add :bulkrax_field_mappings specs for AccountSettings

app/models/concerns/account_settings.rb

@@ -164,6 +164,8 @@ def validate_contact_emails
 
   def validate_json
     json_editor_settings.each do |key|
+      next unless settings[key].present?
+
       begin
         JSON.parse(settings[key])
       rescue JSON::ParserError => e

spec/models/concerns/account_settings_spec.rb

@@ -10,6 +10,7 @@
         expect(account.public_settings(is_superadmin: true).keys.sort).to eq %i[allow_downloads
                                                                                 allow_signup
                                                                                 analytics_provider
+                                                                                bulkrax_field_mappings
                                                                                 cache_api
                                                                                 contact_email
                                                                                 contact_email_to
@@ -49,4 +50,66 @@
       end
     end
   end
+
+  describe '#bulkrax_field_mappings' do
+    context 'when the setting is blank' do
+      it 'returns the default field mappings configured in Bulkrax' do
+        expect(account.settings['bulkrax_field_mappings']).to be_nil
+        # For parity, parse Bulkrax field mappings from JSON. #to_json will stringify keys as
+        # well as turn a regex like /\|/ into (?-mix:\\|)
+        default_bulkrax_mappings = JSON.parse(Bulkrax.field_mappings.to_json)
+        default_tenant_mappings = JSON.parse(account.bulkrax_field_mappings)
+
+        expect(default_tenant_mappings).to eq(default_bulkrax_mappings)
+      end
+    end
+
+    context 'when the setting is present' do
+      let(:account) { build(:account, settings: { bulkrax_field_mappings: setting_value }) }
+
+      context 'when the value is valid JSON' do
+        let(:setting_value) do
+          {
+            'Bulkrax::CsvParser' => {
+              'fake_field' => { from: %w[fake_column], split: /\s*[|]\s*/ }
+            }
+          }.to_json
+        end
+
+        it 'parses the JSON into a Hash and prints it as pretty JSON' do
+          expect(account.bulkrax_field_mappings)
+            .to eq(JSON.pretty_generate(JSON.parse(setting_value)))
+        end
+      end
+
+      context 'when the value is not valid JSON' do
+        let(:setting_value) { 'hello world' }
+
+        it 'returns the raw value' do
+          expect(account.bulkrax_field_mappings).to eq(setting_value)
+        end
+      end
+    end
+  end
+
+  describe '#validate_json' do
+    let(:account) { build(:account, settings: { bulkrax_field_mappings: setting_value }) }
+
+    context 'when a "json_editor" setting is valid JSON' do
+      let(:setting_value) { { a: 'b' }.to_json }
+
+      it 'does not error' do
+        expect(account.valid?).to eq(true)
+      end
+    end
+
+    context 'when a "json_editor" setting is not valid JSON' do
+      let(:setting_value) { 'hello world' }
+
+      it 'adds an error to the setting' do
+        expect(account.valid?).to eq(false)
+        expect(account.errors.messages[:bulkrax_field_mappings]).to eq(["unexpected token at 'hello world'"])
+      end
+    end
+  end
 end