add sunset year for visible terms (#2434)

* add sunset year for visible terms

* cover all the possible test cases

lib/term_year.rb

@@ -28,6 +28,9 @@
 
   const_set 'VISIBLE_TERMS', [:spring, :summer, :fall, :winter]
 
+  SUNSET_YEAR = 2023
+  SUNSET_YEAR_VISIBLE_TERMS = [:spring]
+
   attr_reader :starts_at, :ends_at
 
   def initialize(term, year)
@@ -45,14 +48,19 @@ def initialize(term, year)
     @ends_at   = end_proc.call(year) - 1.second
   end
 
+  def self.visible_terms(year)
+    return [] if year > SUNSET_YEAR
+    year == SUNSET_YEAR ? SUNSET_YEAR_VISIBLE_TERMS : TermYear::VISIBLE_TERMS
+  end
+
   def self.visible_term_years(current_time = Time.current)
     current_year = current_time.year
 
-    current_year_visible_term_years = TermYear::VISIBLE_TERMS.map do |term|
+    current_year_visible_term_years = visible_terms(current_year).map do |term|
       TermYear.new(term, current_year)
     end.select { |term_year| term_year.ends_at > current_time }
 
-    next_year_visible_term_years = TermYear::VISIBLE_TERMS.map do |term|
+    next_year_visible_term_years = visible_terms(current_year + 1).map do |term|
       TermYear.new(term, current_year + 1)
     end.select { |term_year| term_year.ends_at <= current_time + 1.year }
 

spec/lib/term_year_spec.rb

@@ -127,33 +127,106 @@
     end
   end
 
-  it 'returns the correct visible_term_years' do
-    current_year = Time.current.year
-
-    spring_date_time        = DateTime.parse("March 1st, #{current_year}"   )
-    spring_summer_date_time = DateTime.parse("June 1st, #{current_year}"    )
-    summer_fall_date_time   = DateTime.parse("July 1st, #{current_year}"    )
-    fall_date_time          = DateTime.parse("November 1st, #{current_year}")
-
-    expect(TermYear.visible_term_years(spring_date_time)).to eq [
-      TermYear.new(:spring, current_year), TermYear.new(:summer, current_year    ),
-      TermYear.new(:fall,   current_year),
-      TermYear.new(:winter, current_year)
-    ]
-
-    expect(TermYear.visible_term_years(spring_summer_date_time)).to eq [
-      TermYear.new(:spring, current_year    ), TermYear.new(:summer, current_year ),
-      TermYear.new(:fall,   current_year    ), TermYear.new(:winter, current_year )
-    ]
-
-    expect(TermYear.visible_term_years(summer_fall_date_time)).to eq [
-      TermYear.new(:summer, current_year ), TermYear.new(:fall,   current_year ),
-      TermYear.new(:winter, current_year ), TermYear.new(:spring, current_year + 1)
-    ]
-
-    expect(TermYear.visible_term_years(fall_date_time)).to eq [
-      TermYear.new(:fall,   current_year    ), TermYear.new(:winter, current_year ),
-      TermYear.new(:spring, current_year + 1), TermYear.new(:summer, current_year + 1),
-    ]
+  describe 'visible terms' do
+    let(:current_year)            { Time.current.year }
+    let(:spring_date_time)        { DateTime.parse "March 1st, #{current_year}"    }
+    let(:spring_summer_date_time) { DateTime.parse "June 1st, #{current_year}"     }
+    let(:summer_fall_date_time)   { DateTime.parse "July 1st, #{current_year}"     }
+    let(:fall_date_time)          { DateTime.parse "November 1st, #{current_year}" }
+
+    context 'sunset is in two years' do
+      before { stub_const('SUNSET_YEAR', current_year + 2) }
+
+      it 'returns the correct visible_term_years' do
+        expect(TermYear.visible_term_years(spring_date_time)).to eq [
+          TermYear.new(:spring, current_year),
+          TermYear.new(:summer, current_year),
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year)
+        ]
+
+        expect(TermYear.visible_term_years(spring_summer_date_time)).to eq [
+          TermYear.new(:spring, current_year),
+          TermYear.new(:summer, current_year),
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year)
+        ]
+
+        expect(TermYear.visible_term_years(summer_fall_date_time)).to eq [
+          TermYear.new(:summer, current_year),
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year),
+          TermYear.new(:spring, current_year + 1)
+        ]
+
+        expect(TermYear.visible_term_years(fall_date_time)).to eq [
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year),
+          TermYear.new(:spring, current_year + 1),
+          TermYear.new(:summer, current_year + 1)
+        ]
+      end
+    end
+
+    context 'sunset is next year' do
+      before { stub_const('SUNSET_YEAR', current_year + 1) }
+
+      it 'returns the correct visible_term_years' do
+        expect(TermYear.visible_term_years(spring_date_time)).to eq [
+          TermYear.new(:spring, current_year),
+          TermYear.new(:summer, current_year),
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year)
+        ]
+
+        expect(TermYear.visible_term_years(spring_summer_date_time)).to eq [
+          TermYear.new(:spring, current_year),
+          TermYear.new(:summer, current_year),
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year)
+        ]
+
+        expect(TermYear.visible_term_years(summer_fall_date_time)).to eq [
+          TermYear.new(:summer, current_year),
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year),
+          TermYear.new(:spring, current_year + 1)
+        ]
+
+        expect(TermYear.visible_term_years(fall_date_time)).to eq [
+          TermYear.new(:fall,   current_year),
+          TermYear.new(:winter, current_year),
+          TermYear.new(:spring, current_year + 1)
+        ]
+      end
+    end
+
+    context 'sunset is current year' do
+      before { stub_const('SUNSET_YEAR', current_year) }
+
+      it 'returns the correct visible_term_years' do
+        expect(TermYear.visible_term_years(spring_date_time)).to eq [
+          TermYear.new(:spring, current_year),
+        ]
+
+        expect(TermYear.visible_term_years(spring_summer_date_time)).to eq [
+          TermYear.new(:spring, current_year),
+        ]
+
+        expect(TermYear.visible_term_years(summer_fall_date_time)).to eq []
+        expect(TermYear.visible_term_years(fall_date_time)).to eq []
+      end
+    end
+
+    context 'sunset is in the past' do
+      before { stub_const('SUNSET_YEAR', current_year - 1) }
+
+      it 'returns the correct visible_term_years' do
+        expect(TermYear.visible_term_years(spring_date_time)).to eq []
+        expect(TermYear.visible_term_years(spring_summer_date_time)).to eq []
+        expect(TermYear.visible_term_years(summer_fall_date_time)).to eq []
+        expect(TermYear.visible_term_years(fall_date_time)).to eq []
+      end
+    end
   end
 end