如何获取Rails夹具实例的内容的哈希值？

Question

This is using Rails 4.2.0, Ruby 2.2.0.

What I'd like to do is use the data contained in a fixture object to verify that duplicates are caught before insertion into the same database:

  test "identical entries should be impossible to create" do
    dup_entry = Entry.new(entries(:test_entry))
    assert_not dup_entry.save
  end

(where Entry is a well-defined model with a controller method .new , and test_entry is a fixture containing some valid Entry instance.)

Unfortunately, this doesn't work because entries(:test_entry) is going to be an Entry , not a hash accepted by Entry.new .

I know that I can access fixture properties with an expression of the form fixture_objname.property in the associated tests, since whatever is specified in the YAML will automatically be inserted into the database and loaded. The problem with this is that I have to manually retype a bunch of property names for the object I just specified in the YAML, which seems silly.

The documentation also says I can get the actual model instances by adding self.use_instantiated_fixtures = true to the test class. However, there don't seem to be any instance_methods that will dump out the fixture's model instance ( test_entry ) in a hash format to feed back into the .new method.

Is there an idiomatic way to get what I want, or a different, easier way?

Answer 1

I believe you're looking for something like:

entries(:test_entry).attributes
entries(:test_entry).attributes.class # => Hash

You can also remove properties if needed:

entries(:admin).attributes.except("id")

Hope this helps.