Add term filter to summary of authors_not_graduated data

Why these changes are being introduced:

Report#data_authors_not_graduated does not include a grad_date filter,
so all theses with ungraduated authors are shown for each term
instead of just the theses for the corresponding term.

Relevant ticket(s):

https://mitlibraries.atlassian.net/browse/ETD-429

How this addresses that need:

This adds the term filter into Report#data_authors_not_graduated

Side effects of this change:

N/A.

app/models/report.rb

@@ -235,9 +235,8 @@ def data_authors_not_graduated
     row_data = {}
     terms = Thesis.all.pluck(:grad_date).uniq.sort
     terms.each do |term|
-      row_data[term] = Thesis.with_files.includes(authors: :user).includes(:departments).select do |t|
-        !t.authors_graduated?
-      end.uniq.count
+      row_data[term] = Thesis.with_files.where('grad_date = ?', term).includes(authors: :user).includes(:departments)
+                             .reject(&:authors_graduated?).count
     end
     {
       label: 'Authors not graduated',

test/models/report_test.rb

@@ -51,6 +51,28 @@ class ReportTest < ActiveSupport::TestCase
     assert_equal result['departments'][0][:data].values, [0, 3, 0, 0, 0, 0, 0, 4, 0]
   end
 
+  test 'index includes summary data of authors not graduated' do
+    thesis = theses(:bachelor)
+    another_thesis = theses(:published)
+    assert_not_equal thesis.grad_date, another_thesis.grad_date
+    assert thesis.files?
+    assert another_thesis.files?
+
+    a = thesis.authors.first
+    a.graduation_confirmed = false
+    a.save
+    assert_not thesis.authors_graduated?
+
+    a = another_thesis.authors.first
+    a.graduation_confirmed = false
+    a.save
+    assert_not another_thesis.authors_graduated?
+
+    r = Report.new
+    result = r.index_data
+    assert_equal result['summary'][5][:data].values, [0, 1, 0, 0, 0, 0, 0, 1, 0]
+  end
+
   # ~~~~ Term detail report
   test 'term detail includes a breakdown of departments' do
     r = Report.new