test: add imagewidget_spec

spec/unit/imagewidget_spec.lua

@@ -0,0 +1,20 @@
+require("commonrequire")
+local ImageWidget = require("ui/widget/imagewidget")
+
+describe("ImageWidget module", function()
+    it("should render without error", function()
+        local imgw = ImageWidget:new{
+            file = "resources/icons/appbar.chevron.up.png"
+        }
+        imgw:_render()
+        assert(imgw._bb)
+    end)
+    it("should error out on none exist image", function()
+        local imgw = ImageWidget:new{
+            file = "wtf.png"
+        }
+        assert.has_error(function()
+            imgw:_render()
+        end)
+    end)
+end)

spec/unit/readerui_spec.lua

@@ -3,7 +3,6 @@ local DocumentRegistry = require("document/documentregistry")
 local ReaderUI = require("apps/reader/readerui")
 local DocSettings = require("docsettings")
 local UIManager = require("ui/uimanager")
-local DEBUG = require("dbg")
 
 describe("Readerui module", function()
     local sample_epub = "spec/front/unit/data/leaves.epub"