Refactor error handling in Preservation Submission Job

Why these changes are being introduced:

The Preservation Submission Job currently handles exceptions
during SIP creation by setting the SIP's status to 'error' and
saving it. This allows us to see failed SIPs in the administrate
dashboard, but it also causes preservation to fail silently.

Relevant ticket(s):

https://mitlibraries.atlassian.net/browse/ETD-647

How this addresses that need:

This refactors the Preservation Submission Job to create SIPs
using `create!` instead of `create`, so that exceptions are
raised during the object creation. When exceptions are raised,
they are logged and added to the `results` array. Since no
SIP is created when an exception is raised by `create!`, the
logic in the `rescue` block around updating `preservation_status`
has been removed.

Side effects of this change:

* Fixtures have been adjusted to accommodate testing.
* A quasi-related test that had no assertions has been updated to
actually test something.
* The `preservation_status` of 'error' has been removed, as it
is no longer used in the app. There are currently no SIPs in
production that have this status.
* Unrelated to this change, the `baggable` module has been moved
from `app/models` to `app/lib`. This to be consistent with
where we store our other module, and to make it clear that it is
not a model.

app/jobs/preservation_submission_job.rb

@@ -6,15 +6,13 @@ def perform(theses)
     results = { total: theses.count, processed: 0, errors: [] }
     theses.each do |thesis|
       Rails.logger.info("Thesis #{thesis.id} is now being prepared for preservation")
-      sip = thesis.submission_information_packages.create
+      sip = thesis.submission_information_packages.create!
       preserve_sip(sip)
       Rails.logger.info("Thesis #{thesis.id} has been sent to preservation")
       results[:processed] += 1
     rescue StandardError, Aws::Errors => e
       preservation_error = "Thesis #{thesis.id} could not be preserved: #{e}"
       Rails.logger.info(preservation_error)
-      sip.preservation_status = 'error'
-      sip.save
       results[:errors] << preservation_error
     end
     ReportMailer.preservation_results_email(results).deliver_now if results[:total].positive?

app/models/submission_information_package.rb

@@ -31,7 +31,7 @@ class SubmissionInformationPackage < ApplicationRecord
 
   before_create :set_metadata, :set_bag_declaration, :set_manifest, :set_bag_name
 
-  enum preservation_status: %i[unpreserved preserved error]
+  enum preservation_status: %i[unpreserved preserved]
 
   def data
     file_locations = {}

test/fixtures/archivematica_accessions.yml

@@ -28,3 +28,7 @@ june_2018_001:
 june_2021_001:
   accession_number: '2021_001'
   degree_period: june_2021
+
+june_2022_001:
+  accession_number: '2022_001'
+  degree_period: june_2022

test/fixtures/degree_periods.yml

@@ -28,3 +28,7 @@ june_2018:
 june_2021:
   grad_month: 'June'
   grad_year: '2021'
+
+june_2022:
+  grad_month: 'June'
+  grad_year: '2022'

test/fixtures/theses.yml

@@ -275,6 +275,7 @@ engineer:
   metadata_complete: true
   issues_found: false
   publication_status: Published
+  dspace_handle: '3456/7890'
   proquest_exported: 'Full harvest'
 
 long_abstracts_are_fun:

test/jobs/preservation_submission_job_test.rb

@@ -33,7 +33,19 @@ def setup_thesis
   end
 
   test 'creates multiple SIPs' do
-    theses = [setup_thesis, theses(:published)]
+    thesis_one = setup_thesis
+    thesis_two = theses(:engineer)
+    assert_equal 0, thesis_one.submission_information_packages.count
+    assert_equal 0, thesis_two.submission_information_packages.count
+
+    theses = [thesis_one, thesis_two]
+    PreservationSubmissionJob.perform_now(theses)
+    assert_equal 1, thesis_one.submission_information_packages.count
+    assert_equal 1, thesis_two.submission_information_packages.count
+
+    PreservationSubmissionJob.perform_now(theses)
+    assert_equal 2, thesis_one.submission_information_packages.count
+    assert_equal 2, thesis_two.submission_information_packages.count
   end
 
   test 'updates preservation_status to "preserved" after successfully processing a thesis' do
@@ -51,15 +63,21 @@ def setup_thesis
     end
   end
 
-  test 'rescues exceptions by updating preservation_status to "error"' do
-    thesis = theses(:one)
-    PreservationSubmissionJob.perform_now([thesis])
-    assert_equal 'error', thesis.submission_information_packages.last.preservation_status
+  test 'throws exceptions when a thesis is unbaggable' do
+    assert_raises StandardError do
+      PreservationSubmissionJob.perform_now([theses[:one]])
+    end
+
+    assert_nothing_raised do
+      PreservationSubmissionJob.perform_now([setup_thesis])
+    end
   end
 
-  test 'does not update preserved_at if the job enters an error state' do
+  test 'does not create a SIP if the job enters an error state' do
     thesis = theses(:one)
+    assert_empty thesis.submission_information_packages
+
     PreservationSubmissionJob.perform_now([thesis])
-    assert_nil thesis.submission_information_packages.last.preserved_at
+    assert_empty thesis.submission_information_packages
   end
 end