vweb: use Response struct for 302 response (#11245)

cmd/tools/vtest-self.v

@@ -47,6 +47,7 @@ const (
 		'vlib/vweb/tests/vweb_test.v',
 		'vlib/vweb/request_test.v',
 		'vlib/net/http/request_test.v',
+		'vlib/net/http/response_test.v',
 		'vlib/vweb/route_test.v',
 		'vlib/net/websocket/websocket_test.v',
 		'vlib/crypto/rand/crypto_rand_read_test.v',
@@ -89,6 +90,7 @@ const (
 		'vlib/net/http/http_httpbin_test.v',
 		'vlib/net/http/header_test.v',
 		'vlib/net/http/server_test.v',
+		'vlib/net/http/response_test.v',
 	]
 	skip_on_linux                 = [
 		'do_not_remove',

vlib/net/http/response_test.v

@@ -0,0 +1,36 @@
+module http
+
+fn test_response_bytestr() ? {
+	{
+		resp := new_response(
+			status: .ok
+			text: 'Foo'
+		)
+		assert resp.bytestr() == 'HTTP/1.1 200 OK\r\n' + 'Content-Length: 3\r\n' + '\r\n' + 'Foo'
+	}
+	{
+		resp := new_response(
+			status: .found
+			text: 'Foo'
+			header: new_header(key: .location, value: '/')
+		)
+		lines := resp.bytestr().split_into_lines()
+		assert lines[0] == 'HTTP/1.1 302 Found'
+		// header order is not guaranteed
+		check_headers(['Location: /', 'Content-Length: 3'], lines[1..3]) ?
+		assert lines[3] == ''
+		assert lines[4] == 'Foo'
+	}
+}
+
+// check_headers is a helper function for asserting all expected headers
+// are found because rendered header order is not guaranteed. The check
+// is O(n^2) which is fine for small lists.
+fn check_headers(expected []string, found []string) ? {
+	assert expected.len == found.len
+	for header in expected {
+		if !found.contains(header) {
+			return error('expected header "$header" not in $found')
+		}
+	}
+}

vlib/vweb/vweb.v

@@ -17,6 +17,11 @@ pub const (
 		http.CommonHeader.connection.str(): 'close'
 	}) or { panic('should never fail') }
 
+	http_302          = http.new_response(
+		status: .found
+		text: '302 Found'
+		header: headers_close
+	)
 	http_400          = http.new_response(
 		status: .bad_request
 		text: '400 Bad Request'
@@ -246,9 +251,10 @@ pub fn (mut ctx Context) redirect(url string) Result {
 		return Result{}
 	}
 	ctx.done = true
-	send_string(mut ctx.conn, 'HTTP/1.1 302 Found\r\nLocation: $url\r\n$ctx.header\r\n$vweb.headers_close\r\n') or {
+	mut resp := vweb.http_302
-		return Result{}
+	resp.header = resp.header.join(ctx.header)
-	}
+	resp.header.add(.location, url)
+	send_string(mut ctx.conn, resp.bytestr()) or { return Result{} }
 	return Result{}
 }