Added polyfill for Object.is, fixes #77

immerjs · Jan 19, 2018 · cf0b1e1 · cf0b1e1
1 parent 737e556
commit cf0b1e1
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Showing 3 changed files with 15 additions and 4 deletions.
diff --git a/src/common.js b/src/common.js
@@ -118,3 +118,12 @@ export function verifyReturnValue(value) {
             `Immer callback expects no return value. However ${typeof value} was returned`
         )
 }
+
+export function is(x, y) {
+    // From: https://github.com/facebook/fbjs/blob/c69904a511b900266935168223063dd8772dfc40/packages/fbjs/src/core/shallowEqual.js
+    if (x === y) {
+        return x !== 0 || 1 / x === 1 / y
+    } else {
+        return x !== x && y !== y
+    }
+}
diff --git a/src/es5.js b/src/es5.js
@@ -2,6 +2,7 @@
 // @ts-check
 
 import {
+    is,
     isProxyable,
     isProxy,
     freeze,
@@ -46,7 +47,7 @@ function get(state, prop) {
 function set(state, prop, value) {
     assertUnfinished(state)
     if (!state.modified) {
-        if (Object.is(source(state)[prop], value)) return
+        if (is(source(state)[prop], value)) return
         markChanged(state)
         prepareCopy(state)
     }
@@ -189,7 +190,7 @@ export function produceEs5(baseState, producer) {
 
 function shallowEqual(objA, objB) {
     //From: https://github.com/facebook/fbjs/blob/c69904a511b900266935168223063dd8772dfc40/packages/fbjs/src/core/shallowEqual.js
-    if (Object.is(objA, objB)) return true
+    if (is(objA, objB)) return true
     if (
         typeof objA !== "object" ||
         objA === null ||
@@ -204,7 +205,7 @@ function shallowEqual(objA, objB) {
     for (let i = 0; i < keysA.length; i++) {
         if (
             !hasOwnProperty.call(objB, keysA[i]) ||
-            !Object.is(objA[keysA[i]], objB[keysA[i]])
+            !is(objA[keysA[i]], objB[keysA[i]])
         ) {
             return false
         }

diff --git a/src/proxy.js b/src/proxy.js
@@ -2,6 +2,7 @@
 // @ts-check
 
 import {
+    is,
     isProxyable,
     isProxy,
     freeze,
@@ -73,7 +74,7 @@ function get(state, prop) {
 function set(state, prop, value) {
     if (!state.modified) {
         if (
-            (prop in state.base && Object.is(state.base[prop], value)) ||
+            (prop in state.base && is(state.base[prop], value)) ||
             (prop in state.proxies && state.proxies[prop] === value)
         )
             return true