From b8b28e8c51606a7a606cb66a048b13ac7bd2d2fd Mon Sep 17 00:00:00 2001
From: Chris Hunt <chrishunt@github.com>
Date: Fri, 6 Jun 2014 08:59:42 -0700
Subject: [PATCH 1/2] Extract OSX::Database and test it

---
 lib/desktop.rb                     |  3 ++-
 lib/desktop/osx/database.rb        | 36 ++++++++++++++++++++++++++++++
 lib/desktop/{ => osx}/osx.rb       | 11 +++------
 test/desktop/osx/database_test.rb  | 28 +++++++++++++++++++++++
 test/desktop/{ => osx}/osx_test.rb |  2 +-
 5 files changed, 70 insertions(+), 10 deletions(-)
 create mode 100644 lib/desktop/osx/database.rb
 rename lib/desktop/{ => osx}/osx.rb (86%)
 create mode 100644 test/desktop/osx/database_test.rb
 rename test/desktop/{ => osx}/osx_test.rb (97%)

diff --git a/lib/desktop.rb b/lib/desktop.rb
index fa0af10..427b3a6 100644
--- a/lib/desktop.rb
+++ b/lib/desktop.rb
@@ -1,5 +1,6 @@
 require 'desktop/cli'
 require 'desktop/local_image'
-require 'desktop/osx'
 require 'desktop/version'
 require 'desktop/web_image'
+
+require 'desktop/osx/osx'
diff --git a/lib/desktop/osx/database.rb b/lib/desktop/osx/database.rb
new file mode 100644
index 0000000..053f131
--- /dev/null
+++ b/lib/desktop/osx/database.rb
@@ -0,0 +1,36 @@
+require 'sqlite3'
+
+module Desktop
+  class OSX
+    class Database
+      attr_reader :connection
+
+      def initialize(connection = nil)
+        @connection = connection || default_connection
+      end
+
+      def clear_desktop_image
+        clear_data
+      end
+
+      def close
+        connection.close
+      end
+
+      private
+
+      def clear_data
+        connection.execute 'DELETE FROM data'
+        connection.execute 'VACUUM data'
+      end
+
+      def default_connection
+        SQLite3::Database.new path
+      end
+
+      def path
+        File.expand_path '~/Library/Application Support/Dock/desktoppicture.db'
+      end
+    end
+  end
+end
diff --git a/lib/desktop/osx.rb b/lib/desktop/osx/osx.rb
similarity index 86%
rename from lib/desktop/osx.rb
rename to lib/desktop/osx/osx.rb
index b9598ba..cd4116a 100644
--- a/lib/desktop/osx.rb
+++ b/lib/desktop/osx/osx.rb
@@ -1,4 +1,4 @@
-require 'sqlite3'
+require 'desktop/osx/database'
 
 module Desktop
   class OSX
@@ -58,9 +58,8 @@ def write_default_desktop(image)
     end
 
     def clear_custom_desktop_image
-      db = SQLite3::Database.new(desktop_image_db_path)
-      db.execute 'DELETE FROM data'
-      db.execute 'VACUUM data'
+      db = Database.new
+      db.clear_desktop_image
       db.close
     end
 
@@ -71,9 +70,5 @@ def reload_desktop
     def default_desktop_image_path
       '/System/Library/CoreServices/DefaultDesktop.jpg'
     end
-
-    def desktop_image_db_path
-      File.expand_path '~/Library/Application Support/Dock/desktoppicture.db'
-    end
   end
 end
diff --git a/test/desktop/osx/database_test.rb b/test/desktop/osx/database_test.rb
new file mode 100644
index 0000000..56fc61d
--- /dev/null
+++ b/test/desktop/osx/database_test.rb
@@ -0,0 +1,28 @@
+require 'test_helper'
+require 'desktop/osx/database'
+
+module Desktop
+  describe OSX::Database do
+    def with_connection
+      connection = SQLite3::Database.new ':memory:'
+      yield connection
+    ensure
+      connection.close
+    end
+
+    describe '#clear_desktop_image' do
+      it 'clears contents of data table' do
+        with_connection do |connection|
+          connection.execute("CREATE TABLE data (FileName STRING)")
+          connection.execute("INSERT INTO data VALUES ('mydesktop.png')")
+
+          refute_empty connection.execute("SELECT * FROM data")
+
+          OSX::Database.new(connection).clear_desktop_image
+
+          assert_empty connection.execute("SELECT * FROM data")
+        end
+      end
+    end
+  end
+end
diff --git a/test/desktop/osx_test.rb b/test/desktop/osx/osx_test.rb
similarity index 97%
rename from test/desktop/osx_test.rb
rename to test/desktop/osx/osx_test.rb
index afe9a79..ff069c1 100644
--- a/test/desktop/osx_test.rb
+++ b/test/desktop/osx/osx_test.rb
@@ -1,5 +1,5 @@
 require 'test_helper'
-require 'desktop/osx'
+require 'desktop/osx/osx'
 require 'desktop/local_image'
 
 module Desktop

From d2957c0592c511e90fa8a72e593362a086738df4 Mon Sep 17 00:00:00 2001
From: Chris Hunt <chrishunt@github.com>
Date: Fri, 6 Jun 2014 09:00:16 -0700
Subject: [PATCH 2/2] Don't blow up if data table is missing in OSX db

---
 lib/desktop/osx/database.rb       |  8 +++++++-
 test/desktop/osx/database_test.rb | 10 ++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/desktop/osx/database.rb b/lib/desktop/osx/database.rb
index 053f131..80fdf54 100644
--- a/lib/desktop/osx/database.rb
+++ b/lib/desktop/osx/database.rb
@@ -10,7 +10,7 @@ def initialize(connection = nil)
       end
 
       def clear_desktop_image
-        clear_data
+        clear_data if data?
       end
 
       def close
@@ -19,6 +19,12 @@ def close
 
       private
 
+      def data?
+        connection.execute(
+          "SELECT name FROM sqlite_master WHERE type='table' AND name='data'"
+        ).any?
+      end
+
       def clear_data
         connection.execute 'DELETE FROM data'
         connection.execute 'VACUUM data'
diff --git a/test/desktop/osx/database_test.rb b/test/desktop/osx/database_test.rb
index 56fc61d..ec5d475 100644
--- a/test/desktop/osx/database_test.rb
+++ b/test/desktop/osx/database_test.rb
@@ -23,6 +23,16 @@ def with_connection
           assert_empty connection.execute("SELECT * FROM data")
         end
       end
+
+      it 'does not blow up if data table does not exist' do
+        with_connection do |connection|
+          assert_empty connection.execute(
+            "SELECT name FROM sqlite_master WHERE type='table' AND name='data'"
+          )
+
+          OSX::Database.new(connection).clear_desktop_image
+        end
+      end
     end
   end
 end