Apply suggestions from code review

Incorporate suggestions from Adrien Thebo

Co-Authored-By: Adrien Thebo <[email protected]>

lib/r10k/source/hash.rb

@@ -126,8 +126,8 @@ class R10K::Source::Hash < R10K::Source::Base
   # @return [Boolean] False if the hash is obviously invalid. A true return
   #   means _maybe_ it's valid.
   def self.valid_environments_hash?(hash)
-      # TODO: more robust schema valiation
-      hash.is_a?(Hash)
+    # TODO: more robust schema valiation
+    hash.is_a?(Hash)
   end
 
   # @param name [String] The identifier for this source.
@@ -143,6 +143,10 @@ def initialize(name, basedir, options = {})
     super(name, basedir, options)
   end
 
+  # Set the environment hash for the source. The environment hash is what the
+  # source uses to generate enviroments.
+  # @param hash [Hash] The hash to sanitize and use as the source's environments.
+  #   Should be formatted for use with R10K::Environment#from_hash.
   def set_environments_hash(hash)
     @environments_hash = hash.reduce({}) do |memo,(name,opts)|
       R10K::Util::SymbolizeKeys.symbolize_keys!(opts)
@@ -155,8 +159,11 @@ def set_environments_hash(hash)
     end
   end
 
+  # Return the sanitized environments hash for this source. The environments
+  # hash should contain objects formatted for use with R10K::Environment#from_hash.
+  # If the hash does not exist it will be built based on @options.
   def environments_hash
-    @environments_hash ||= set_environments_hash(@options.delete(:environments) || {})
+    @environments_hash ||= set_environments_hash(@options.fetch(:environments, {}))
   end
 
   def environments