Only warn once for deprecations

Author: taion

modules/routerWarning.js

@@ -1,6 +1,21 @@
 import warning from 'warning'
 
+let warned = {}
+
 export default function routerWarning(falseToWarn, message, ...args) {
+  // Only issue deprecation warnings once.
+  if (message.indexOf('deprecated') !== -1) {
+    if (warned[message]) {
+      return
+    }
+
+    warned[message] = true
+  }
+
   message = `[react-router] ${message}`
   warning(falseToWarn, message, ...args)
 }
+
+export function _resetWarned() {
+  warned = {}
+}

tests.webpack.js

@@ -3,6 +3,8 @@
 
 import expect from 'expect'
 
+import { _resetWarned } from './modules/routerWarning'
+
 beforeEach(() => {
   expect.spyOn(console, 'error').andCall(msg => {
     for (const about of console.error.expected) {
@@ -27,6 +29,7 @@ afterEach(() => {
   })
 
   console.error.restore()
+  _resetWarned()
 })
 
 const context = require.context('./modules', true, /-test\.js$/)