Refactor Frame#compute_actual_size and add tests

lib/remedy/frame.rb

@@ -175,32 +175,46 @@ def compile_contents
       buffer.to_a
     end
 
-    def compute_actual_size merged_size
-      if size == :none then
-        frame.content_size
-      elsif size == :fill then
-        compile_size = available_size
-      elsif size == :auto then
-        compile_size = merged_size
-      elsif Tuple === size then
-        compile_size = size.dup
+    # Determine what the actual output size would be based on the size option and contents.
+    #
+    # Most of the time the output size can be determined statically based on the available
+    #   size information and the one parameter.
+    #
+    # In practice `:none` and `:auto` output the same maximum height and width - despite rendering differences.
+    #   Technically, `:none` will always result in `content_size`,
+    #   while `:auto` could in theory be further modified by the alignment and later processing.
+    #
+    # @parram arranged_size [Remedy::Tuple] an externally determined size after preprocessing
+    # @return [Remedy::Tuple] output size in rows/height and columns/width
+    def compute_actual_size arranged_size = content_size
+      case size
+      when :none
+        # generally identical to `arranged_size`
+        # if needed, using that here could save processing
+        content_size
+      when :fill
+        available_size
+      when :auto
+        arranged_size
+      when Tuple
+        actual_size = size.dup
 
         if size.height == 0 then
-          compile_size[0] = available_size.height
+          actual_size[0] = available_size.height
         elsif size.height < 1 then
-          compile_size[0] = (available_size.height * size.height).floor
+          actual_size[0] = (available_size.height * size.height).floor
         end
 
         if size.width == 0 then
-          compile_size[1] = available_size.width
+          actual_size[1] = available_size.width
         elsif size.width < 1 then
-          compile_size[1] = (available_size.width * size.width).floor
+          actual_size[1] = (available_size.width * size.width).floor
         end
+
+        actual_size
       else
         raise "Unknown max_size:#{size}"
       end
-
-      compile_size
     end
 
     def compute_horizontal_offset original_size, actual_size

spec/frame_spec.rb

@@ -50,6 +50,39 @@
     end
   end
 
+  describe "#compute_actual_size" do
+    it "returns a Tuple of the rendered size" do
+      f << "1234"
+      f << "567"
+      arranged_size = Tuple(5, 5)
+
+      f.size = :none
+      expected = Tuple 2, 4
+      actual = f.compute_actual_size arranged_size
+      expect(actual).to eq expected
+
+      f.size = :fill
+      actual = f.compute_actual_size arranged_size
+      expect(actual).to eq console_size
+
+      f.size = :auto
+      actual = f.compute_actual_size arranged_size
+      expect(actual).to eq arranged_size
+
+      f.size = sizeclass.zero
+      actual = f.compute_actual_size arranged_size
+      expect(actual).to eq console_size
+
+      f.size = sizeclass.new 2, 2
+      actual = f.compute_actual_size arranged_size
+      expect(actual).to eq sizeclass.new(2, 2)
+
+      f.size = sizeclass.new 0.5, 0.74
+      actual = f.compute_actual_size arranged_size
+      expect(actual).to eq sizeclass.new(10, 29)
+    end
+  end
+
   describe "#to_s" do
     it "returns a string" do
       expected = String