Vendor prefix

modules/__mocks__/prefix.js

@@ -0,0 +1,7 @@
+'use strict';
+
+var prefixMock = function (style) {
+  return style;
+};
+
+module.exports = prefixMock;

modules/prefix.js

@@ -0,0 +1,133 @@
+/**
+ * Based on https://github.com/jsstyles/css-vendor, but without any dash-case
+ * shenanigans.
+ */
+
+'use strict';
+
+var kebabCase = require('lodash/string/kebabCase');
+
+var jsCssMap = {
+    Webkit: '-webkit-',
+    Moz: '-moz-',
+    // IE did it wrong again ...
+    ms: '-ms-',
+    O: '-o-'
+};
+var testProp = 'Transform';
+
+var domStyle = document.createElement('p').style;
+var prefixedPropertyCache = {};
+var prefixedValueCache = {};
+var jsVendorPrefix = '';
+var cssVendorPrefix = '';
+
+for (var js in jsCssMap) {
+  if ((js + testProp) in domStyle) {
+    jsVendorPrefix = js;
+    cssVendorPrefix = jsCssMap[js];
+    break;
+  }
+}
+
+var _getPrefixedProperty = function (property) {
+  if (prefixedPropertyCache.hasOwnProperty(property)) {
+    return prefixedPropertyCache[property];
+  }
+
+  if (property in domStyle) {
+    // unprefixed
+    prefixedPropertyCache[property] = {
+      css: kebabCase(property),
+      js: property
+    };
+    return prefixedPropertyCache[property];
+  }
+
+  var newProperty =
+    jsVendorPrefix + property[0].toUpperCase() + property.slice(1);
+  if (newProperty in domStyle) {
+    // prefixed
+    prefixedPropertyCache[property] = {
+      css: cssVendorPrefix + kebabCase(property),
+      js: newProperty
+    };
+    return prefixedPropertyCache[property];
+  }
+
+  // unsupported
+  return prefixedPropertyCache[property] = false;
+};
+
+var _getPrefixedValue = function (property, value) {
+  // don't test numbers or numbers with units (e.g. 10em)
+  if (typeof value !== 'string' || !isNaN(parseInt(value, 10))) {
+    return value;
+  }
+
+  var cacheKey = property + value;
+
+  if (prefixedValueCache.hasOwnProperty(cacheKey)) {
+    return prefixedValueCache[cacheKey];
+  }
+
+  // Clear style first
+  domStyle[property] = '';
+
+  // Test value as it is.
+  domStyle[property] = value;
+
+  // Value is supported as it is. Note that we just make sure it is not an empty
+  // string. Browsers will sometimes rewrite values, but still accept them. They
+  // will set the value to an empty string if not supported.
+  // E.g. for border, "solid 1px black" becomes "1px solid black"
+  //      but "foobar" becomes "", since it is not supported.
+  if (domStyle[property]) {
+    prefixedValueCache[cacheKey] = value;
+    return value;
+  }
+
+  // Test value with vendor prefix.
+  value = cssVendorPrefix + value;
+  domStyle[property] = value;
+
+  // Value is supported with vendor prefix.
+  if (domStyle[property]) {
+    prefixedValueCache[cacheKey] = value;
+    return value;
+  }
+
+  return prefixedValueCache[cacheKey] = false;
+};
+
+// Returns a new style object with vendor prefixes added to property names
+// and values.
+/*eslint-disable no-console */
+var prefix = function (style, mode /* 'css' or 'js' */) {
+  mode = mode || 'js';
+  var newStyle = {};
+  Object.keys(style).forEach(function (property) {
+    var value = style[property];
+
+    var newProperty = _getPrefixedProperty(property);
+    if (newProperty === false) {
+      // Ignore unsupported properties
+      console.warn('Unsupported CSS property ' + property);
+      return;
+    }
+
+    var newValue = _getPrefixedValue(newProperty.js, value);
+    if (newValue === false) {
+      // Ignore unsupported values
+      console.warn(
+        'Unsupported CSS value ' + value + ' for property ' + property
+      );
+    }
+
+    newStyle[newProperty[mode]] = newValue;
+  });
+  return newStyle;
+};
+/*eslint-enable no-console */
+
+module.exports = prefix;

modules/resolve-styles.js

@@ -2,6 +2,7 @@
 
 var MouseUpListener = require('./mouse-up-listener');
 var getState = require('./get-state');
+var prefix = require('./prefix');
 
 var React = require('react/addons');
 var clone = require('lodash/lang/clone');
@@ -136,7 +137,8 @@ var resolveStyles = function (component, renderedElement, existingKeyMap) {
     !Object.keys(style).some(_isSpecialKey)
   ) {
     if (style) {
-      newProps.style = style;
+      // Still perform vendor prefixing, though.
+      newProps.style = prefix(style);
       return React.cloneElement(renderedElement, newProps, newChildren);
     } else if (newChildren) {
       return React.cloneElement(renderedElement, {}, newChildren);
@@ -229,7 +231,7 @@ var resolveStyles = function (component, renderedElement, existingKeyMap) {
     );
   }
 
-  newProps.style = newStyle;
+  newProps.style = prefix(newStyle);
 
   return React.cloneElement(renderedElement, newProps, newChildren);
 };