Re: Fwd: Test Changes Proposal

On Tue, 14 Feb 2017 08:41:15 +0100, Benjamin Schaaf <>  

> ---------- Forwarded message ----------
> From: Benjamin Schaaf <>
> Date: Tue, Feb 14, 2017 at 12:48 PM
> Subject: Test Changes Proposal
> To: David Singer <>, Simon Pieters <>,
> Silvia Pfeiffer <>
> Hello,
> I've put together a proposal for a way to reorganise webvtt's
> web-platform-tests to make writing and reading tests easier as well as
> add categorization.
> I'd like to get input on this before I start working on it.
> Thanks,
> Benjamin Schaaf
> # WebVTT web-platform-tests changes proposal
> A lot of the way tests are currently set up is limited in some manner,  
> eg.
> `webvtt-file-parsing tests` can only check direct attributes of webvtt  
> cues and
> the number of cues generated. Instead of building on top of the current  
> tests,
> I'd like to rewrite the way the current tests are run so we can more  
> easily
> write tests.
> For `webvtt-file-parsing` I'd like to generate tests from a template that
> includes a wevtt file and some js assertions given the video object.

This sounds OK.

> For `webvtt-cue-text-parsing-rules` I'd like to change the format to be  
> more
> easily readable and clean up (or rewrite).

The format in the .dat files are the same as the tree-builder tests in  
html5lib-test, which are used for testing the HTML parser. But I'm  
certainly open for using something else here.

> I think the api tests are generally fine as they are (in terms of the  
> way tests
> are run).
> I haven't dived deep enough into rendering tests to come up with anything
> concrete, but there should be a nice way to combine a webvtt file, the  
> test file
> and a ref file into a more easily writeable/readable single-file format  
> that we
> can generate the rest from.

Yes, there is room for improvement in the rendering tests, but also some  
challenges that I'm not sure how to address. In particular the  
specification allows for a UA-defined margin (to dodge overscan or just to  
make it look better), but the tests do not account for this. Also Safari  
has quite different default rendering than what the specification  
requires. Chromium also has some default padding on the cue background  
box, I think, which causes many tests to fail.

> ## Directory Structure
> I'd also like to clean up the directory structure. I'm not sure if any  
> deeper
> directories are needed
> webvtt/
>   api/
>     VTTCue/
>     VTTRegion/
>   parsing/
>     file-parsing/
>     cue-text-parsing/
>   rendering/
>     TBD

As James said this will result in some work for vendors to update test  
expectations, but I think many tests need some updates anyway and there is  
missing coverage, that we can do this.

There is some documentation about directory structure, though the  
documentation itself is in the process of being moved...

Old docs:

New docs (will soon stop existing at this location per gsnedders):

> ## Categorization
> I propose we categorize tests by keeping track of the category of a test
> separately (eg. in a `categories.json` file). We can then use the json  
> output of
> the test runner to parse which categories/parts of the spec are well  
> supported.
> The tests for `2dcontext` do something similar.

`<link rel="help" href="(spec link with fragid)">` in each test is a way  
in web-platform-tests to provide a mapping to which section of which spec  
a test is testing. (And fallback to directory structure; I think the ideas  
is that first directory somehow maps to some spec and the last directory  
maps to an id within that spec.)

Is a categories.json file still helpful if there are <link>s?

Thank you!
Simon Pieters
Opera Software

Received on Wednesday, 15 February 2017 12:24:13 UTC