diff --git a/.travis.yml b/.travis.yml
index 2e3480a..a05fbbd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,10 @@
 sudo: required
-
+language: go
+install:
+  # Add Godeps dependencies to GOPATH and PATH
+  - export GOPATH="${TRAVIS_BUILD_DIR}/Godeps/_workspace:$GOPATH"
+  - export PATH="${TRAVIS_BUILD_DIR}/Godeps/_workspace/bin:$PATH"
 services:
   - docker
-
 script:
   - make test
diff --git a/Makefile b/Makefile
index 87249d9..12230de 100644
--- a/Makefile
+++ b/Makefile
@@ -25,9 +25,8 @@ ifneq (${DOCKER},)
 endif
 
 .PHONY: test
-test: test-plugin
+test: clean test-plugin
 
-# TODO: add unit tests
 test-unit:
 	go test ${TEST_FLAGS} -coverprofile=coverage
 
diff --git a/project.go b/project.go
index 2951aa1..c0ba435 100644
--- a/project.go
+++ b/project.go
@@ -7,6 +7,13 @@ import (
 	"strings"
 )
 
+func Min(x, y int) int {
+	if x < y {
+		return x
+	}
+	return y
+}
+
 // https://github.com/go-yaml/yaml/issues/100
 type StringArray []string
 
@@ -54,11 +61,8 @@ func (p *Project) checkAffected(changedFiles []string) bool {
 		normalizedPath := path.Clean(filePath)
 		projectDirs := strings.Split(normalizedPath, "/")
 		for _, changedFile := range changedFiles {
-			if changedFile == "" {
-				continue
-			}
 			changedDirs := strings.Split(changedFile, "/")
-			if reflect.DeepEqual(changedDirs[:len(projectDirs)], projectDirs) {
+			if reflect.DeepEqual(changedDirs[:Min(len(projectDirs), len(changedDirs))], projectDirs) {
 				return true
 			}
 		}
diff --git a/project_test.go b/project_test.go
new file mode 100644
index 0000000..8a88703
--- /dev/null
+++ b/project_test.go
@@ -0,0 +1,26 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCheckAffected(t *testing.T) {
+	assert := assert.New(t)
+
+	changedFiles := []string{"project1/app.py", "project2/README.md", "", "README.md"}
+
+	p1 := Project{Label: "project1", Path: []string{"project1/"}, Skip: []string{}}
+	assert.Equal(true, p1.checkAffected(changedFiles))
+
+	p2 := Project{Label: "project2", Path: []string{"project2"}, Skip: []string{"somelabel"}}
+	assert.Equal(true, p2.checkAffected(changedFiles))
+
+	p3 := Project{Label: "project3", Path: []string{"project3/", "project2/foo/"}, Skip: []string{"project1"}}
+	assert.Equal(false, p3.checkAffected(changedFiles))
+
+	// test no changes
+	assert.Equal(false, p3.checkAffected([]string{}))
+
+}