Use rake to build generated code

Rakefile

@@ -0,0 +1,10 @@
+require "erb"
+
+rule '.go' => '.go.erb' do |task|
+  erb = ERB.new(File.read(task.source))
+  File.write(task.name, "// Do not edit. Generated from #{task.source}\n" + erb.result(binding))
+  sh "goimports", "-w", task.name
+end
+
+desc "Generate code"
+task generate: ["pgtype/int_scan_plans.go"]

pgtype/int_scan_plans.go

@@ -1,3 +1,4 @@
+// Do not edit. Generated from pgtype/int_scan_plans.go.erb
 package pgtype
 
 import (