function-linear-gradient-no-nonstandard-direction

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A common mistake (matching outdated non-standard syntax) is to use just a side-or-corner without the preceding to.

Options#

The following patterns are considered problems:

.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 problems:

.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); }