Made specs better for issue prawnpdf#169 fix.

lib/prawn/text/formatted/box.rb

@@ -161,7 +161,7 @@ def initialize(formatted_text, options={})
           @align             = options[:align] ||
                                (@direction == :rtl ? :right : :left)
           @vertical_align    = options[:valign] || :top
-          @final_gap         = options[:final_gap].nil? || false
+          @final_gap         = options[:final_gap].nil? || options[:final_gap]
           @leading           = options[:leading] || @document.default_leading
           @character_spacing = options[:character_spacing] ||
                                @document.character_spacing
@@ -485,14 +485,15 @@ def process_vertical_alignment(text)
           @vertical_alignment_processed = true
 
           return if @vertical_align == :top
+
           wrap(text)
 
           case @vertical_align
           when :center
-            @at[1] = @at[1] - (@height - height + @descender) * 0.5
+            @at[1] -= (@height - height + @descender) * 0.5
           when :bottom
-            @at[1] = @at[1] - (@height - height) + @descender
-            @at[1] -= line_gap unless @final_gap
+            @at[1] -= (@height - height)
+            @at[1] += line_gap if @final_gap
           end
 
           @height = height

spec/formatted_text_box_spec.rb

@@ -619,53 +619,67 @@
 describe "Text::Formatted::Box#render with :valign => :center" do
   it "should have a bottom gap equal to baseline and bottom of box" do
     create_pdf
+    box_height = 100
+    y = 450
     array = [{ :text => 'Vertical Align' }]
     options = {
      :document => @pdf,
      :valign => :center,
-     :at => [0,450],
+     :at => [0,y],
      :width => 100,
-     :height => 100,
+     :height => box_height,
      :size => 16
     }
     text_box = Prawn::Text::Formatted::Box.new(array, options)
     text_box.render
-    text_box.at[1].should eq(405.744)
+    line_padding = (box_height - text_box.height + text_box.descender) * 0.5
+    baseline = y - line_padding
+
+    text_box.at[1].should be_within(0.01).of(baseline)
   end
 end
 
 describe "Text::Formatted::Box#render with :valign => :bottom" do
   it "should render a :final_gap on the bottom by default" do
     create_pdf
+    box_height = 100
+    y = 450
     array = [{ :text => 'Vertical Align' }]
     options = {
      :document => @pdf,
      :valign => :bottom,
-     :at => [0,450],
+     :at => [0,y],
      :width => 100,
-     :height => 100,
+     :height => box_height,
      :size => 16
     }
     text_box = Prawn::Text::Formatted::Box.new(array, options)
     text_box.render
-    text_box.at[1].should eq(368.112)
+    top_padding = y - (box_height - text_box.height)
+    top_padding += text_box.line_gap
+
+    text_box.at[1].should be_within(0.01).of(top_padding)
   end
 
   it "should not render a :final_gap if set to false" do
     create_pdf
+    box_height = 100
+    y = 450
     array = [{ :text => 'Vertical Align' }]
     options = {
      :document => @pdf,
      :valign => :bottom,
      :final_gap => false,
-     :at => [0,450],
+     :at => [0,y],
      :width => 100,
-     :height => 100,
+     :height => box_height,
      :size => 16
     }
     text_box = Prawn::Text::Formatted::Box.new(array, options)
     text_box.render
-    text_box.at[1].should eq(364.416)
+    top_padding = y - (box_height - text_box.height)
+
+    text_box.at[1].should be_within(0.01).of(top_padding)
   end
 end