adding :close_handshake_timeout timeout option

used to monitor readiness of connection to write the last goaway frame from HTTP/2

lib/httpx/connection/http2.rb

@@ -73,8 +73,11 @@ module HTTPX
     end
 
     def close
-      @connection.goaway unless @connection.state == :closed
       emit(:close)
+      unless @connection.state == :closed
+        @connection.goaway
+        emit(:timeout, @options.timeout[:close_handshake_timeout])
+      end
     end
 
     def empty?

lib/httpx/options.rb

@@ -11,6 +11,7 @@ module HTTPX
     MAX_BODY_THRESHOLD_SIZE = (1 << 10) * 112 # 112K
     KEEP_ALIVE_TIMEOUT = 20
     SETTINGS_TIMEOUT = 10
+    CLOSE_HANDSHAKE_TIMEOUT = 10
     CONNECT_TIMEOUT = READ_TIMEOUT = WRITE_TIMEOUT = 60
     REQUEST_TIMEOUT = OPERATION_TIMEOUT = nil
 
@@ -39,6 +40,7 @@ module HTTPX
       :timeout => {
         connect_timeout: CONNECT_TIMEOUT,
         settings_timeout: SETTINGS_TIMEOUT,
+        close_handshake_timeout: CLOSE_HANDSHAKE_TIMEOUT,
         operation_timeout: OPERATION_TIMEOUT,
         keep_alive_timeout: KEEP_ALIVE_TIMEOUT,
         read_timeout: READ_TIMEOUT,

sig/options.rbs

@@ -9,9 +9,10 @@ module HTTPX
     OPERATION_TIMEOUT: Integer
     KEEP_ALIVE_TIMEOUT: Integer
     SETTINGS_TIMEOUT: Integer
+    CLOSE_HANDSHAKE_TIMEOUT: Integer
     DEFAULT_OPTIONS: Hash[Symbol, untyped]
 
-    type timeout_type = :connect_timeout | :settings_timeout | :operation_timeout | :keep_alive_timeout | :read_timeout | :write_timeout | :request_timeout
+    type timeout_type = :connect_timeout | :settings_timeout | :close_handshake_timeout | :operation_timeout | :keep_alive_timeout | :read_timeout | :write_timeout | :request_timeout
     type timeout = Hash[timeout_type, Numeric?]
 
     def self.new: (?options) -> instance

test/options_test.rb

@@ -80,6 +80,7 @@ class OptionsTest < Minitest::Test
       :timeout => {
         connect_timeout: 60,
         settings_timeout: 10,
+        close_handshake_timeout: 10,
         operation_timeout: nil,
         keep_alive_timeout: 20,
         read_timeout: 60,