Normalize angle range

Author: ai

lib/hacks/gradient.coffee

@@ -3,6 +3,7 @@ Value    = require('../value')
 utils    = require('../utils')
 
 parser = require('postcss-value-parser')
+range  = require('normalize-range');
 list   = require('postcss/lib/list')
 
 isDirection = /top|left|right|bottom/gi
@@ -74,6 +75,10 @@ class Gradient extends Value
       nodes[0].value = @normalizeUnit(nodes[0].value, 2)
     else if /-?\d+(.\d+)?turn/.test(nodes[0].value)
       nodes[0].value = @normalizeUnit(nodes[0].value, 1)
+    else if nodes[0].value.indexOf('deg') != -1
+      num = parseFloat(nodes[0].value)
+      num = range.wrap(0, 360, num)
+      nodes[0].value = "#{num}deg"
 
     if nodes[0].value == '0deg'
       nodes = @replaceFirst(nodes, 'to', ' ', 'top')

package.json

@@ -14,6 +14,7 @@
   "repository": "postcss/autoprefixer",
   "dependencies": {
     "postcss-value-parser": "^3.2.3",
+    "normalize-range":      "^0.1.2",
     "coffee-script":        "1.10.0",
     "num2fraction":         "^1.2.2",
     "browserslist":         "~1.0.1",

test/cases/gradient.css

@@ -80,3 +80,7 @@ div {
 .turn {
     background: linear-gradient(0.3turn, white, black);
 }
+
+.norm {
+    background: linear-gradient(-90deg, white, black);
+}

test/cases/gradient.out.css

@@ -138,3 +138,10 @@ div {
     background: -o-linear-gradient(342deg, white, black);
     background: linear-gradient(0.3turn, white, black);
 }
+
+.norm {
+    background: -webkit-gradient(linear, right top, left top, from(white), to(black));
+    background: -webkit-linear-gradient(right, white, black);
+    background: -o-linear-gradient(right, white, black);
+    background: linear-gradient(-90deg, white, black);
+}