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The Mozilla Remote Reftest Extension

This is a Firefox extension which allows someone to run Mozilla reftests against tests hosted on a remote server. This can be useful when testing Firefox on devices which, due to various limitations, don’t allow reftest to operate in its traditional localhost mode.

Running remote reftests

First, you’ll need a copy of Mozilla’s JS-based HTTP server (httpd.js) running on a machine to host the reftests you want to run. The version of httpd.js which is in mozilla-central won’t quite do, as that version is hardcoded to only serve files from http://localhost, and it doesn’t know about some of the file extensions which are relevant to reftest (such as the reftest manifest .list files). I’ve included a modified version which works with remote reftest in the “httpd” directory. Copy the files to the directory containing the reftests you wish to serve, then launch it with this command-line:

/path/to/xpcshell -v 170 -f httpd.js server.js [your.ip.address]

If you omit your.ip.address, the server will only serve files from http://localhost:8888/, which isn’t very useful for running reftests remotely. Otherwise, the files will be served from http://your.ip.address:8888/

Next, install remotereftest.xpi in Firefox on the test machine, and launch the tool by choosing “Remote Reftest Tool” from Firefox’s Tools menu. An HTML page will appear with the reftest options:

1. manifest url – enter the http:// url of the reftest manifest .list file you’d like to run
2. starting test – enter the test number you want to start at; this is useful in case your test run always crashes at test X
3. chunk size – enter the number of tests you’d like to run per sequence; the reftest test window is closed and then reopened between sequences. It appears to be necessary to “chunk” the test run like this on devices with limited memory, in order to avoid specious crashes. Firefox on desktop OS’s can run all the tests in a single sequence.

After you start the test, you can see the last 10 lines of the log in the window, as well as a summary of results. The complete results are written to a file called results.log in the directory where the extension is located.