(maint) make transports register more robust

Lifting all `@transports` accesses into a single method simplifies
the code's internal structure (see Law of Demeter).

Author: DavidS

lib/puppet/resource_api/transport.rb

@@ -9,21 +9,19 @@ def register(schema)
     raise Puppet::DevError, 'requires `:connection_info`' unless schema.key? :connection_info
     raise Puppet::DevError, '`:connection_info` must be a hash, not `%{other_type}`' % { other_type: schema[:connection_info].class } unless schema[:connection_info].is_a?(Hash)
 
-    init_transports
-    unless @transports[current_environment][schema[:name]].nil?
+    unless transports[schema[:name]].nil?
       raise Puppet::DevError, 'Transport `%{name}` is already registered for `%{environment}`' % {
         name: schema[:name],
         environment: current_environment,
       }
     end
-    @transports[current_environment][schema[:name]] = Puppet::ResourceApi::TransportSchemaDef.new(schema)
+    transports[schema[:name]] = Puppet::ResourceApi::TransportSchemaDef.new(schema)
   end
   module_function :register # rubocop:disable Style/AccessModifierDeclarations
 
   # retrieve a Hash of transport schemas, keyed by their name.
   def list
-    init_transports
-    Marshal.load(Marshal.dump(@transports[current_environment]))
+    Marshal.load(Marshal.dump(transports))
   end
   module_function :list # rubocop:disable Style/AccessModifierDeclarations
 
@@ -47,9 +45,8 @@ def inject_device(name, transport)
   module_function :inject_device # rubocop:disable Style/AccessModifierDeclarations
 
   def self.validate(name, connection_info)
-    init_transports
-    require "puppet/transport/schema/#{name}" unless @transports[current_environment].key? name
-    transport_schema = @transports[current_environment][name]
+    require "puppet/transport/schema/#{name}" unless transports.key? name
+    transport_schema = transports[name]
     if transport_schema.nil?
       raise Puppet::DevError, 'Transport for `%{target}` not registered with `%{environment}`' % {
         target: name,
@@ -64,18 +61,12 @@ def self.validate(name, connection_info)
 
   def self.get_context(name)
     require 'puppet/resource_api/puppet_context'
-    Puppet::ResourceApi::PuppetContext.new(@transports[current_environment][name])
+    Puppet::ResourceApi::PuppetContext.new(transports[name])
   end
   private_class_method :get_context
 
-  def self.init_transports
-    @transports ||= {}
-    @transports[current_environment] ||= {}
-  end
-  private_class_method :init_transports
-
   def self.wrap_sensitive(name, connection_info)
-    transport_schema = @transports[current_environment][name]
+    transport_schema = transports[name]
     if transport_schema
       transport_schema.definition[:connection_info].each do |attr_name, options|
         if options.key?(:sensitive) && (options[:sensitive] == true) && connection_info.key?(attr_name)
@@ -87,6 +78,12 @@ def self.wrap_sensitive(name, connection_info)
   end
   private_class_method :wrap_sensitive
 
+  def self.transports
+    @transports ||= {}
+    @transports[current_environment] ||= {}
+  end
+  private_class_method :transports
+
   def self.current_environment
     if Puppet.respond_to? :lookup
       env = Puppet.lookup(:current_environment)

spec/puppet/resource_api/transport_spec.rb

@@ -312,28 +312,6 @@ class Wibble; end
     end
   end
 
-  describe '#init_transports' do
-    context 'when there is not a current_environment' do
-      it 'will return the default transport environment name' do
-        change_environment
-
-        described_class.send :init_transports
-
-        expect(described_class.instance_variable_get(:@environment)).to eq(:transports_default)
-      end
-    end
-
-    context 'when there is a current_environment' do
-      it 'will return the set environment name' do
-        change_environment(:something)
-
-        described_class.send :init_transports
-
-        expect(described_class.instance_variable_get(:@environment)).to eq(:something)
-      end
-    end
-  end
-
   describe '#wrap_sensitive(name, connection_info)' do
     let(:schema) do
       {