added streaming plugin tests

test/http_test.rb

@@ -26,6 +26,7 @@ class HTTPTest < Minitest::Test
   include Plugins::Multipart
   include Plugins::Expect
   include Plugins::RateLimiter
+  include Plugins::Stream
 
   def test_verbose_log
     log = StringIO.new

test/https_test.rb

@@ -27,6 +27,7 @@ class HTTPSTest < Minitest::Test
   include Plugins::Expect
   include Plugins::RateLimiter
   include Plugins::Persistent unless RUBY_ENGINE == "jruby" || RUBY_VERSION < "2.3"
+  include Plugins::Stream
 
   def test_connection_coalescing
     coalesced_origin = "https://#{ENV["HTTPBIN_COALESCING_HOST"]}"

test/support/requests/plugins/stream.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Requests
+  module Plugins
+    module Stream
+      def test_plugin_stream
+        session = HTTPX.plugin(RequestInspector).plugin(:stream)
+
+        uri = build_uri("/get")
+
+        no_stream_response = session.get(uri)
+        stream_response = session.get(uri, stream: true)
+
+        assert session.total_responses.size == 1, "there should be an available response"
+
+        assert no_stream_response.body.to_s == stream_response.body.to_s, "content should be the same"
+
+        assert session.total_responses.size == 2, "there should be 2 available responses"
+      end
+
+      def test_plugin_stream_multiple_responses_error
+        session = HTTPX.plugin(:stream)
+
+        assert_raises(HTTPX::Error, /support only 1 response at a time/) do
+          session.get(build_uri("/stream/2"), build_uri("/stream/3"), stream: true)
+        end
+      end
+
+      def test_plugin_stream_each_line
+        session = HTTPX.plugin(:stream)
+
+        response = session.get(build_uri("/stream/3"), stream: true)
+        lines = response.each_line.each_with_index.map do |line, idx|
+          data = JSON.parse(line)
+          assert data["id"] == idx
+        end
+
+        assert lines.size == 3, "all the lines should have been yielded"
+      end
+    end
+  end
+end