Completely updated React, fixed #11, (hopefully)

goTorrentWebUI/node_modules/material-ui/styles/createBreakpoints.js.flow

@@ -1,16 +1,14 @@
-// @flow
-
-export type Breakpoint = 'xs' | 'sm' | 'md' | 'lg' | 'xl';
-
 // Sorted ASC by size. That's important.
 // It can't be configured as it's used statically for propTypes.
 export const keys = ['xs', 'sm', 'md', 'lg', 'xl'];
 
 // Keep in mind that @media is inclusive by the CSS specification.
-export default function createBreakpoints(breakpoints: Object) {
+export default function createBreakpoints(breakpoints) {
   const {
+    // The breakpoint **start** at this value.
+    // For instance with the first breakpoint xs: [xs, sm[.
     values = {
-      xs: 360,
+      xs: 0,
       sm: 600,
       md: 960,
       lg: 1280,
@@ -22,35 +20,37 @@ export default function createBreakpoints(breakpoints: Object) {
   } = breakpoints;
 
   function up(key) {
-    let value;
-    // min-width of xs starts at 0
-    if (key === 'xs') {
-      value = 0;
-    } else {
-      value = values[key] || key;
-    }
+    const value = typeof values[key] === 'number' ? values[key] : key;
     return `@media (min-width:${value}${unit})`;
   }
 
   function down(key) {
-    const value = values[key] || key;
+    const endIndex = keys.indexOf(key) + 1;
+    const upperbound = values[keys[endIndex]];
+
+    if (endIndex === keys.length) {
+      // xl down applies to all sizes
+      return up('xs');
+    }
+
+    const value = typeof upperbound === 'number' && endIndex > 0 ? upperbound : key;
     return `@media (max-width:${value - step / 100}${unit})`;
   }
 
   function between(start, end) {
-    const startIndex = keys.indexOf(start);
-    const endIndex = keys.indexOf(end);
+    const endIndex = keys.indexOf(end) + 1;
+
+    if (endIndex === keys.length) {
+      return up(start);
+    }
+
     return (
-      `@media (min-width:${values[keys[startIndex]]}${unit}) and ` +
-      `(max-width:${values[keys[endIndex + 1]] - step / 100}${unit})`
+      `@media (min-width:${values[start]}${unit}) and ` +
+      `(max-width:${values[keys[endIndex]] - step / 100}${unit})`
     );
   }
 
   function only(key) {
-    const keyIndex = keys.indexOf(key);
-    if (keyIndex === keys.length - 1) {
-      return up(key);
-    }
     return between(key, key);
   }