Fix failed tests.

Add browsers for features which depends on browserslist.

src/__tests__/fixtures/features/autoprefixer.browsers

@@ -0,0 +1 @@
+Safari 6

src/__tests__/fixtures/features/color-hex-alpha.browsers

@@ -0,0 +1 @@
+Safari 9

src/__tests__/fixtures/features/color-rgba.browsers

@@ -0,0 +1 @@
+IE 8

src/__tests__/fixtures/features/custom-properties.browsers

@@ -0,0 +1 @@
+Safari 9

src/__tests__/fixtures/features/filter.browsers

@@ -0,0 +1 @@
+IE 11

src/__tests__/fixtures/features/initial.browsers

@@ -0,0 +1 @@
+Safari 9

src/__tests__/fixtures/features/overflow-wrap.browsers

@@ -0,0 +1 @@
+IE 11

src/__tests__/fixtures/features/pseudo-class-matches.browsers

@@ -0,0 +1 @@
+Safari 8

src/__tests__/fixtures/features/pseudo-class-not.browsers

@@ -0,0 +1 @@
+Safari 8

src/__tests__/fixtures/features/pseudo-elements.browsers

@@ -0,0 +1 @@
+IE 8

src/__tests__/fixtures/features/rem.browsers

@@ -0,0 +1 @@
+IE 8

src/__tests__/index.js

@@ -15,7 +15,7 @@ tape("postcss-cssnext is a postcss plugin", (t) => {
 tape("cssnext regression test", (t) => {
   const input = utils.readFixture("regression")
   const expected = utils.readFixture("regression.expected")
-  const actual = postcssnext().process(input).css.trim()
+  const actual = postcssnext({ browsers: "IE 6" }).process(input).css.trim()
 
   utils.write(utils.fixturePath("regression.actual"), actual)
 

src/__tests__/option.features.js

@@ -21,6 +21,12 @@ const testFeature = function(
 ) {
   const options = { features: { } }
 
+  const browsers = utils.readFixtureBrowsers(join("features", slug))
+
+  if (browsers) {
+    options.browsers = browsers
+  }
+
   // disable all features
   Object.keys(features).forEach(function(key) {
     options.features[key] = false

src/__tests__/utils/index.js

@@ -32,12 +32,22 @@ export default {
   },
 
   /**
-   * read a fixture
+   * read a fixture browsers
    * @param {String} name
-   * @param {String} ext (optional extension, default to ".css")
-   * @return the fixture content
+   * @return the fixture browsers string
+   */
+  readFixtureBrowsers(name) {
+    const filePath = this.fixturePath(name, ".browsers")
+    const exists = fs.existsSync(filePath)
+    return exists && fs.readFileSync(filePath, "utf8").split("\n")[0]
+  },
+
+  /**
+   * write a result
+   * @param {String} name
+   * @param {String} content
    */
   write(name, content) {
-    return fs.writeFileSync(name, content)
+    fs.writeFileSync(name, content)
   },
 }