Add failsafe measures to CSVConverter

Fixes #1685

Author: mshibuya

lib/rails_admin/support/csv_converter.rb

@@ -3,22 +3,24 @@
 
 module RailsAdmin
   class CSVConverter
-    def initialize(objects = [], schema = {})
+    def initialize(objects = [], schema = nil)
       @fields = []
       @associations = []
+      schema ||= {}
 
       return self if (@objects = objects).blank?
 
       @model = objects.dup.first.class
       @abstract_model = RailsAdmin::AbstractModel.new(@model)
       @model_config = @abstract_model.config
       @methods = [(schema[:only] || []) + (schema[:methods] || [])].flatten.compact
-      @fields = @methods.collect { |m| export_fields_for(m).first }
+      @fields = @methods.collect { |m| export_field_for(m) }.compact
       @empty = ::I18n.t('admin.export.empty_value_for_associated_objects')
       schema_include = schema.delete(:include) || {}
 
       @associations = schema_include.each_with_object({}) do |(key, values), hash|
-        association = association_for(key)
+        association = export_field_for(key)
+        next unless association&.association?
         model_config = association.associated_model_config
         abstract_model = model_config.abstract_model
         methods = [(values[:only] || []) + (values[:methods] || [])].flatten.compact
@@ -28,7 +30,7 @@ def initialize(objects = [], schema = {})
           model: abstract_model.model,
           abstract_model: abstract_model,
           model_config: model_config,
-          fields: methods.collect { |m| export_fields_for(m, model_config).first },
+          fields: methods.collect { |m| export_field_for(m, model_config) }.compact,
         }
         hash
       end
@@ -61,12 +63,8 @@ def to_csv(options = {})
 
   private
 
-    def association_for(key)
-      export_fields_for(key).detect(&:association?)
-    end
-
-    def export_fields_for(method, model_config = @model_config)
-      model_config.export.fields.select { |f| f.name == method }
+    def export_field_for(method, model_config = @model_config)
+      model_config.export.fields.detect { |f| f.name == method }
     end
 
     def generate_csv_string(options)

spec/integration/actions/export_spec.rb

@@ -92,6 +92,12 @@
     end
   end
 
+  it 'does not break when nothing is checked' do
+    visit export_path(model_name: 'comment')
+    all('input[type="checkbox"]').each(&:uncheck)
+    expect { click_button 'Export to csv' }.not_to raise_error
+  end
+
   context 'with csv format' do
     it 'exports with modified schema' do
       page.driver.post(export_path(model_name: 'player', schema: @non_default_schema, csv: true, all: true, csv_options: {generator: {col_sep: ','}}))

spec/rails_admin/support/csv_converter_spec.rb

@@ -17,6 +17,28 @@
     expect(RailsAdmin::CSVConverter.new(objects, schema).to_csv({})[2]).to match(/Number,Name/)
   end
 
+  describe '#generate_csv_header' do
+    let(:objects) { FactoryBot.create_list :player, 1 }
+    before do
+      RailsAdmin.config(Player) do
+        export do
+          field :number
+          field :name
+        end
+      end
+    end
+
+    it 'does not break when non-existent fields are given' do
+      expect(RailsAdmin::CSVConverter.new(objects, {only: [:name, :foo], include: {bar: :baz}}).send(:generate_csv_header)).
+        to eq ["Name"]
+    end
+
+    it 'does not break when non-association fields are given to :include' do
+      expect(RailsAdmin::CSVConverter.new(objects, {only: [:name, :foo], include: {name: :name}}).send(:generate_csv_header)).
+        to eq ["Name"]
+    end
+  end
+
   describe '#to_csv' do
     before do
       RailsAdmin.config(Player) do