1261275 - Animation easing 'step-middle' not accepted

Status: RESOLVED DUPLICATE of bug 1248340

(Core :: DOM: Animation, defect)

Description

[suzyh]

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.110 Safari/537.36

Steps to reproduce:

In Firefox Nightly (48.0a1 2016-03-31) console:

> var e = 'steps(3, middle)'
> document.documentElement.animate([], {easing: e}).effect.timing.easing

Also tried with
e = 'steps(3, end)'
e = 'step-middle'
e = 'step-end'


Actual results:

For 'steps(3, end)' and 'step-end', the output is the same as e.
For 'steps(3, middle)' and 'step-middle', the output is "TypeError: Invalid easing."


Expected results:

The output should be the same as e for all four cases, as in Chromium (with Experimental Web Platform features enabled).

'steps(x, middle)' and 'step-middle' are valid easings according to the Web Animations spec: http://w3c.github.io/web-animations/#timing-in-discrete-steps

Comment 1

[Brian Birtles (:birtles, Feb 26~ parental leave)]

steps-middle is going to be removed from the spec. We actually implemented it in bug 1248340 but didn't land it because the spec discussions around that leaded to the conclusion we should spec a frames() function instead and implement that.

Comment 2

[Brian Birtles (:birtles, Feb 26~ parental leave)]

I'm going to dupe this to bug 1248340 since that bug is the new step-middle.