Drop the dependency on webrick

It made sense to use these utils when they were part of the stdlib
but now it's a bit silly to pull a whole webserver for 5 lines of code.

Author: byroot

Gemfile.lock

@@ -5,7 +5,6 @@ PATH
       activeresource (>= 4.1.0, < 6.0.0)
       graphql-client
       rack
-      webrick
 
 GEM
   remote: https://rubygems.org/
@@ -130,7 +129,6 @@ GEM
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    webrick (1.7.0)
     zeitwerk (2.3.0)
 
 PLATFORMS

lib/shopify_api/hmac_params.rb

@@ -1,23 +1,33 @@
 # frozen_string_literal: true
-require 'webrick/httputils'
 
 module ShopifyAPI
   module HmacParams
-    extend WEBrick::HTTPUtils
+    class << self
+      def encode(params)
+        params
+          .except(:signature, :hmac, :action, :controller)
+          .map { |k,v| sprintf("%s=%s", encode_key(k), encode_value(v)) }
+          .sort.join("&")
+      end
 
-    def self.encode(params)
-      params
-        .except(:signature, :hmac, :action, :controller)
-        .map { |k,v| sprintf("%s=%s", encode_key(k), encode_value(v)) }
-        .sort.join("&")
-    end
+      KEY_REGEXP = /([#{Regexp.escape("&=%")}])/n
+      def encode_key(key)
+        _escape(key.to_s, KEY_REGEXP)
+      end
 
-    def self.encode_key(key)
-      _escape(key.to_s, _make_regex('&=%'))
-    end
+      VALUE_REGEXP = /([#{Regexp.escape("&%")}])/n
+      def encode_value(value)
+        _escape(value.to_s, VALUE_REGEXP)
+      end
+
+      private
 
-    def self.encode_value(value)
-      _escape(value.to_s, _make_regex('&%'))
+      def _escape(str, regex)
+        str = str.b
+        str.gsub!(regex) {"%%%02X" % $1.ord}
+        # %-escaped string should contain US-ASCII only
+        str.force_encoding(Encoding::US_ASCII)
+      end
     end
   end
 end

shopify_api.gemspec

@@ -35,7 +35,6 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency("activeresource", ">= 4.1.0", "< 6.0.0")
   s.add_runtime_dependency("rack")
   s.add_runtime_dependency("graphql-client")
-  s.add_runtime_dependency("webrick")
 
   s.add_development_dependency("mocha", ">= 1.4.0")
   s.add_development_dependency("webmock")