Added Size module

spec/unit/size_spec.lua

@@ -0,0 +1,31 @@
+describe("Size module", function()
+    local Size
+    setup(function()
+        require("commonrequire")
+        Size = require("ui/size")
+    end)
+    describe("should get size", function()
+        it("for window border", function()
+            assert.is_true(Size.border.window >= 1)
+        end)
+    end)
+    it("should be nil for non-existent property", function()
+        assert.is_nil(Size.supercalifragilisticexpialidocious)
+        assert.is_nil(Size.border.supercalifragilisticexpialidocious)
+    end)
+    it("should fail for non-existent property when debug is activated", function()
+        local dbg = require("dbg")
+        dbg:turnOn()
+        Size = package.reload("ui/size")
+        local supercalifragilisticexpialidocious1 = function()
+            return Size.supercalifragilisticexpialidocious
+        end
+        local supercalifragilisticexpialidocious2 = function()
+            return Size.border.supercalifragilisticexpialidocious
+        end
+
+        assert.has_error(supercalifragilisticexpialidocious1, "Size: this property does not exist: Size.supercalifragilisticexpialidocious")
+        assert.has_error(supercalifragilisticexpialidocious2, "Size: this property does not exist: Size.border.supercalifragilisticexpialidocious")
+        dbg:turnOff()
+    end)
+end)