Map canonical names and aliases in a schema

core/lib/rom/schema.rb

@@ -430,6 +430,17 @@ def to_ast
       [:schema, [name, attributes.map(&:to_ast)]]
     end
 
+    # Hash from canonical name to alias for aliased attributes
+    #
+    # @return [Hash<Symbol, Symbol>]
+    #
+    # @api public
+    def alias_mapping
+      each_with_object({}) do |attr, obj|
+        obj[attr.name] = attr.alias if attr.aliased?
+      end
+    end
+
     # @api private
     def set!(key, value)
       instance_variable_set("@#{ key }", value)

core/spec/unit/rom/schema_spec.rb

@@ -54,4 +54,13 @@
       expect(schema.project(:name).primary_key_name).to be(:id)
     end
   end
+
+  describe '#alias_mapping' do
+    it 'returns a hash from canonical name to alias including aliased attributes' do
+      attrs = { id: ROM::Types::Integer.meta(name: :id, alias: :pk), name: ROM::Types::String }
+      schema = ROM::Schema.define(:name, attributes: attrs.values)
+
+      expect(schema.alias_mapping).to eq(id: :pk)
+    end
+  end
 end