Handle additional GraduationHelper edge cases

app/helpers/graduation_helper.rb

@@ -1,13 +1,23 @@
 module GraduationHelper
   # Given a graduation date and an embargo length, calculate the embargo_release_date.
-  # This assumes embargo_length values like "6 months", "2 months", "6 years"
-  def self.embargo_length_to_embargo_release_date(graduation_date, embargo_length)
-    if embargo_length == InProgressEtd::NO_EMBARGO
+  def self.embargo_length_to_embargo_release_date(graduation_date, requested_embargo)
+    if requested_embargo == InProgressEtd::NO_EMBARGO || requested_embargo.blank?
+      # No post-graduation embargo to apply
+      Rails.logger.warn "Treating empty requested_embargo as 'None'" if requested_embargo.blank?
       graduation_date
     else
-      number, units = embargo_length.split(" ")
+      # Calculate embargo expiration date
+      number, units = requested_embargo.split(" ")
+      raise ArgumentError, "Unexpected embargo length '#{requested_embargo}'" unless valid_length(number, units)
       graduation_date = Date.parse(graduation_date) if graduation_date.class == String
       graduation_date + Integer(number).send(units.to_sym)
     end
   end
+
+  # Ensure valid values like "6 months", "2 months", "6 years"
+  def self.valid_length(number, units)
+    valid_quantity = number.to_i > 0
+    valid_units = ['months', 'year', 'years'].include?(units)
+    valid_quantity && valid_units
+  end
 end

spec/helpers/graduation_helper_spec.rb

@@ -3,18 +3,45 @@
 require 'rails_helper'
 
 RSpec.describe GraduationHelper, type: :helper do
-  context "calculating embargo_release_date" do
-    it "can interpret a length of '6 months'" do
-      e = described_class.embargo_length_to_embargo_release_date(Time.zone.today, "6 months")
-      expect(e).to eq Time.zone.today + 6.months
+  let(:graduation_date) { "2019-08-17" }
+
+  context "with valid embargo_length and graduation_date" do
+    it "inteprets month units" do
+      release_date = described_class.embargo_length_to_embargo_release_date(graduation_date, "6 months")
+      expect(release_date).to eq graduation_date.to_datetime + 6.months
     end
-    it "can interpret a length of '3 years'" do
-      e = described_class.embargo_length_to_embargo_release_date(Time.zone.today, "3 years")
-      expect(e).to eq Time.zone.today + 3.years
+
+    it "interprets year units" do
+      release_date = described_class.embargo_length_to_embargo_release_date(graduation_date, "3 years")
+      expect(release_date).to eq graduation_date.to_datetime + 3.years
     end
+
     it "can interpret a length of 'None - open access immediately'" do
-      e = described_class.embargo_length_to_embargo_release_date(Time.zone.today, "None - open access immediately")
-      expect(e).to be <= Time.zone.today
+      release_date = described_class.embargo_length_to_embargo_release_date(graduation_date, "None - open access immediately")
+      expect(release_date).to eq graduation_date
+    end
+  end
+
+  context "with unexpected values" do
+    before { allow(Rails.logger).to receive(:warn) }
+
+    it "handles exmpty embargo_length as 'None'" do
+      embargo_length = ''
+      release_date = described_class.embargo_length_to_embargo_release_date(graduation_date, embargo_length)
+      expect(release_date).to eq graduation_date
+      expect(Rails.logger).to have_received(:warn).with("Treating empty requested_embargo as 'None'")
+    end
+
+    it "handles nil embargo_length as 'None'" do
+      embargo_length = nil
+      release_date = described_class.embargo_length_to_embargo_release_date(graduation_date, embargo_length)
+      expect(release_date).to eq graduation_date
+      expect(Rails.logger).to have_received(:warn).with("Treating empty requested_embargo as 'None'")
+    end
+
+    it "raises an error for random embargo_lengths" do
+      embargo_length = 'Four score and seven years'
+      expect { described_class.embargo_length_to_embargo_release_date(graduation_date, embargo_length) }.to raise_error ArgumentError
     end
   end
 end