#function-linear-gradient-no-nonstandard-direction

Disallow direction values in linear-gradient() calls that are not valid according to the standard syntax.

根据标准语法，禁止 linear-gradient() 中无效的方向值。

.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:

一个有效和标准的方向值是下列值其中之一：

• an angle
• 角度
• to plus a side-or-corner (to top, to bottom, to left, to right; to top right, to right top, to bottom left, etc.)
• to 加边或拐角 (to top，to bottom，to left，to right；to top right，to right top，to bottom left 等)

A common mistake (matching outdated non-standard syntax) is to use just a side-or-corner without the preceding to.

一个常见的错误(匹配过时的非标准语法)是在边或拐角之前缺少 to。

#Options

#true

The following patterns are considered warnings:

以下模式被认为是个警告：

.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 warnings:

以下模式正常：

.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); }