Use DOMMatrix to parse CSS transforms.

[mbostock]

No description provided.

[Fil]

tested under node (v10.16.3 and v14.4.0) I get this error

yarn test
/Users/fil/Sites/d3/d3-interpolate/src/transform/parse.js
6:64 error 'WebKitCSSMatrix' is not defined no-undef

In node WebKitCSSMatrix and DOMMatrix aren't defined; it's not a loss, since the current strategy using document.createElement doesn't work either (it just doesn't break any test, because this function is not tested).

We could import node-canvas@2, which has DOMMatrix, but parsing CSS transforms is not yet implemented (Automattic/node-canvas#1313).

So, in the meantime, we will need to eslint-disable no-undef that line.

[Fil]

For reference, fixes #57

[Fil]

Here is a case where this crashes:

d3.interpolateTransformCss( "translateY(12px) scale(2)", "translateX(3em) rotate(5deg)");

now throws SyntaxError: Failed to construct 'DOMMatrix': Lengths must be absolute, not relative

(changing translateX(3em) to an absolute length works)