save some bundle size

Author: oliviertassinari

packages/material-ui/src/utils/exactProp.js

@@ -7,6 +7,7 @@
 export const specialProperty = 'exact-prop: \u200b';
 
 function exactProp(propTypes: Object) {
+  /* istanbul ignore if */
   if (process.env.NODE_ENV === 'production') {
     return propTypes;
   }

packages/material-ui/src/utils/requirePropFactory.js

@@ -1,6 +1,11 @@
 // @flow weak
 
 function requirePropFactory(componentNameInError: string) {
+  /* istanbul ignore if */
+  if (process.env.NODE_ENV === 'production') {
+    return () => null;
+  }
+
   const requireProp = (requiredProp: string) => (
     props: Object,
     propName: string,

packages/material-ui/src/utils/unsupportedProp.js

@@ -7,6 +7,7 @@ function unsupportedProp(
   location?: string,
   propFullName?: string,
 ) {
+  /* istanbul ignore if */
   if (process.env.NODE_ENV === 'production') {
     return null;
   }