Extract view logic to a view helper

app/helpers/measurements_helper.rb

@@ -2,4 +2,14 @@
 
 # Provides view helpers to MeasurementsController views.
 module MeasurementsHelper
+
+  def date_time_column_header
+    header = ''
+    if @measurements.any? { |m| m.approximate_time? }
+      header << content_tag(:span, '(≈ Approximate) ', :class => 'approximate')
+    end
+    header << 'Date/Time'
+    header
+  end
+
 end

app/views/measurements/_measurements.html.haml

@@ -4,10 +4,7 @@
   %thead
     %tr
       %th{'align' => 'right', 'valign' => 'bottom'}<
-        - if @measurements.any? { |m| m.approximate_time? }
-          %span.approximate<
-            (≈ Approximate)
-        Date/Time
+        = date_time_column_header
 
       %th{'align' => 'right', 'valign' => 'bottom'}<
         Adjusted Date

test/unit/helpers/measurements_helper_test.rb

@@ -1,4 +1,28 @@
 require 'test_helper'
 
-class MeasurementsHelperTest < ActionView::TestCase
+module MeasurementsHelperTest
+
+  class DateTimeColumnHeader < ActionView::TestCase
+
+    include MeasurementsHelper
+
+    test 'should return expected text when @measurements is empty' do
+      @measurements = []
+      assert_equal 'Date/Time', date_time_column_header
+    end
+
+    test 'should return expected text when @measurements contains no approximate times' do
+      @measurements = [stub(:approximate_time? => false)]
+      assert_equal 'Date/Time', date_time_column_header
+    end
+
+    test 'should return expected text when @measurements contains both an approximate time and an exact time' do
+      @measurements = [stub(:approximate_time? => true),
+                       stub(:approximate_time? => false)]
+      assert_equal '<span class="approximate">(≈ Approximate) </span>Date/Time',
+                   date_time_column_header
+    end
+
+  end
+
 end