Add test for post with explicit content-length header.

Author: ioquatix

test/async/http/faraday/adapter/post.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2024-2025, by Samuel Williams.
+
+require "async/http/faraday"
+
+require "sus/fixtures/async/reactor_context"
+require "sus/fixtures/async/http/server_context"
+
+describe Async::HTTP::Faraday::Adapter do
+	with "a local http server" do
+		include Sus::Fixtures::Async::ReactorContext
+		include Sus::Fixtures::Async::HTTP::ServerContext
+		
+		let(:app) do
+			Protocol::HTTP::Middleware.for do |request|
+				Protocol::HTTP::Response[200, {}, request.body]
+			end
+		end
+		
+		with "explicit content-length" do
+			it "client can post resource" do
+				adapter = Faraday.new(bound_url) do |builder|
+					builder.adapter :async_http
+				end
+				
+				# We test for this case, because Faraday used to add `content-length` header automatically, causing duplicate headers. The adapter explicitly handles this case now, extracting `content-length` from the request headers and passing it into the body wrapper.
+				response = adapter.post("/index", "Hello World", {"content-type" => "text/plain", "content-length" => "11"})
+				expect(response.body).to be == "Hello World"
+			ensure
+				adapter&.close
+			end
+		end
+	end
+end