Merge branch 'v4-dev' into v4-navbars

1 files changed, 42 insertions, 0 deletions

diff --git a/grunt/postcss.js b/grunt/postcss.js
new file mode 100644
index 000000000..7e7eb4a7e
--- /dev/null
+++ b/grunt/postcss.js
@@ -0,0 +1,42 @@
+module.exports = {
+  use: [
+    'postcss-flexbugs-fixes',
+    'autoprefixer'
+  ],
+  map: {
+    inline: false,
+    annotation: true,
+    sourcesContent: true
+  },
+  autoprefixer: {
+    browsers: [
+      //
+      // Official browser support policy:
+      // https://v4-alpha.getbootstrap.com/getting-started/browsers-devices/#supported-browsers
+      //
+      'Chrome >= 35', // Exact version number here is kinda arbitrary
+      // Rather than using Autoprefixer's native "Firefox ESR" version specifier string,
+      // we deliberately hardcode the number. This is to avoid unwittingly severely breaking the previous ESR in the event that:
+      // (a) we happen to ship a new Bootstrap release soon after the release of a new ESR,
+      //     such that folks haven't yet had a reasonable amount of time to upgrade; and
+      // (b) the new ESR has unprefixed CSS properties/values whose absence would severely break webpages
+      //     (e.g. `box-sizing`, as opposed to `background: linear-gradient(...)`).
+      //     Since they've been unprefixed, Autoprefixer will stop prefixing them,
+      //     thus causing them to not work in the previous ESR (where the prefixes were required).
+      'Firefox >= 38', // Current Firefox Extended Support Release (ESR); https://www.mozilla.org/en-US/firefox/organizations/faq/
+      // Note: Edge versions in Autoprefixer & Can I Use refer to the EdgeHTML rendering engine version,
+      // NOT the Edge app version shown in Edge's "About" screen.
+      // For example, at the time of writing, Edge 20 on an up-to-date system uses EdgeHTML 12.
+      // See also https://github.com/Fyrd/caniuse/issues/1928
+      'Edge >= 12',
+      'Explorer >= 9',
+      // Out of leniency, we prefix these 1 version further back than the official policy.
+      'iOS >= 8',
+      'Safari >= 8',
+      // The following remain NOT officially supported, but we're lenient and include their prefixes to avoid severely breaking in them.
+      'Android 2.3',
+      'Android >= 4',
+      'Opera >= 12'
+    ]
+  }
+}