Use localized date and time formats in interpolate_hash

[davidgumberg]

Interpolated Time's and Date's should respect default formatting options and locale.

Rails, for example, passes Date and Time ActiveRecord attributes to I18n::t.

(This may also avoid triggering some deprecation warnings in Rails eg: rails/rails#48960)

[radar]

@davidgumberg Would you mind adding a test for this please?

[davidgumberg]

@radar Thanks for the review, I've added some tests.

Is this behavior desired?

test "interpolation: given a Date with no default format set it raises I18n::MissingTranslationData" do
    assert_raises(I18n::MissingTranslationData) do
        date = Date.new(2008, 3, 1)
        interpolate(:default => '%{date}', :date => date)
    end
end

I am not really sure how much code there is in the wild that passes Date's and Time's to I18n::t, but this will break anything that does so without a :default format set for Date/Time which might be too aggressive?

The gentler alternative would be to default to sprintf as before if a format is not present.

If you have a chance, let me know what you think.