Use the new json() helper

app.rb

@@ -1,6 +1,5 @@
 require "bundler/setup"
 require "sinatra"
-require "sinatra/json"
 require "sinatra/cookies"
 require "sinatra/multi_route"
 require "time"
@@ -243,18 +242,16 @@ get "/" do
 end
 
 get "/env", provides: "json" do
-  content_type :json
+  pretty = params.key? :pretty
 
-  return JSON.pretty_generate ENV.sort.to_h if params.key? "pretty"
-
-  JSON.generate ENV.sort.to_h
+  json ENV.sort.to_h, pretty:
 end
 
 get "/headers", provides: "json" do
+  pretty = params.key? :pretty
   h = req_headers
-  return JSON.pretty_generate h if params.key? "pretty"
 
-  JSON.generate h
+  json h, pretty:
 end
 
 get "/livez" do
@@ -268,6 +265,7 @@ end
 get "/livez/uptime" do
   tt = TickTock.new
   x = {started_at: tt.started_at, seconds: tt.uptime.to_i, human: human_time(tt.uptime.to_i)}
+
   json x
 end
 
@@ -330,7 +328,9 @@ post "/halt" do
 end
 
 get "/pid" do
-  JSON.generate({puma: master_pid, pid: Process.pid})
+  pretty = params.key? :pretty
+
+  json({puma: master_pid, pid: Process.pid}, pretty:)
 end
 
 get "/token" do
@@ -339,23 +339,27 @@ get "/token" do
   expires_at = Time.at(exp).to_datetime
   token = JWT.encode payload, JWT_SECRET, "HS256"
   x = {token: token, expires_at: expires_at}
+
   json x
 end
 
 get "/token/validate" do
   token = req_headers["authorization"].split[1]
   payload = JWT.decode token, JWT_SECRET, true, algorithm: "HS256"
+
   json payload
 end
 
 post "/session" do
   session.merge! params
+
   json session.to_hash
 end
 
 get "/session" do
   j = session.to_hash
   j[:hostname] = ENV["HOSTNAME"]
+
   json j
 end