More tests for quoted strings.

lib/protocol/http/header/quoted_string.rb

@@ -30,12 +30,17 @@ def self.unquote(value, normalize_whitespace = true)
 					return value
 				end
 
-				# Quote a string if required. Doesn't handle newlines correctly currently.
+				QUOTES_REQUIRED = /[()<>@,;:\\"\/\[\]?={} \t]/
+
+				# Quote a string for HTTP header values if required.
+				#
+				# @raises [ArgumentError] if the value contains invalid characters like control characters or newlines.
 				def self.quote(value, force = false)
-					if value =~ /"/ or force
-						"\"#{value.gsub(/["\\]/, "\\\\\\0")}\""
+					# Check if quoting is required:
+					if value =~ QUOTES_REQUIRED or force
+						"\"#{value.gsub(/["\\]/, '\\\\\0')}\""
 					else
-						return value
+						value
 					end
 				end
 			end

test/protocol/http/header/quoted_string.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2016-2024, by Samuel Williams.
+
+require 'protocol/http/header/quoted_string'
+
+describe Protocol::HTTP::Header::QuotedString do
+	with ".unquote" do
+		it "ignores linear whitespace" do
+			quoted_string = subject.unquote(%Q{"Hello\r\n  World"})
+
+			expect(quoted_string).to be == "Hello World"
+		end
+	end
+
+	with ".quote" do
+		it "quotes a string with a space" do
+			quoted_string = subject.quote("Hello World")
+
+			expect(quoted_string).to be == %Q{"Hello World"}
+		end
+
+		it "quotes a string with a double quote" do
+			quoted_string = subject.quote(%Q{Hello "World"})
+
+			expect(quoted_string).to be == %Q{"Hello \\"World\\""}
+		end
+
+		it "quotes a string with a backslash" do
+			quoted_string = subject.quote(%Q{Hello \\World})
+
+			expect(quoted_string).to be == %Q{"Hello \\\\World"}
+		end
+	end
+end