Update to postcss v7 and postcss-preset-env (#7)

Author: goto-bus-stop

.gitignore

@@ -3,3 +3,4 @@ coverage/
 tmp/
 npm-debug.log*
 .DS_Store
+.nyc_output

.travis.yml

@@ -1,7 +1,8 @@
+language: node_js
 node_js:
 - "stable"
-- "4"
-sudo: false
-language: node_js
+- "12"
+- "10"
+- "8"
 script: "npm run test:cov"
 after_script: "npm i -g codecov.io && cat ./coverage/lcov.info | codecov"

fixtures/basic-out.css

@@ -1,4 +1,8 @@
-hello, world {
-  -webkit-transform: translate(0, 0);
-          transform: translate(0, 0);
+:root {
+  --mainColor: rgba(18,52,86,0.47059);
+}
+
+body {
+  color: rgba(18,52,86,0.47059);
+  color: var(--mainColor);
 }

fixtures/basic.css

@@ -1,3 +1,7 @@
-hello, world {
-  transform: translate(0, 0);
+:root {
+  --mainColor: #12345678;
+}
+
+body {
+  color: var(--mainColor);
 }

index.js

@@ -1,14 +1,8 @@
 const postcss = require('postcss')
-const cssnext = require('postcss-cssnext')
+const cssnext = require('postcss-preset-env')
 const imports = require('postcss-import')
 const xtend = require('xtend')
 
-// Patch CSSNext features map to ensure Node v4 support
-const features = require('postcss-cssnext/lib/features').default
-features.calc = function calc (options) {
-  return require('postcss-calc')(options)
-}
-
 module.exports = transform
 
 function transform (filename, source, options, done) {

package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "deps": "dependency-check . && dependency-check . --extra --no-dev",
     "test": "standard && npm run deps && NODE_ENV=test node test",
-    "test:cov": "standard && npm run deps && NODE_ENV=test istanbul cover test.js"
+    "test:cov": "standard && npm run deps && NODE_ENV=test nyc node test.js"
   },
   "repository": "stackcss/sheetify-cssnext",
   "keywords": [
@@ -22,17 +22,16 @@
   ],
   "license": "MIT",
   "dependencies": {
-    "postcss": "^6.0.17",
-    "postcss-calc": "6.0.1",
-    "postcss-cssnext": "^3.1.0",
-    "postcss-import": "^11.0.0",
+    "postcss": "^7.0.17",
+    "postcss-import": "^12.0.1",
+    "postcss-preset-env": "^6.7.0",
     "xtend": "^4.0.0"
   },
   "devDependencies": {
     "dependency-check": "^2.5.1",
-    "istanbul": "^0.4.1",
-    "standard": "^10.0.3",
-    "tape": "^4.2.1"
+    "nyc": "^14.1.1",
+    "standard": "^14.3.4",
+    "tape": "^5.0.1"
   },
   "engines": {
     "node": ">= 4"