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Diffstat (limited to 'railties/doc/guides/source/creating_plugins/string_to_squawk.txt')
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1 files changed, 0 insertions, 103 deletions
diff --git a/railties/doc/guides/source/creating_plugins/string_to_squawk.txt b/railties/doc/guides/source/creating_plugins/string_to_squawk.txt deleted file mode 100644 index 50516cef69..0000000000 --- a/railties/doc/guides/source/creating_plugins/string_to_squawk.txt +++ /dev/null @@ -1,103 +0,0 @@ -== Add a `to_squawk` method to String == - -To update a core class you will have to: - - * Write tests for the desired functionality. - * Create a file for the code you wish to use. - * Require that file from your 'init.rb'. - -Most plugins store their code classes in the plugin's lib directory. When you add a file to the lib directory, you must also require that file from 'init.rb'. The file you are going to add for this tutorial is 'lib/core_ext.rb'. - -First, you need to write the tests. Testing plugins is very similar to testing rails apps. The generated test file should look something like this: - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/test/core_ext_test.rb - -require 'test/unit' - -class CoreExtTest < Test::Unit::TestCase - # Replace this with your real tests. - def test_this_plugin - flunk - end -end --------------------------------------------------------- - -Start off by removing the default test, and adding a require statement for your test helper. - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/test/core_ext_test.rb - -require 'test/unit' -require File.dirname(__FILE__) + '/test_helper.rb' - -class CoreExtTest < Test::Unit::TestCase -end --------------------------------------------------------- - -Navigate to your plugin directory and run `rake test`: - --------------------------------------------------------- -cd vendor/plugins/yaffle -rake test --------------------------------------------------------- - -Your test should fail with `no such file to load -- ./test/../lib/core_ext.rb (LoadError)` because we haven't created any file yet. Create the file 'lib/core_ext.rb' and re-run the tests. You should see a different error message: - --------------------------------------------------------- -1.) Failure ... -No tests were specified --------------------------------------------------------- - -Great - now you are ready to start development. The first thing we'll do is to add a method to String called `to_squawk` which will prefix the string with the word ``squawk!''. The test will look something like this: - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -class CoreExtTest < Test::Unit::TestCase - def test_string_should_respond_to_squawk - assert_equal true, "".respond_to?(:to_squawk) - end - - def test_string_prepend_empty_strings_with_the_word_squawk - assert_equal "squawk!", "".to_squawk - end - - def test_string_prepend_non_empty_strings_with_the_word_squawk - assert_equal "squawk! Hello World", "Hello World".to_squawk - end -end --------------------------------------------------------- - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -require "core_ext" --------------------------------------------------------- - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/lib/core_ext.rb - -String.class_eval do - def to_squawk - "squawk! #{self}".strip - end -end --------------------------------------------------------- - -When monkey-patching existing classes it's often better to use `class_eval` instead of opening the class directly. - -To test that your method does what it says it does, run the unit tests. To test this manually, fire up a console and start squawking: - --------------------------------------------------------- -$ ./script/console ->> "Hello World".to_squawk -=> "squawk! Hello World" --------------------------------------------------------- - -If that worked, congratulations! You just created your first test-driven plugin that extends a core ruby class. |