Added viewport support and defered execution on gopherjs serve (#860)

AnikHasibul · hajimehoshi · commit bf5fc7d38140 · 2018-10-03T14:27:33.000+09:00
Added `&lt;meta name="viewport" content="initial-scale=1"&gt;` for responsive web development 
environment with gopherjs via gopherjs serve command.
diff --git a/tool.go b/tool.go
@@ -641,7 +641,15 @@ func (fs serveCommandFileSystem) Open(requestName string) (http.File, error) {
 
 	if isIndex {
 		// If there was no index.html file in any dirs, supply our own.
-		return newFakeFile("index.html", []byte(`<html><head><meta charset="utf-8"><script src="`+base+`.js"></script></head><body></body></html>`)), nil
+		return newFakeFile("index.html", []byte(`<html>
+<head>
+	<meta name="viewport" content="initial-scale=1">
+	<meta charset="utf-8">
+	<script defer src="`+base+`.js"></script>
+</head>
+<body>
+</body>
+</html>`)), nil
 	}
 
 	return nil, os.ErrNotExist
