Don't require VACCINATED column

If the file which has been uploaded has a `VACCINE_GIVEN` or
`Vaccination type` column, we can assume that the record has been
administered.

This was already the case, but only the vaccine that the user provided
is valid. If the vaccine was invalid, this lead to a confusing scenario
where the user would see a validation error about the vaccine being
invalid and a validation error about missing `VACCINATED`. This is
wrong, once the vaccine has been fixed, the second validation error
about the `VACCINATED` column would go away, so there's no need to show
it to the user in the first place.

Author: thomasleese

app/models/immunisation_import_row.rb

@@ -377,7 +377,8 @@ def administered
       elsif "no".start_with?(vaccinated.to_s.downcase)
         false
       end
-    elsif vaccine.present?
+    elsif vaccine_name.present? ||
+          combined_vaccination_and_dose_sequence.present?
       true
     end
   end

spec/models/immunisation_import_row_spec.rb

@@ -102,6 +102,40 @@
       end
     end
 
+    context "when missing VACCINATED but a vaccine has been given" do
+      let(:data) { { "VACCINE_GIVEN" => "A vaccine" } }
+
+      it "doesn't require a VACCINATED column" do
+        expect(immunisation_import_row).to be_invalid
+        expect(immunisation_import_row.errors[:base]).not_to include(
+          "<code>VACCINATED</code> is required"
+        )
+      end
+    end
+
+    context "when missing VACCINATED but a vaccination type has been given" do
+      let(:data) { { "Vaccination type" => "HPV 1" } }
+
+      it "requires a VACCINATED column" do
+        expect(immunisation_import_row).to be_invalid
+        expect(immunisation_import_row.errors[:base]).to include(
+          "<code>VACCINATED</code> is required"
+        )
+      end
+
+      context "when SystmOne is enabled" do
+        before { Flipper.enable(:systm_one_import) }
+        after { Flipper.disable(:systm_one_import) }
+
+        it "doesn't require a VACCINATED column" do
+          expect(immunisation_import_row).to be_invalid
+          expect(immunisation_import_row.errors[:base]).not_to include(
+            "<code>VACCINATED</code> is required"
+          )
+        end
+      end
+    end
+
     context "when missing fields" do
       let(:data) { { "VACCINATED" => "Y" } }