Handle empty arrays

The previous commit failed to account for the case where `#find_by_sql`
returns no results.

lib/art_vandelay.rb

@@ -41,7 +41,9 @@ def csv
  elsif records.is_a?(ActiveRecord::Base)
  csv_exports << CSV.parse(generate_csv(records), headers: true)
  elsif records.is_a?(Array)
- csv_exports << CSV.parse(generate_csv(records), headers: true)
+ if records.any?
+ csv_exports << CSV.parse(generate_csv(records), headers: true)
+ end
  end
 
  Result.new(csv_exports)
@@ -125,6 +127,8 @@ def model_name
  records.model_name.name
  when Array
  records.first.model_name.name
+ else
+ raise "Unsupported export: #{records.class}"
  end
  end
 

test/art_vandelay_test.rb

@@ -92,6 +92,12 @@ class Export < ArtVandelayTest
  )
  end
 
+ test "it does not create a CSV when passed an empty Array" do
+ result = ArtVandelay::Export.new([]).csv
+
+ assert_empty result.csv_exports
+ end
+
  test "it controlls what data is filtered" do
  user = User.create!(email: "[email protected]", password: "password")
  ArtVandelay.setup do |config|