diff --git a/pkg/resource/files_test.go b/pkg/resource/files_test.go
new file mode 100644
index 0000000..9aa38d2
--- /dev/null
+++ b/pkg/resource/files_test.go
@@ -0,0 +1,89 @@
+package resource
+
+import (
+	"os"
+	"testing"
+	"time"
+)
+
+type MockFileInfo struct {
+	fileName string
+}
+
+func NewMockFileInfo(filename string) *MockFileInfo {
+	return &MockFileInfo{fileName: filename}
+}
+func (m *MockFileInfo) Name() string       { return m.fileName }
+func (m *MockFileInfo) Size() int64        { return 0 }           // length in bytes for regular files; system-dependent for others
+func (m *MockFileInfo) Mode() os.FileMode  { return 0 }           // file mode bits
+func (m *MockFileInfo) ModTime() time.Time { return time.Time{} } // modification time
+func (m *MockFileInfo) IsDir() bool        { return false }       // abbreviation for Mode().IsDir()
+func (m *MockFileInfo) Sys() interface{}   { return nil }         // underlying data source (can return nil)
+
+func TestIsYamlFile(t *testing.T) {
+	for i, testCase := range []struct {
+		filename string
+		expect   bool
+	}{
+		{
+			"file.yaml",
+			true,
+		},
+		{
+			"/path/to/my/file.yaml",
+			true,
+		},
+		{
+			"file.yml",
+			true,
+		},
+		{
+			"/path/to/my/file.yml",
+			true,
+		},
+		{
+			"file.notyaml",
+			false,
+		},
+		{
+			"/path/to/my/file.notyaml",
+			false,
+		},
+		{
+			"/path/to/my/file",
+			false,
+		},
+	} {
+		if got := isYAMLFile(NewMockFileInfo(testCase.filename)); got != testCase.expect {
+			t.Errorf("test %d: for filename %s, expected %t, got %t", i+1, testCase.filename, testCase.expect, got)
+		}
+	}
+}
+
+func TestIsJSONFile(t *testing.T) {
+	for i, testCase := range []struct {
+		filename string
+		expect   bool
+	}{
+		{
+			"file.json",
+			true,
+		},
+		{
+			"/path/to/my/file.json",
+			true,
+		},
+		{
+			"file.notjson",
+			false,
+		},
+		{
+			"/path/to/my/file",
+			false,
+		},
+	} {
+		if got := isJSONFile(NewMockFileInfo(testCase.filename)); got != testCase.expect {
+			t.Errorf("test %d: for filename %s, expected %t, got %t", i+1, testCase.filename, testCase.expect, got)
+		}
+	}
+}
diff --git a/pkg/resource/resource_test.go b/pkg/resource/resource_test.go
index 6093e89..42fbec3 100644
--- a/pkg/resource/resource_test.go
+++ b/pkg/resource/resource_test.go
@@ -1,12 +1,13 @@
 package resource_test
 
 import (
-	"fmt"
 	"log"
+	"reflect"
 	"testing"
 
-	"github.com/yannh/kubeconform/pkg/resource"
 	"sigs.k8s.io/yaml"
+
+	"github.com/yannh/kubeconform/pkg/resource"
 )
 
 func TestSignatureFromBytes(t *testing.T) {
@@ -54,13 +55,20 @@ spec:
 func TestSignatureFromMap(t *testing.T) {
 	testCases := []struct {
 		b string
+		s resource.Signature
 	}{
 		{
 			"apiVersion: v1\nkind: ReplicationController\nmetadata:\n  name: \"bob\"\nspec:\n  replicas: 2\n",
+			resource.Signature{
+				Kind:      "ReplicationController",
+				Version:   "v1",
+				Namespace: "",
+				Name:      "bob",
+			},
 		},
 	}
 
-	for _, testCase := range testCases {
+	for i, testCase := range testCases {
 		res := resource.Resource{
 			Path:  "foo",
 			Bytes: []byte(testCase.b),
@@ -73,6 +81,8 @@ func TestSignatureFromMap(t *testing.T) {
 
 		res.SignatureFromMap(r)
 		sig, _ := res.Signature()
-		fmt.Printf("%+v", sig)
+		if !reflect.DeepEqual(*sig, testCase.s) {
+			t.Errorf("test %d - for resource %s, expected %+v, got %+v", i+1, testCase.b, testCase.s, sig)
+		}
 	}
 }