Disallow direction values in linear-gradient()
calls that are not valid according to the
standard syntax.
.foo { background: linear-gradient(to top, #fff, #000); }
/** ↑
* This (optional) first argument is the "direction" */
A valid and standard direction value is one of the following:
- an angle
to
plus a side-or-corner (to top
,to bottom
,to left
,to right
;to top right
,to right top
,to bottom left
, etc.)
A common mistake (matching outdated non-standard syntax) is to use just a side-or-corner without the preceding to
.
The following patterns are considered violations:
.foo { background: linear-gradient(top, #fff, #000); }
.foo { background: linear-gradient(bottom, #fff, #000); }
.foo { background: linear-gradient(left, #fff, #000); }
.foo { background: linear-gradient(45, #fff, #000); }
.foo { background: linear-gradient(to top top, #fff, #000); }
The following patterns are not considered violations:
.foo { background: linear-gradient(to top, #fff, #000); }
.foo { background: linear-gradient(to bottom right, #fff, #000); }
.foo { background: linear-gradient(45deg, #fff, #000); }
.foo { background: linear-gradient(1.57rad, #fff, #000); }
/* Direction defaults to "to bottom" */
.foo { background: linear-gradient(#fff, #000); }