Show environment for the newly added dev domain

All non-production environments show a banner in the top left corner of
the page, and a prefix in emails sent from the application, to indicate
what environment they are coming from.

This is in order to avoid user confusion about what site they are on,
and reassure them that they are not accidentally modifying production
data without intending to.

We cannot use Rails.env, because the Rails env is production for all -
in that they are live sites, not local dev or testing. We have to use
the hostname from the `DOMAIN` environment variable.

When we originally added the banner, there was no dev environment, and
the script defaults to not showing a banner for any unrecognised hosts,
to avoid showing a banner unintentionally.

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Add `is_oda` attribute to reports and populate it to `false` for all existing ISPF reports
 - Amend report validation to permit two editable reports per fund and organisation, as long as they have different ODA types
 - Amend the check for a pre-existing later report to take ODA type into account
+- Show environment banner on the `dev` domain
 
 ## Release 138 - 2023-10-27
 

app/helpers/application_helper.rb

@@ -45,7 +45,7 @@ def environment_name
     case hostname
     when "www"
       "production"
-    when "staging", "sandbox", "training"
+    when "staging", "sandbox", "training", "dev"
       hostname
     when "pentest"
       "training"
@@ -55,7 +55,7 @@ def environment_name
   end
 
   def display_env_name?
-    environment_name.in? %w[training staging sandbox development]
+    environment_name.in? %w[training staging sandbox dev development]
   end
 
   def environment_mailer_prefix

spec/helpers/application_helper_spec.rb

@@ -76,37 +76,45 @@
       end
 
       context "when the domain is 'https://training'" do
-        it "returns 'training" do
+        it "returns 'training'" do
           ClimateControl.modify DOMAIN: "https://training.report-official-development-assistance.service.gov.uk" do
             expect(helper.environment_name).to eql("training")
           end
         end
       end
 
       context "when the domain is 'https://pentest'" do
-        it "returns 'training" do
+        it "returns 'training'" do
           ClimateControl.modify DOMAIN: "https://pentest.report-official-development-assistance.service.gov.uk" do
             expect(helper.environment_name).to eql("training")
           end
         end
       end
 
       context "when the domain is 'https://sandbox'" do
-        it "returns 'sandbox" do
+        it "returns 'sandbox'" do
           ClimateControl.modify DOMAIN: "sandbox.report-official-development-assistance.service.gov.uk" do
             expect(helper.environment_name).to eql("sandbox")
           end
         end
       end
 
       context "when the domain is 'https://staging'" do
-        it "returns 'staging" do
+        it "returns 'staging'" do
           ClimateControl.modify DOMAIN: "https://staging.report-official-development-assistance.service.gov.uk" do
             expect(helper.environment_name).to eql("staging")
           end
         end
       end
 
+      context "when the domain is 'https://dev'" do
+        it "returns 'dev'" do
+          ClimateControl.modify DOMAIN: "https://dev.report-official-development-assistance.service.gov.uk" do
+            expect(helper.environment_name).to eql("dev")
+          end
+        end
+      end
+
       context "when the domain is something not listed" do
         it "returns the Rails environment" do
           ClimateControl.modify DOMAIN: "https://something" do
@@ -126,9 +134,9 @@
   end
 
   describe "#display_env_name?" do
-    context "when the environment_name is one of training, staging, sandbox, or development" do
+    context "when the environment_name is one of training, staging, sandbox, dev, or development" do
       it "returns true" do
-        %w[training staging sandbox development].each do |env_name|
+        %w[training staging sandbox dev development].each do |env_name|
           allow(helper).to receive(:environment_name).and_return(env_name)
           expect(helper.display_env_name?).to be(true)
         end
@@ -146,9 +154,9 @@
   end
 
   describe "#environment_mailer_prefix" do
-    context "when the environment_name is one of training, staging, sandbox, or development" do
+    context "when the environment_name is one of training, staging, sandbox, dev, or development" do
       it "returns the titleised environment name enclosed in square brackets and with a trailing space" do
-        %w[training staging sandbox development].each do |env_name|
+        %w[training staging sandbox dev development].each do |env_name|
           allow(helper).to receive(:environment_name).and_return(env_name)
           expect(helper.environment_mailer_prefix).to eql("[#{env_name.titleize}] ")
         end