From 2589aaa14366ae51705ef58bcf02265a0b076fbd Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@oriontransfer.co.nz>
Date: Tue, 1 Jul 2025 13:32:51 +1200
Subject: [PATCH] Allow non-string value in `Headers#[]=`.

---
 lib/protocol/http/headers.rb  | 25 +++++++++++--------------
 releases.md                   |  1 +
 test/protocol/http/headers.rb | 23 +++++++++++++++--------
 3 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/lib/protocol/http/headers.rb b/lib/protocol/http/headers.rb
index 4bce8b9..2080353 100644
--- a/lib/protocol/http/headers.rb
+++ b/lib/protocol/http/headers.rb
@@ -198,9 +198,18 @@ def extract(keys)
 			# @parameter key [String] the header key.
 			# @parameter value [String] the header value to assign.
 			def add(key, value)
-				self[key] = value
+				# The value MUST be a string, so we convert it to a string to prevent errors later on.
+				value = value.to_s
+				
+				if @indexed
+					merge_into(@indexed, key.downcase, value)
+				end
+				
+				@fields << [key, value]
 			end
 			
+			alias []= add
+			
 			# Set the specified header key to the specified value, replacing any existing header keys with the same name.
 			#
 			# @parameter key [String] the header key to replace.
@@ -214,7 +223,7 @@ def set(key, value)
 			# Merge the headers into this instance.
 			def merge!(headers)
 				headers.each do |key, value|
-					self[key] = value
+					self.add(key, value)
 				end
 				
 				return self
@@ -225,18 +234,6 @@ def merge(headers)
 				self.dup.merge!(headers)
 			end
 			
-			# Append the value to the given key. Some values can be appended multiple times, others can only be set once.
-			#
-			# @parameter key [String] The header key.
-			# @parameter value [String] The header value.
-			def []= key, value
-				if @indexed
-					merge_into(@indexed, key.downcase, value)
-				end
-				
-				@fields << [key, value]
-			end
-			
 			# The policy for various headers, including how they are merged and normalized.
 			POLICY = {
 				# Headers which may only be specified once:
diff --git a/releases.md b/releases.md
index 4114ea3..e8cef03 100644
--- a/releases.md
+++ b/releases.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
   - `Protocol::HTTP::Headers` now raise a `DuplicateHeaderError` when a duplicate singleton header (e.g. `content-length`) is added.
+  - `Protocol::HTTP::Headers#add` now coerces the value to a string when adding a header, ensuring consistent behaviour.
 
 ## v0.50.0
 
diff --git a/test/protocol/http/headers.rb b/test/protocol/http/headers.rb
index 2b2809b..dbb0955 100644
--- a/test/protocol/http/headers.rb
+++ b/test/protocol/http/headers.rb
@@ -167,18 +167,25 @@
 	end
 	
 	with "#[]=" do
-		it "can add field" do
+		it "can add field with a String value" do
+			headers["Content-Length"] = "1"
+			
+			expect(headers.fields.last).to be == ["Content-Length", "1"]
+			expect(headers["content-length"]).to be == "1"
+		end
+		
+		it "can add field with an Integer value" do
 			headers["Content-Length"] = 1
 			
-			expect(headers.fields.last).to be == ["Content-Length", 1]
-			expect(headers["content-length"]).to be == 1
+			expect(headers.fields.last).to be == ["Content-Length", "1"]
+			expect(headers["content-length"]).to be == "1"
 		end
 		
 		it "can add field with indexed hash" do
 			expect(headers.to_h).not.to be(:empty?)
 			
-			headers["Content-Length"] = 1
-			expect(headers["content-length"]).to be == 1
+			headers["Content-Length"] = "1"
+			expect(headers["content-length"]).to be == "1"
 		end
 	end
 	
@@ -186,8 +193,8 @@
 		it "can add field" do
 			headers.add("Content-Length", 1)
 			
-			expect(headers.fields.last).to be == ["Content-Length", 1]
-			expect(headers["content-length"]).to be == 1
+			expect(headers.fields.last).to be == ["Content-Length", "1"]
+			expect(headers["content-length"]).to be == "1"
 		end
 	end
 	
@@ -241,7 +248,7 @@
 		it "can merge content-length" do
 			headers.merge!("content-length" => 2)
 			
-			expect(headers["content-length"]).to be == 2
+			expect(headers["content-length"]).to be == "2"
 		end
 	end