Group features by browser support

Author: devongovett

build-prefixes.js

@@ -15,7 +15,7 @@ const BROWSER_MAPPING = {
   op_mini: null,
 };
 
-let p = {};
+let p = new Map();
 for (let prop in prefixes) {
   let browserMap = {};
   for (let b of prefixes[prop].browsers) {
@@ -43,17 +43,31 @@ for (let prop in prefixes) {
       }
     }
   }
-  p[prop] = browserMap;
+  // p[prop] = browserMap;
+  let s = JSON.stringify(browserMap);
+  let found = false;
+  for (let [key, val] of p) {
+    if (JSON.stringify(val) === s) {
+      key.push(prop);
+      found = true;
+      break;
+    }
+  }
+  if (!found) {
+    p.set([prop], browserMap);
+  }
 }
 
+console.log(p)
+
 let prefixMapping = {
   webkit: 'WebKit',
   moz: 'Moz',
   ms: 'Ms',
   o: 'O'
 };
 
-let enumify = (f) => f.replace(/^@/, 'At').replace(/^::/, 'PseudoElement').replace(/^:/, 'PseudoClass').replace(/(^|-)([a-z])/g, (_, a, x) => x.toUpperCase())
+let enumify = (f) => f.replace(/^@([a-z])/, (_, x) => 'At' + x.toUpperCase()).replace(/^::([a-z])/, (_, x) => 'PseudoElement' + x.toUpperCase()).replace(/^:([a-z])/, (_, x) => 'PseudoClass' + x.toUpperCase()).replace(/(^|-)([a-z])/g, (_, a, x) => x.toUpperCase())
 
 let s = `// This file is autogenerated by build-prefixes.js. DO NOT EDIT!
 
@@ -66,15 +80,15 @@ pub struct Browsers {
 }
 
 pub enum Feature {
-  ${Object.keys(p).map(enumify).sort().join(',\n  ')}
+  ${[...p.keys()].flat().map(enumify).sort().join(',\n  ')}
 }
 
 impl Feature {
   pub fn prefixes_for(&self, browsers: Browsers) -> VendorPrefix {
     let mut prefixes = VendorPrefix::None;
     match self {
-      ${Object.entries(p).map(([name, versions]) => {
-        return `Feature::${enumify(name)} => {
+      ${[...p].map(([features, versions]) => {
+        return `${features.map(name => `Feature::${enumify(name)}`).join(' |\n      ')} => {
         ${Object.entries(versions).map(([name, prefixes]) => {
           return `if let Some(version) = browsers.${name} {
           ${Object.entries(prefixes).map(([prefix, [min, max]]) => {