryString and return key-value object', function () {
-      parseQuery('?foo=1&bar=2&baz=3').should.eql({
-        foo: '1',
-        bar: '2',
-        baz: '3'
-      });
-
-      parseQuery('?r1=^@(?!.*\\)$)&r2=m{2}&r3=^co.*').should.eql({
-        r1: '^@(?!.*\\)$)',
-        r2: 'm{2}',
-        r3: '^co.*'
-      });
-    });
-
-    it('should parse "+" as a space', function () {
-      parseQuery('?grep=foo+bar').should.eql({grep: 'foo bar'});
-    });
-  });
-
-  describe('.stackTraceFilter()', function () {
-    describe('on node', function () {
-      var filter = utils.stackTraceFilter();
-
-      describe('on POSIX OS', function () {
-        before(function () {
-          if (path.sep !== '/') {
-            this.skip();
-          }
-        });
-
-        it('should get a stack-trace as a string and prettify it', function () {
-          var stack = [
-            'AssertionError: foo bar',
-            'at EventEmitter.<anonymous> (/usr/local/dev/test.js:16:12)',
-            'at Context.<anonymous> (/usr/local/dev/test.js:19:5)',
-            'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)',
-            'Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)',
-            '/usr/local/lib/node_modules/mocha/lib/runner.js:452:12',
-            'next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)',
-            '/usr/local/lib/node_modules/mocha/lib/runner.js:309:7',
-            'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)',
-            'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)',
-            'at processImmediate [as _immediateCallback] (timers.js:321:17)'
-          ];
-          filter(stack.join('\n'))
-            .should
-            .equal(stack.slice(0, 3)
-              .join('\n'));
-
-          stack = [
-            'AssertionError: bar baz',
-            'at /usr/local/dev/some-test-file.js:25:8',
-            'at tryCatcher (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/util.js:24:31)',
-            'at Promise._resolveFromResolver (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:439:31)',
-            'at new Promise (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:53:37)',
-            'at yourFunction (/usr/local/dev/own/tmp/test1.js:24:13)',
-            'at Context.<anonymous> (/usr/local/dev/some-test-file:30:4)',
-            'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:218:15)',
-            'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)',
-            'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)',
-            'at processImmediate [as _immediateCallback] (timers.js:321:17)'
-          ];
-
-          filter(stack.join('\n'))
-            .should
-            .equal(stack.slice(0, 7)
-              .join('\n'));
-        });
-
-        it('does not ignore other bower_components and components',
-          function () {
-            var stack = [
-              'Error: failed',
-              'at assert (index.html:11:26)',
-              'at Context.<anonymous> (test.js:17:18)',
-              'at bower_components/should/should.js:4827:7',
-              'at next (file:///.../bower_components/should/should.js:4766:23)',
-              'at components/should/5.0.0/should.js:4827:7',
-              'at next (file:///.../components/should/5.0.0/should.js:4766:23)',
-              'at file:///.../bower_components/mocha/mocha.js:4794:5',
-              'at timeslice (.../components/mocha/mocha.js:6218:27)',
-              'at Test.require.register.Runnable.run (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4463:15)',
-              'at Runner.require.register.Runner.runTest (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4892:10)',
-              'at file:///.../components/mochajs/mocha/2.1.0/mocha.js:4970:12',
-              'at next (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4817:14)'
-            ];
-            filter(stack.join('\n'))
-              .should
-              .equal(stack.slice(0, 7)
-                .join('\n'));
-          });
-
-        it('should replace absolute with relative paths', function () {
-          var stack = [
-            'Error: ' + process.cwd() + '/bla.js has a problem',
-            'at foo (' + process.cwd() + '/foo/index.js:13:226)',
-            'at bar (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:11:26)'
-          ];
-
-          var expected = [
-            'Error: ' + process.cwd() + '/bla.js has a problem',
-            'at foo (foo/index.js:13:226)',
-            'at bar (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:11:26)'
-          ];
-
-          filter(stack.join('\n'))
-            .should
-            .equal(expected.join('\n'));
-        });
-      });
-
-      describe('on Windows', function () {
-        before(function () {
-          if (path.sep === '/') {
-            this.skip();
-          }
-        });
-
-        it('should work on Windows', function () {
-          var stack = [
-            'Error: failed',
-            'at Context.<anonymous> (C:\\Users\\ishida\\src\\test\\test\\mytest.js:5:9)',
-            'at callFn (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runnable.js:326:21)',
-            'at Test.Runnable.run (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runnable.js:319:7)',
-            'at Runner.runTest (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:422:10)',
-            'at C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:528:12',
-            'at next (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:342:14)',
-            'at C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:352:7',
-            'at next (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:284:14)',
-            'at Immediate._onImmediate (C:\\Users\\ishida\\src\\test\\node_modules\\mocha\\lib\\runner.js:320:5)'
-          ];
-          filter(stack.join('\n'))
-            .should
-            .equal(stack.slice(0, 2)
-              .join('\n'));
-        });
-      });
-    });
-
-    describe('on browser', function () {
-      var filter;
-      before(function () {
-        global.document = true;
-        global.location = { href: 'localhost:3000/foo/bar/index.html' };
-        filter = utils.stackTraceFilter();
-      });
-      it('does not strip out other bower_components', function () {
-        var stack = [
-          'Error: failed',
-          'at assert (index.html:11:26)',
-          'at Context.<anonymous> (test.js:17:18)',
-          'at bower_components/should/should.js:4827:7',
-          'at next (bower_components/should/should.js:4766:23)',
-          'at components/should/5.0.0/should.js:4827:7',
-          'at next (components/should/5.0.0/should.js:4766:23)',
-          'at Runner.require.register.Runner.runTest (node_modules/mocha.js:4892:10)',
-          'at localhost:3000/foo/bar/node_modules/mocha.js:4970:12',
-          'at next (node_modules/mocha.js:4817:14)'
-        ];
-        filter(stack.join('\n')).should.equal(stack.slice(0, 7).join('\n'));
-      });
-
-      after(function () {
-        delete global.document;
-        delete global.location;
-      });
-    });
-  });
-
-  describe('.isPromise', function () {
-    it('should return true if the value is Promise-ish', function () {
-      utils.isPromise({then: function () {}}).should.be.true;
-    });
-
-    it('should return false if the value is not an object', function () {
-      utils.isPromise(1).should.be.false;
-    });
-
-    it('should return false if the value is an object w/o a "then" function', function () {
-      utils.isPromise({}).should.be.false;
-    });
-  });
-});