support multiple sasl_passwd entries

with tests

Signed-off-by: Felix Wong <gnowxilef@gmail.com>

test/integration/sasl_auth_none/serverspec/sasl_auth_none_spec.rb

@@ -0,0 +1,31 @@
+# Copyright:: 2012-2017, Chef Software, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+require_relative './spec_helper'
+
+describe 'postfix::sasl_auth' do
+  let(:sasl_passwd_file) { '/etc/postfix/sasl_passwd' }
+
+  it 'manages postfix sasl_passwd' do
+    expect(file(sasl_passwd_file).content).to match(/^# Auto-generated by Chef/)
+  end
+
+  it 'configures postfix to use the sasl_passwd file' do
+    expect(file('/etc/postfix/main.cf').content).to match(/^\s*smtp_sasl_password_maps\s*=.*#{sasl_passwd_file}\s*$/)
+  end
+
+  it 'configures postfix sasl_passwd with nothing in it' do
+    expect(file(sasl_passwd_file).content).to match(/^# This file is generated by Chef for .*\n/)
+  end
+end