The overall response rate is artifically lower because we are including the number of all the students at the school, not just the number of students that took the survey. Updated the overall response rate presenter to return the count of only the grades that took the student survey.

app/presenters/response_rate_presenter.rb

@@ -14,6 +14,8 @@ class ResponseRatePresenter
   end
 
   def percentage
+    return 0 if respondents_count.zero?
+
     cap_at_100(actual_count.to_f / respondents_count.to_f * 100).round
   end
 
@@ -33,9 +35,30 @@ class ResponseRatePresenter
   end
 
   def respondents_count
-    respondents = Respondent.find_by(school:, academic_year:)
-    count = respondents.total_students if focus == :student
+    return 0 if respondents.nil?
+
+    count = enrollment if focus == :student
     count = respondents.total_teachers if focus == :teacher
     count
   end
+
+  def enrollment
+    SurveyItemResponse.where(school:, academic_year:, grade: grades,
+                             survey_item: SurveyItem.student_survey_items)
+                      .select(:grade)
+                      .distinct
+                      .pluck(:grade)
+                      .reject(&:nil?)
+                      .map do |grade|
+      respondents.counts_by_grade[grade]
+    end.sum.to_f
+  end
+
+  def respondents
+    Respondent.find_by(school:, academic_year:)
+  end
+
+  def grades
+    respondents.counts_by_grade.keys
+  end
 end

spec/presenters/response_rate_presenter_spec.rb

@@ -45,8 +45,8 @@ describe ResponseRatePresenter do
       end
 
       it "ignores all teacher items and only gets the modified date of the last student item" do
-        rdate = ResponseRatePresenter.new(focus: :student, academic_year:, school:).date
-        expect(rdate).to eq(newest_student_survey_response.updated_at)
+        percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).date
+        expect(percentage).to eq(newest_student_survey_response.updated_at)
       end
     end
     context "when focus is teacher" do
@@ -58,8 +58,8 @@ describe ResponseRatePresenter do
       end
 
       it "ignores all student responses and only gets the modified date of the last teacher item" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).date
-        expect(rdate).to eq(newest_teacher_survey_response.updated_at)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).date
+        expect(percentage).to eq(newest_teacher_survey_response.updated_at)
       end
     end
   end
@@ -71,8 +71,8 @@ describe ResponseRatePresenter do
     end
     context "when no survey responses are found for a school" do
       it "returns a response rate of 0" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
-        expect(rdate).to eq(0)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
+        expect(percentage).to eq(0)
       end
     end
 
@@ -83,8 +83,8 @@ describe ResponseRatePresenter do
       end
 
       it "returns a response rate of 100" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
-        expect(rdate).to eq(100)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
+        expect(percentage).to eq(100)
       end
     end
 
@@ -95,8 +95,8 @@ describe ResponseRatePresenter do
       end
 
       it "returns a response rate of 100" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
-        expect(rdate).to eq(100)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
+        expect(percentage).to eq(100)
       end
     end
 
@@ -107,8 +107,8 @@ describe ResponseRatePresenter do
       end
 
       it "returns a response rate of 75" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
-        expect(rdate).to eq(75)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
+        expect(percentage).to eq(75)
       end
     end
     context "when one quarter of the teachers responded to the survey" do
@@ -118,8 +118,8 @@ describe ResponseRatePresenter do
       end
 
       it "returns a response rate of 25" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
-        expect(rdate).to eq(25)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
+        expect(percentage).to eq(25)
       end
     end
     context "When the percentage is not a round number" do
@@ -129,8 +129,8 @@ describe ResponseRatePresenter do
       end
 
       it "its rounded to the nearest integer" do
-        rdate = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
-        expect(rdate).to eq(23)
+        percentage = ResponseRatePresenter.new(focus: :teacher, academic_year:, school:).percentage
+        expect(percentage).to eq(23)
       end
     end
 
@@ -141,8 +141,8 @@ describe ResponseRatePresenter do
       end
 
       it "returns a response rate of 100" do
-        rdate = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
-        expect(rdate).to eq(100)
+        percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+        expect(percentage).to eq(100)
       end
     end
     context "when half of all students responded" do
@@ -152,8 +152,98 @@ describe ResponseRatePresenter do
       end
 
       it "returns a response rate of 50" do
-        rdate = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
-        expect(rdate).to eq(50)
+        percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+        expect(percentage).to eq(50)
+      end
+    end
+
+    context "when only a subset of grades was given the survey" do
+      before :each do
+        respondents.one = 20
+        respondents.two = 20
+        respondents.three = 20
+        respondents.four = 20
+        respondents.five = 20
+        respondents.save
+      end
+      context "and only first grade was given the survey" do
+        context "and all the first grade responded" do
+          before :each do
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 1)
+          end
+          it "returns a response rate of 100" do
+            percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+            expect(percentage).to eq(100)
+          end
+        end
+
+        context "and half of first grade responded" do
+          before :each do
+            create_list(:survey_item_response, 10, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 1)
+          end
+          it "returns a response rate of 50" do
+            percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+            expect(percentage).to eq(50)
+          end
+        end
+      end
+
+      context "and two grades responded" do
+        context "and both grades responded fully" do
+          before :each do
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 1)
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 2)
+          end
+          it "returns a response rate of 100" do
+            percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+            expect(percentage).to eq(100)
+          end
+        end
+        context "and half of first grade responded" do
+          before :each do
+            create_list(:survey_item_response, 10, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 1)
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 2)
+          end
+          it "returns a response rate of 75" do
+            percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+            expect(percentage).to eq(75)
+          end
+        end
+        context "and a quarter of first grade responded" do
+          before :each do
+            create_list(:survey_item_response, 5, school:, academic_year:,
+                                                  survey_item: student_survey_item, grade: 1)
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 2)
+          end
+          it "returns a response rate of 63 (rounded up from 62.5)" do
+            percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+            expect(percentage).to eq(63)
+          end
+        end
+      end
+
+      context "and three grades responded" do
+        context "and all three grades responded fully" do
+          before :each do
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 1)
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 2)
+            create_list(:survey_item_response, 20, school:, academic_year:,
+                                                   survey_item: student_survey_item, grade: 3)
+          end
+          it "returns a response rate of 100" do
+            percentage = ResponseRatePresenter.new(focus: :student, academic_year:, school:).percentage
+            expect(percentage).to eq(100)
+          end
+        end
       end
     end
   end