Refactor and migrate more functions out of api into app package (#5063)

app/file_test.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2017 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"testing"
+
+	"github.com/mattermost/platform/model"
+)
+
+func TestGeneratePublicLinkHash(t *testing.T) {
+	filename1 := model.NewId() + "/" + model.NewRandomString(16) + ".txt"
+	filename2 := model.NewId() + "/" + model.NewRandomString(16) + ".txt"
+	salt1 := model.NewRandomString(32)
+	salt2 := model.NewRandomString(32)
+
+	hash1 := GeneratePublicLinkHash(filename1, salt1)
+	hash2 := GeneratePublicLinkHash(filename2, salt1)
+	hash3 := GeneratePublicLinkHash(filename1, salt2)
+
+	if hash1 != GeneratePublicLinkHash(filename1, salt1) {
+		t.Fatal("hash should be equal for the same file name and salt")
+	}
+
+	if hash1 == hash2 {
+		t.Fatal("hashes for different files should not be equal")
+	}
+
+	if hash1 == hash3 {
+		t.Fatal("hashes for the same file with different salts should not be equal")
+	}
+}