Add support for additional derived components

@target-uri, @scheme, @request-target, @query and @query-param.

CHANGELOG.md

@@ -1,5 +1,10 @@
 ## [Unreleased]
 
+## [0.5.1] - 2024-04-01
+
+- Add support for additional derived components:
+  @target-uri, @scheme, @request-target, @query and @query-param.
+
 ## [0.5.0] - 2024-03-30
 
 - Build Linzer::Message instances from Rack request and response objects

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    linzer (0.5.0)
+    linzer (0.5.1)
       ed25519 (~> 1.3, >= 1.3.0)
       rack (~> 3.0)
       starry (~> 0.1)

lib/linzer/message.rb

@@ -25,20 +25,33 @@ def field?(f)
       !!self[f]
     end
 
+    DERIVED_COMPONENT = {
+      "@method"         => :request_method,
+      "@authority"      => :authority,
+      "@path"           => :path_info,
+      "@status"         => :status,
+      "@target-uri"     => :url,
+      "@scheme"         => :scheme,
+      "@request-target" => :fullpath,
+      "@query"          => :query_string
+    }.freeze
+
     def [](field_name)
       if !field_name.start_with?("@")
         return @operation.env[Request.rack_header_name(field_name)] if request?
         return @operation.headers[field_name]                     # if response?
       end
 
+      method = DERIVED_COMPONENT[field_name]
+
       case field_name
-      when "@method"    then @operation.request_method
-      when "@authority" then @operation.authority
-      when "@path"      then @operation.path_info
-      when "@status"    then @operation.status
-      else # XXX: improve this and add support for all fields in the RFC
-        raise Error.new "Unknown/unsupported field: \"#{field_name}\""
+      when "@query"
+        return "?#{@operation.public_send(method)}"
+      when /\A(?<field>(?<prefix>@query-param)(?<rest>;name=.+)\Z)/
+        return parse_query_param Regexp.last_match
       end
+
+      method ? @operation.public_send(method) : nil
     end
 
     class << self
@@ -48,5 +61,17 @@ def parse_structured_dictionary(str, field_name = nil)
         raise Error.new "Cannot parse \"#{field_name}\" field. Bailing out!"
       end
     end
+
+    private
+
+    def parse_query_param(match_data)
+      raw_item    = '"%s"%s' % [match_data[:prefix], match_data[:rest]]
+      parsed_item = Starry.parse_item(raw_item)
+      fail unless parsed_item.value == "@query-param"
+      param_name  = URI.decode_uri_component(parsed_item.parameters["name"])
+      URI.encode_uri_component(@operation.params.fetch(param_name))
+    rescue => _
+      nil
+    end
   end
 end

lib/linzer/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Linzer
-  VERSION = "0.5.0"
+  VERSION = "0.5.1"
 end

spec/message_spec.rb

@@ -43,6 +43,90 @@
       expect(message["@status"]).to eq(202)
     end
 
+    it "returns the full target URI for a request" do
+      server = "www.example.org"
+      scheme = "http"
+      path = "/target/example"
+      headers = {"Host" => server}
+      request = Linzer.new_request(:get, path, {}, headers)
+      request.env["rack.url_scheme"] = scheme
+      expected_target_uri = "#{scheme}://#{server}#{path}"
+      message = described_class.new(request)
+      expect(message["@target-uri"]).to eq(expected_target_uri)
+    end
+
+    it "returns the scheme of the target URI for a request" do
+      scheme = "https"
+      path = "/target/example2"
+      request = Linzer.new_request(:get, path, {}, {})
+      request.env["rack.url_scheme"] = scheme
+      message = described_class.new(request)
+      expect(message["@scheme"]).to eq(scheme)
+    end
+
+    it "returns the request target" do
+      path = "/path"
+      request = Linzer.new_request(:post, path, {}, {})
+      query_string = "param=value"
+      request.env["QUERY_STRING"] = query_string
+      message = described_class.new(request)
+      expected_target = "#{path}?#{query_string}"
+      expect(message["@request-target"]).to eq(expected_target)
+    end
+
+    it "returns the query portion of the target URI for a request, example 1" do
+      path = "/path"
+      request = Linzer.new_request(:get, path, {}, {})
+      query_string = "param=value&foo=bar&baz=bat%2Dman"
+      request.env["QUERY_STRING"] = query_string
+      message = described_class.new(request)
+      expected_query = "?#{query_string}"
+      expect(message["@query"]).to eq(expected_query)
+    end
+
+    it "returns the query portion of the target URI for a request, example 2" do
+      path = "/path"
+      request = Linzer.new_request(:get, path, {}, {})
+      query_string = "queryString"
+      request.env["QUERY_STRING"] = query_string
+      message = described_class.new(request)
+      expected_query = "?#{query_string}"
+      expect(message["@query"]).to eq(expected_query)
+    end
+
+    it "returns the query portion of the target URI for a request, example 3" do
+      path = "/path"
+      request = Linzer.new_request(:get, path, {}, {})
+      message = described_class.new(request)
+      expected_query = "?"
+      expect(message["@query"]).to eq(expected_query)
+    end
+
+    it "returns query parameter of the request target URI" do
+      path = "/path"
+      query_string = "param=value&foo=bar&baz=batman&qux="
+      request = Linzer.new_request(:get, path, {}, {})
+      request.env["QUERY_STRING"] = query_string
+      message = described_class.new(request)
+      expect(message["@query-param;name=\"baz\""]).to    eq("batman")
+      expect(message["@query-param;name=\"qux\""]).to    eq("")
+      expect(message["@query-param;name=\"param\""]).to  eq("value")
+    end
+
+    it "returns parsed and encoded query parameter of the request target URI" do
+      path = "/parameters"
+      query_string = "var=this%20is%20a%20big%0Amultiline%20value&bar=with+plus+whitespace&fa%C3%A7ade%22%3A%20=something"
+      request = Linzer.new_request(:get, path, {}, {})
+      request.env["QUERY_STRING"] = query_string
+      message = described_class.new(request)
+      expected_var_value    = "this%20is%20a%20big%0Amultiline%20value"
+      expected_bar_value    = "with%20plus%20whitespace"
+      expected_facade_value = "something"
+      expect(message["@query-param;name=\"var\""]).to eq(expected_var_value)
+      expect(message["@query-param;name=\"bar\""]).to eq(expected_bar_value)
+      expect(message["@query-param;name=\"fa%C3%A7ade%22%3A%20\""]).to eq(expected_facade_value)
+    end
+
     it "returns null on undefined field on request" do
       request = Linzer.new_request(:put, "/bar", {}, {"x-foo" => "baz"})
       message = described_class.new(request)