Added prev and next bounds checking.

README.md

@@ -24,7 +24,7 @@ gem 'lita-garfield'
 !garfield first - Get the first garfield comic.
 !garfield last - Get the last garfield comic.
 !garfield today - Get today's garfield comic.
-!garfield prev - Get the previous day's comic based on the last one you displayed.*
-!garfield next - Get the next day's comic based on the last on you displayed.*
+!garfield prev - Get the previous day's comic based on the last one you displayed.
+!garfield next - Get the next day's comic based on the last on you displayed.
 
 * Coming soon to a Lita handler near you.

lib/lita/handlers/garfield.rb

@@ -71,12 +71,18 @@ def handle_mdy_garfield(response)
 
       def handle_next_garfield(response)
         date = Date.parse redis.get(response.user.name)
-        response.reply get_garfield_for_date(date + 1, response.user.name)
+        unless date == Date.today
+          date += 1
+        end
+        response.reply get_garfield_for_date(date, response.user.name)
       end
 
       def handle_prev_garfield(response)
         date = Date.parse redis.get(response.user.name)
-        response.reply get_garfield_for_date(date - 1, response.user.name)
+        unless date == Date.civil(1978, 6, 19)
+          date -= 1
+        end
+        response.reply get_garfield_for_date(date, response.user.name)
       end
     end
 

spec/lita/handlers/garfield_spec.rb

@@ -69,12 +69,28 @@ def get_todays_image_filename
   end
 
   # Test the saved state of the last comic you requested.
-  it 'will return the first and then the next garfield comic' do
+  it 'will return the first and then the next and then the previous garfield comic' do
     send_message '!garfield first'
     expect(replies.last).to include('https://garfield.com/uploads/strips/1978-06-19.jpg')
     send_message '!garfield next'
     expect(replies.last).to include('https://garfield.com/uploads/strips/1978-06-20.jpg')
     send_message '!garfield prev'
     expect(replies.last).to include('https://garfield.com/uploads/strips/1978-06-19.jpg')
   end
+
+  it 'will edge case prev and next' do
+    today = Date.today
+
+    first = 'https://garfield.com/uploads/strips/1978-06-19.jpg'
+    last = "https://garfield.com/uploads/strips/#{today.year}-#{zero_prefix today.month}-#{zero_prefix today.day}.jpg"
+
+    send_message '!garfield first'
+    expect(replies.last).to include(first)
+    send_message '!garfield prev'
+    expect(replies.last).to include(first)
+    send_message '!garfield last'
+    expect(replies.last).to include(last)
+    send_message '!garfield next'
+    expect(replies.last).to include(last)
+  end
 end