diff --git a/.busted b/.busted
new file mode 100644
index 000000000..4343ab3d9
--- /dev/null
+++ b/.busted
@@ -0,0 +1,6 @@
+return {
+	default = {
+		verbose = true,
+		ROOT = "spec/front/unit",
+	},
+}
diff --git a/.gitignore b/.gitignore
index 6aabe7d43..e4a04a2d8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@ git-rev
 tags
 test/*
 *.tar
+spec/unit/data
 
 emu
 
diff --git a/Makefile b/Makefile
index 1af9ad9ca..320f765db 100644
--- a/Makefile
+++ b/Makefile
@@ -38,6 +38,11 @@ endif
 	for f in $(INSTALL_FILES); do \
 		ln -sf ../../$$f $(INSTALL_DIR)/koreader/; \
 	done
+	# install front spec
+	cd $(INSTALL_DIR)/koreader/spec && test -e front || \
+		ln -sf ../../../../spec ./front
+	cd $(INSTALL_DIR)/koreader/spec/front/unit && test -e data || \
+		ln -sf ../../test ./data
 	# install plugins
 	cp -r plugins/* $(INSTALL_DIR)/koreader/plugins/
 	cp -rpL resources/fonts/* $(INSTALL_DIR)/koreader/fonts/
@@ -54,8 +59,16 @@ endif
 $(KOR_BASE)/$(OUTPUT_DIR)/luajit:
 	$(MAKE) -C $(KOR_BASE)
 
+$(INSTALL_DIR)/koreader/.busted:
+	test -e $(INSTALL_DIR)/koreader/.busted || \
+		ln -sf ../../.busted $(INSTALL_DIR)/koreader
+
+testfront: $(INSTALL_DIR)/koreader/.busted
+	cd $(INSTALL_DIR)/koreader && busted -l ./luajit
+
 test:
 	$(MAKE) -C $(KOR_BASE) test
+	$(MAKE) testfront
 
 .PHONY: test
 
diff --git a/frontend/ui/device.lua b/frontend/ui/device.lua
index 735b6ec43..2526b50c3 100644
--- a/frontend/ui/device.lua
+++ b/frontend/ui/device.lua
@@ -2,7 +2,7 @@ local KindlePowerD = require("ui/device/kindlepowerd")
 local KoboPowerD = require("ui/device/kobopowerd")
 local BasePowerD = require("ui/device/basepowerd")
 local Screen = require("ui/device/screen")
--- util
+local util = require("ffi/util")
 -- lfs
 
 local Device = {
diff --git a/spec/unit/document_spec.lua b/spec/unit/document_spec.lua
new file mode 100644
index 000000000..73ed68895
--- /dev/null
+++ b/spec/unit/document_spec.lua
@@ -0,0 +1,62 @@
+require "defaults"
+require "libs/libkoreader-luagettext"
+package.path = "?.lua;common/?.lua;frontend/?.lua"
+package.cpath = "?.so;common/?.so;/usr/lib/lua/?.so"
+
+-- global einkfb for Screen
+einkfb = require("ffi/framebuffer")
+-- do not show SDL window
+einkfb.dummy = true
+
+local Screen = require("ui/screen")
+local DocSettings = require("docsettings")
+G_reader_settings = DocSettings:open(".reader")
+local DocumentRegistry = require("document/documentregistry")
+local DEBUG = require("dbg")
+
+-- screen should be inited for crengine
+Screen:init()
+
+describe("PDF document module", function()
+    local sample_pdf = "spec/front/unit/data/tall.pdf"
+    it("should open document", function()
+        doc = DocumentRegistry:openDocument(sample_pdf)
+        assert.truthy(doc)
+    end)
+    it("should get page dimensions", function()
+        local dimen = doc:getPageDimensions(1, 1, 0)
+        assert.are.same(dimen.w, 567)
+        assert.are.same(dimen.h, 1418)
+    end)
+    local pos0 = {page = 1, x = 0, y = 20}
+    local pos1 = {page = 1, x = 300, y = 120}
+    local pboxes = {
+        {x = 26, y = 42, w = 240, h = 22},
+        {x = 48, y = 82, w = 185, h = 22},
+    }
+    it("should clip page rect to PNG file", function()
+        doc:clipPagePNGFile(pos0, pos1, nil, nil, "/tmp/clip0.png")
+        doc:clipPagePNGFile(pos0, pos1, pboxes, "lighten", "/tmp/clip1.png")
+    end)
+    it("should clip page rect to PNG string", function()
+        local clip0 = doc:clipPagePNGString(pos0, pos1, nil, nil)
+        assert.truthy(clip0)
+        local clip1 = doc:clipPagePNGString(pos0, pos1, pboxes, "lighten")
+        assert.truthy(clip1)
+    end)
+    it("should close document", function()
+        doc:close()
+    end)
+end)
+
+describe("EPUB document module", function()
+    local sample_epub = "spec/front/unit/data/leaves_of_grass.epub"
+    it("should open document", function()
+        doc = DocumentRegistry:openDocument(sample_epub)
+        assert.truthy(doc)
+        doc:close()
+    end)
+    it("should close document", function()
+        doc:close()
+    end)
+end)