Advanced Testing Features

Certain test scenarios require more than just static HTML generation. This is supported through the wptserve server, and controlled by file name flags. Several scenarios in particular are common:

Tests Involving Multiple Origins

Our test servers are guaranteed to be accessible through two domains and five subdomains under each. The ‘main’ domain is unnamed; the other is called ‘alt’. These subdomains are: www, www1, www2, 天気の良い日, and élève; there is also nonexistent which is guaranteed not to resolve. In addition, the HTTP server listens on two ports, and the WebSockets server on one. These subdomains and ports must be used for cross-origin tests.

Tests must not hardcode the hostname of the server that they expect to be running on or the port numbers, as these are not guaranteed by the test environment. Instead they can get this information in one of two ways:

  • From script, using the location API.

  • By using a textual substitution feature of the server.

In order for the latter to work, a file must either have a name of the form {name}.sub.{ext} e.g. example-test.sub.html or be referenced through a URL containing pipe=sub in the query string e.g. example-test.html?pipe=sub. The substitution syntax uses {{ }} to delimit items for substitution. For example to substitute in the main host name, one would write: {{host}}.

To get full domains, including subdomains, there is the hosts dictionary, where the first dimension is the name of the domain, and the second the subdomain. For example, {{hosts[][www]}} would give the www subdomain under the main (unnamed) domain, and {{hosts[alt][élève]}} would give the élève subdomain under the alt domain.

For mostly historic reasons, the subdomains of the main domain are also available under the domains dictionary; this is identical to hosts[].

Ports are also available on a per-protocol basis. For example, {{ports[ws][0]}} is replaced with the first (and only) WebSockets port, while {{ports[http][1]}} is replaced with the second HTTP port.

The request URL itself can be used as part of the substitution using the location dictionary, which has entries matching the window.location API. For example, {{location[host]}}is replaced by hostname:port for the current request, matching

Tests Requiring Special Headers

For tests requiring that a certain HTTP header is set to some static value, a file with the same path as the test file except for an an additional .headers suffix may be created. For example for /example/test.html, the headers file would be /example/test.html.headers. This file consists of lines of the form

header-name: header-value

For example

Content-Type: text/html; charset=big5

To apply the same headers to all files in a directory use a __dir__.headers file. This will only apply to the immediate directory and not subdirectories.

Headers files may be used in combination with substitutions by naming the file e.g. test.html.sub.headers.

Tests Requiring Full Control Over The HTTP Response

For full control over the request and response the server provides the ability to write .asis files; these are served as literal HTTP responses. It also provides the ability to write Python scripts that have access to request data and can manipulate the content and timing of the response. For details see the wptserve documentation.

Writing tests for HTTP/2.0

The server now has a prototype HTTP/2.0 server which gives you access to some of the HTTP/2.0 specific functionality. Currently, the server is off by default and needs to be run using ./wpt serve --h2 in order to enable it. The HTTP/2.0 server supports handlers that work per-frame; these, along with the API are documented in Writing H2 Tests

Important: The HTTP/2.0 server requires you to have Python 2.7.10+ and OpenSSL 1.0.2+. This is because HTTP/2.0 is negotiated using the TLS ALPN extension, which is only supported in OpenSSL 1.0.2 and up.