Add importer configuration for creator and file_path

`RecordImporter` needs to know which `User` to treat as the creator for imported
objects, and where on the file system to look for referenced file names. These
configuration options are added to `.env`, `config/importer.yml`, and
`Importer.config`. They are passed to `RecordImporter` by default on creation.

This work could be extended to allow overriding the configuration in the import
rake task by allowing that task to build a custom `RecordImporter`. For now, the
supporeted configuration is through `.env`.

Connected to #170.

.env

@@ -3,6 +3,9 @@ DATACITE_HOST='"https://mds.datacite.org"'
 DATACITE_LOGIN=DATACITE.DCE
 DATACITE_PASSWORD=YOUR_PASSWORD_HERE
 DATACITE_PREFIX=10.24354
+IMPORTER_USER='import_user@example.com'
+IMPORTER_USER_PASS=password
+IMPORTER_FILE_PATH='spec/fixtures/'
 OKCOMPUTER_LOGIN=radiohead_dev
 OKCOMPUTER_PASSWORD=th0m_y0rke
 SIDEKIQ_CONCURRENCY=5

app/importers/importer.rb

@@ -1,6 +1,28 @@
 # frozen_string_literal: true
 class Importer < Darlingtonia::Importer
-  def initialize(parser:, record_importer: MahoniaRecordImporter.new)
+  ##
+  # @return [Hash<Symbol, Object>]
+  def self.config
+    Rails.application.config_for(:importer)
+  end
+
+  def initialize(parser:, record_importer: default_record_importer)
     super
   end
+
+  def config
+    self.class.config
+  end
+
+  private
+
+    def default_creator
+      User
+        .first_or_create!(email: config['username'], password: config['password'])
+    end
+
+    def default_record_importer
+      MahoniaRecordImporter.new(creator:   default_creator,
+                                file_path: config['file_path'])
+    end
 end

app/importers/mahonia_record_importer.rb

@@ -15,8 +15,8 @@ class MahoniaRecordImporter < Darlingtonia::RecordImporter
   # @param file_path [String]
   # @param creator   [User]
   def initialize(**opts)
-    self.creator   = opts.delete(:creator)   { User.first_or_create!(email: 'import_user@example.com', password: 'password') }
-    self.file_path = opts.delete(:file_path) { 'spec/fixtures/' }
+    self.creator   = opts.delete(:creator)   || raise(ArgumentError)
+    self.file_path = opts.delete(:file_path) || raise(ArgumentError)
     super
   end
 

config/importer.yml

@@ -0,0 +1,15 @@
+---
+development:
+  username:  <%= ENV['IMPORTER_USER'] %>
+  password:  <%= ENV['IMPORTER_USER_PASS'] %>
+  file_path: <%= ENV['IMPORTER_FILE_PATH'] %>
+
+test:
+  username:  <%= ENV['IMPORTER_USER'] %>
+  password:  <%= ENV['IMPORTER_USER_PASS'] %>
+  file_path: <%= ENV['IMPORTER_FILE_PATH'] %>
+
+production:
+  username:  <%= ENV['IMPORTER_USER'] %>
+  password:  <%= ENV['IMPORTER_USER_PASS'] %>
+  file_path: <%= ENV['IMPORTER_FILE_PATH'] %>

spec/importers/importer_spec.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 require 'rails_helper'
+
 RSpec.describe Importer do
   subject(:importer) { described_class.new(parser: parser) }
   let(:file) { File.open('spec/fixtures/example.csv') }
@@ -27,6 +28,22 @@
     expect(Etd.where(title: "Unicode Description").count).to eq 1
   end
 
+  describe '.config' do
+    it 'has configuration attributes' do
+      expect(described_class.config).to include('username'  => an_instance_of(String),
+                                                'password'  => an_instance_of(String),
+                                                'file_path' => an_instance_of(String))
+    end
+  end
+
+  describe '#config' do
+    it 'has configuration attributes' do
+      expect(importer.config).to include('username'  => an_instance_of(String),
+                                         'password'  => an_instance_of(String),
+                                         'file_path' => an_instance_of(String))
+    end
+  end
+
   context "With a BePress exported csv", :clean do
     description = <<-HERE
  A far ultraviolet (UV) spectroscopic ellipsometer  system working up to 9 eV has been   developed and applied to characterize high-K- dielectric materials. These materials have   been gaining greater attention as possible  substitutes for Si02 as gate dielectrics in   aggressively scaled silicon devices. The optical  properties of representative high-K bulk   crystalline, epitaxial, and amorphous films, were investigated with far UV spectroscopic   ellipsometry and some by visible-near UV  optical transmission measurements. Optical   dielectric functions and optical band gap  energies for these materials are obtained from   these studies. The spectroscopic data and  results provide information that is needed to   select viable alternative dielectric candidate  materials with adequate band gaps, and   conduction and valence band offset energies for this application, and additionally to   provide an optical metrology for gate dielectric  films on silicon substrates. For   materials with anisotropic structure such as  single crystal DySC03and GdSc03 an   analysis process was developed to determine  the optical constant tensor.