Create ActiveMethod::Util

Author: hoppergee

lib/active_method/util.rb

@@ -0,0 +1,43 @@
+module ActiveMethod
+  module Util
+    module_function
+
+    def constantize(klass, name)
+      constant = klass.const_get(name) rescue nil
+      return constant unless constant.nil?
+
+      namespaces_of(klass).each do |namespace|
+        constant = namespace.const_get(name) rescue nil
+        return constant unless constant.nil?
+      end
+
+      raise NameError.new("wrong constant name #{name}") if constant.nil?
+    end
+
+    def namespaces_of(klass)
+      namespaces = []
+
+      names = klass.name.split("::")
+      names.pop
+      while !names.empty?
+        namespaces << Object.const_get(names.join("::"))
+        names.pop
+      end
+
+      namespaces
+    end
+
+    def camel_case(str)
+      str = str.to_s
+      return str if str !~ /_/ && str =~ /[A-Z]+.*/
+      str.split("_").map(&:capitalize).join
+    end
+
+    def snake_case(str)
+      return str.downcase if str =~ /^[A-Z_]+$/
+      str.gsub(/\B[A-Z]/, '_\&').squeeze("_") =~ /_*(.*)/
+      $+.downcase
+    end
+
+  end
+end

test/active_method/test_util.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class TestUtil < ApplicationTest
+
+  it "constantize - raise error on missing constant" do
+    error = assert_raises NameError do
+      ActiveMethod::Util.constantize(Object, 'WrongName')
+    end
+
+    assert_includes error.message, "wrong constant name WrongName"
+  end
+
+end