diff --git a/go.mod b/go.mod
index 5d0b12f16..5ba52b036 100644
--- a/go.mod
+++ b/go.mod
@@ -48,6 +48,7 @@ require (
 	github.com/sergi/go-diff v1.0.0
 	github.com/smartystreets/goconvey v0.0.0-20190731233626-505e41936337
 	github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf // indirect
+	github.com/stretchr/testify v1.4.0
 	github.com/unknwon/cae v1.0.0
 	github.com/unknwon/com v1.0.1
 	github.com/unknwon/i18n v0.0.0-20190805065654-5c6446a380b6
diff --git a/go.sum b/go.sum
index 02ae9cf23..43fba3dbe 100644
--- a/go.sum
+++ b/go.sum
@@ -30,6 +30,7 @@ github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d h1:U+s90UTSY
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cupcake/rdb v0.0.0-20161107195141-43ba34106c76/go.mod h1:vYwsqCOLxGiisLwp9rITslkFNpZD5rz43tf41QFkTWY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/denisenkom/go-mssqldb v0.0.0-20190707035753-2be1aa521ff4/go.mod h1:zAg7JM8CkOJ43xKXIj7eRO9kmWm/TW578qo+oDO6tuM=
 github.com/denisenkom/go-mssqldb v0.0.0-20191001013358-cfbb681360f0 h1:epsH3lb7KVbXHYk7LYGN5EiE0MxcevHU85CKITJ0wUY=
@@ -179,6 +180,7 @@ github.com/pelletier/go-toml v1.4.0/go.mod h1:PN7xzY2wHTK0K9p34ErDQMlFxa51Fk0OUr
 github.com/pierrec/lz4 v2.0.5+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pquerna/otp v1.2.0 h1:/A3+Jn+cagqayeR3iHs/L62m5ue7710D35zl1zJ1kok=
 github.com/pquerna/otp v1.2.0/go.mod h1:dkJfzwRKNiegxyNb54X/3fLwhCynbMspSyWKnvi1AEg=
@@ -233,6 +235,7 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/syndtr/goleveldb v1.0.0/go.mod h1:ZVVdQEZoIme9iO1Ch2Jdy24qqXrMMOU6lpPAyBWyWuQ=
 github.com/unknwon/cae v1.0.0 h1:i39lOFaBXZxhGjQOy/RNbi8uzettCs6OQxpR0xXohGU=
@@ -344,6 +347,7 @@ gopkg.in/redis.v2 v2.3.2 h1:GPVIIB/JnL1wvfULefy3qXmPu1nfNu2d0yA09FHgwfs=
 gopkg.in/redis.v2 v2.3.2/go.mod h1:4wl9PJ/CqzeHk3LVq1hNLHH8krm3+AXEgut4jVc++LU=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
diff --git a/internal/osutil/osutil_test.go b/internal/osutil/osutil_test.go
new file mode 100644
index 000000000..adaebebf0
--- /dev/null
+++ b/internal/osutil/osutil_test.go
@@ -0,0 +1,34 @@
+// Copyright 2020 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package osutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsFile(t *testing.T) {
+	tests := []struct {
+		path   string
+		expVal bool
+	}{
+		{
+			path:   "osutil.go",
+			expVal: true,
+		}, {
+			path:   "../osutil",
+			expVal: false,
+		}, {
+			path:   "not_found",
+			expVal: false,
+		},
+	}
+	for _, test := range tests {
+		t.Run("", func(t *testing.T) {
+			assert.Equal(t, test.expVal, IsFile(test.path))
+		})
+	}
+}