Fix data races in tests, closes #255

Signed-off-by: Alexei Dodon <adodon@cisco.com>

pkg/storage/storage_fs.go

@@ -62,16 +62,7 @@ func (is *ImageStoreFS) RootDir() string {
 }
 
 func (is *ImageStoreFS) DirExists(d string) bool {
-	fi, err := os.Stat(d)
-	if err != nil && os.IsNotExist(err) {
-		return false
-	}
-
-	if !fi.IsDir() {
-		return false
-	}
-
-	return true
+	return DirExists(d)
 }
 
 func getRoutePrefix(name string) string {
@@ -1341,3 +1332,16 @@ func ifOlderThan(is *ImageStoreFS, repo string, delay time.Duration) casext.GCPo
 		return true, nil
 	}
 }
+
+func DirExists(d string) bool {
+	fi, err := os.Stat(d)
+	if err != nil && os.IsNotExist(err) {
+		return false
+	}
+
+	if !fi.IsDir() {
+		return false
+	}
+
+	return true
+}

pkg/storage/storage_fs_test.go

@@ -595,7 +595,7 @@ func TestNegativeCases(t *testing.T) {
 		So(err, ShouldNotBeNil)
 	})
 
-	Convey("Invalid dedupe sceanrios", t, func() {
+	Convey("Invalid dedupe scenarios", t, func() {
 		dir, err := ioutil.TempDir("", "oci-repo-test")
 		if err != nil {
 			panic(err)
@@ -671,6 +671,23 @@ func TestNegativeCases(t *testing.T) {
 		So(err, ShouldBeNil)
 		So(b, ShouldEqual, l)
 	})
+
+	Convey("DirExists call with a filename as argument", t, func(c C) {
+		dir, err := ioutil.TempDir("", "oci-repo-test")
+		if err != nil {
+			panic(err)
+		}
+		defer os.RemoveAll(dir)
+
+		filePath := path.Join(dir, "file.txt")
+		err = ioutil.WriteFile(filePath, []byte("some dummy file content"), 0644) //nolint: gosec
+		if err != nil {
+			panic(err)
+		}
+
+		ok := storage.DirExists(filePath)
+		So(ok, ShouldBeFalse)
+	})
 }
 
 func TestHardLink(t *testing.T) {

pkg/storage/storage_test.go

@@ -475,6 +475,15 @@ func TestStorageAPIs(t *testing.T) {
 							indexContent, err := il.GetIndexContent("test")
 							So(err, ShouldBeNil)
 
+							if testcase.storageType == "fs" {
+								err = os.Chmod(path.Join(il.RootDir(), "test", "index.json"), 0000)
+								So(err, ShouldBeNil)
+								_, err = il.GetIndexContent("test")
+								So(err, ShouldNotBeNil)
+								err = os.Chmod(path.Join(il.RootDir(), "test", "index.json"), 0644)
+								So(err, ShouldBeNil)
+							}
+
 							var index ispec.Index
 
 							err = json.Unmarshal(indexContent, &index)