Add a way to get latest version of an xsd schema by prefix

app/lib/xsd_util.rb

@@ -0,0 +1,36 @@
+class XsdUtil
+  SCHEMA_PATH = 'lib/schemas/'.freeze
+
+  def initialise(schema_path = SCHEMA_PATH)
+    @schema_path = schema_path
+  end
+
+  def xsd_schemas
+    @xsd_schemas ||= Dir.entries(SCHEMA_PATH)
+                        .select { |f| File.file? File.join(SCHEMA_PATH, f) }
+  end
+
+  def basename(filename)
+    File.basename(filename, '.xsd')
+  end
+
+  def prefix(filename)
+    regex = /([a-zA-Z]+-?[a-zA-Z]+)/
+
+    basename(filename).match(regex)[0]
+  end
+
+  def prefixes
+    xsd_schemas.map { |filename| prefix(filename) }.uniq
+  end
+
+  def schemas_by_name
+    prefixes.each_with_object({}) do |prefix, hash|
+      hash[prefix] = xsd_schemas.select { |filename| filename.include? prefix }.uniq.sort
+    end
+  end
+
+  def latest(prefix)
+    schemas_by_name[prefix].last
+  end
+end