From ed37eca2cf9dd99714f890bc64d272443c73674f Mon Sep 17 00:00:00 2001
From: Konstantin Burkalev <KSDaemon@gmail.com>
Date: Tue, 5 Sep 2023 22:51:59 +0300
Subject: [PATCH] Added tests for subprotocol selection

---
 server_test.go | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/server_test.go b/server_test.go
index 5804be1..0c341ac 100644
--- a/server_test.go
+++ b/server_test.go
@@ -54,6 +54,36 @@ func TestIsWebSocketUpgrade(t *testing.T) {
 	}
 }
 
+func TestSubProtocolSelection(t *testing.T) {
+	upgrader := Upgrader{
+		Subprotocols: []string{"foo", "bar", "baz"},
+	}
+
+	r := http.Request{Header: http.Header{"Sec-Websocket-Protocol": {"foo", "bar"}}}
+	s := upgrader.selectSubprotocol(&r, nil)
+	if s != "foo" {
+		t.Errorf("Upgrader.selectSubprotocol returned %v, want %v", s, "foo")
+	}
+
+	r = http.Request{Header: http.Header{"Sec-Websocket-Protocol": {"bar", "foo"}}}
+	s = upgrader.selectSubprotocol(&r, nil)
+	if s != "bar" {
+		t.Errorf("Upgrader.selectSubprotocol returned %v, want %v", s, "bar")
+	}
+
+	r = http.Request{Header: http.Header{"Sec-Websocket-Protocol": {"baz"}}}
+	s = upgrader.selectSubprotocol(&r, nil)
+	if s != "baz" {
+		t.Errorf("Upgrader.selectSubprotocol returned %v, want %v", s, "baz")
+	}
+
+	r = http.Request{Header: http.Header{"Sec-Websocket-Protocol": {"quux"}}}
+	s = upgrader.selectSubprotocol(&r, nil)
+	if s != "" {
+		t.Errorf("Upgrader.selectSubprotocol returned %v, want %v", s, "empty string")
+	}
+}
+
 var checkSameOriginTests = []struct {
 	ok bool
 	r  *http.Request