From 4a6f2ec44a0cee0fde7e31105a3da9ef91e27f69 Mon Sep 17 00:00:00 2001
From: Theo Yaung <theoy@fb.com>
Date: Thu, 8 Dec 2016 13:31:52 -0800
Subject: [PATCH] Fail-Fast on Redundant Callback Invokes

Reviewed By: javache

Differential Revision: D4295268

fbshipit-source-id: 1258ffbc02bcf7d7199348c7df8fcd744bb9963f
---
 React/Base/RCTModuleMethod.m | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/React/Base/RCTModuleMethod.m b/React/Base/RCTModuleMethod.m
index 3b72f9f066565a..5f5c9e2dc2bb8a 100644
--- a/React/Base/RCTModuleMethod.m
+++ b/React/Base/RCTModuleMethod.m
@@ -102,6 +102,17 @@ static RCTNullability RCTParseNullabilityPostfix(const char **input)
   return RCTNullabilityUnspecified;
 }
 
+// returns YES if execution is safe to proceed (enqueue callback invocation), NO if callback has already been invoked
+static BOOL RCTCheckCallbackMultipleInvocations(BOOL *didInvoke) {
+    if (*didInvoke) {
+        RCTFatal(RCTErrorWithMessage(@"Illegal callback invocation from native module. This callback type only permits a single invocation from native code."));
+        return NO;
+    } else {
+        *didInvoke = YES;
+        return YES;
+    }
+}
+
 SEL RCTParseMethodSignature(NSString *, NSArray<RCTMethodArgument *> **);
 SEL RCTParseMethodSignature(NSString *methodSignature, NSArray<RCTMethodArgument *> **arguments)
 {
@@ -205,8 +216,11 @@ - (void)processMethodSignature
         return NO;
       }
 
+      __block BOOL didInvoke = NO;
       RCT_BLOCK_ARGUMENT(^(NSArray *args) {
-        [bridge enqueueCallback:json args:args];
+        if (RCTCheckCallbackMultipleInvocations(&didInvoke)) {
+          [bridge enqueueCallback:json args:args];
+        }
       });
     )
   };
@@ -302,8 +316,11 @@ - (void)processMethodSignature
           return NO;
         }
 
+        __block BOOL didInvoke = NO;
         RCT_BLOCK_ARGUMENT(^(NSError *error) {
-          [bridge enqueueCallback:json args:@[RCTJSErrorFromNSError(error)]];
+          if (RCTCheckCallbackMultipleInvocations(&didInvoke)) {
+            [bridge enqueueCallback:json args:@[RCTJSErrorFromNSError(error)]];
+          }
         });
       )
     } else if ([typeName isEqualToString:@"RCTPromiseResolveBlock"]) {
@@ -316,8 +333,11 @@ - (void)processMethodSignature
           return NO;
         }
 
+        __block BOOL didInvoke = NO;
         RCT_BLOCK_ARGUMENT(^(id result) {
-          [bridge enqueueCallback:json args:result ? @[result] : @[]];
+          if (RCTCheckCallbackMultipleInvocations(&didInvoke)) {
+            [bridge enqueueCallback:json args:result ? @[result] : @[]];
+          }
         });
       )
     } else if ([typeName isEqualToString:@"RCTPromiseRejectBlock"]) {
@@ -330,9 +350,12 @@ - (void)processMethodSignature
           return NO;
         }
 
+        __block BOOL didInvoke = NO;
         RCT_BLOCK_ARGUMENT(^(NSString *code, NSString *message, NSError *error) {
-          NSDictionary *errorJSON = RCTJSErrorFromCodeMessageAndNSError(code, message, error);
-          [bridge enqueueCallback:json args:@[errorJSON]];
+          if (RCTCheckCallbackMultipleInvocations(&didInvoke)) {
+            NSDictionary *errorJSON = RCTJSErrorFromCodeMessageAndNSError(code, message, error);
+            [bridge enqueueCallback:json args:@[errorJSON]];
+          }
         });
       )
     } else {