Sample project using scala 3 (3.4.2), zio 2 (2.1.1), zio-http (3.0.0-RC7) to highlight a very weird problem when enabling response compression and serving static content using the Handlers.fromFile function.
The sample application is serving the static file located into src/main/resources/static folder on two separate paths:
When hitting the first URL, the application uses Middleware.serveResources to process the request, while the second URL lets the application use Middleware.serveDirectory method.
Dumping both responses with curl, they look identical:
% curl -v http://localhost:8080/resources/static/index.html
* Host localhost:8080 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
* Trying [::1]:8080...
* Connected to localhost (::1) port 8080
> GET /resources/static/index.html HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/8.6.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html
< date: Sun, 19 May 2024 17:38:25 GMT
< content-length: 130
<
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Page Title</title>
</head>
<body>
<h1>Hello!</h1>
</body>
* Connection #0 to host localhost left intact
</html>%
% curl -v http://localhost:8080/directory/static/index.html
* Host localhost:8080 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
* Trying [::1]:8080...
* Connected to localhost (::1) port 8080
> GET /directory/static/index.html HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/8.6.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-type: text/html
< date: Sun, 19 May 2024 17:37:13 GMT
< content-length: 130
<
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Page Title</title>
</head>
<body>
<h1>Hello!</h1>
</body>
* Connection #0 to host localhost left intact
</html>%
But using a regular browser only the first URL works correctly, while trying to access the second URL the brwoser reports the following error:
Content Encoding Error The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.
If response compression is disabled (it's enough to comment out Mail.scala#L14), both URLs work correctly when accessed with a browser.