fix gundeck aws endpoint parsing (#2921)

Fix broken parser for "endpoint already exists" error message. 
It tried to consume the end twice. This could not work.

changelog.d/3-bug-fixes/aws-error-message-parser-bug

@@ -0,0 +1 @@
+The parser for the AWS/SNS error message to explain that an endpoint is already in use was incorrect. This lead to an "invalid token" error when registering push tokens for multiple user accounts (user ids) instead of updating the SNS endpoint with an additional user id.

services/gundeck/gundeck.cabal

@@ -414,6 +414,7 @@ test-suite gundeck-tests
     Json
     MockGundeck
     Native
+    ParseExistsError
     Paths_gundeck
     Push
     ThreadBudget

services/gundeck/src/Gundeck/Aws.hs

@@ -48,6 +48,9 @@ module Gundeck.Aws
 
     -- * Feedback
     listen,
+
+    -- * Exported for testing purposes
+    parseExistsError,
   )
 where
 
@@ -323,14 +326,6 @@ createEndpoint u tr arnEnv app token = do
   where
     readArn r = either (throwM . InvalidArn r) pure (fromText r)
     tokenLength = toInteger . Text.length . Push.tokenText
-    -- Thank you Amazon for not having granular error codes!
-    parseExistsError Nothing = Nothing
-    parseExistsError (Just s) = hush . flip parseOnly (toText s) $ do
-      _ <- string "Invalid parameter: Token Reason: Endpoint "
-      let endParser = string " already exists with the same Token, but different attributes."
-      a <- manyTill anyChar endParser >>= either fail pure . AWS.fromText . Text.pack
-      _ <- endParser
-      pure a
     isTokenError Nothing = False
     isTokenError (Just s) = isRight . flip parseOnly (toText s) $ do
       _ <- string "Invalid parameter: Token"
@@ -344,6 +339,14 @@ createEndpoint u tr arnEnv app token = do
           <|> string "iOS device tokens must be no more than 400 hexadecimal characters"
       pure ()
 
+-- Thank you Amazon for not having granular error codes!
+parseExistsError :: Maybe AWS.ErrorMessage -> Maybe EndpointArn
+parseExistsError Nothing = Nothing
+parseExistsError (Just s) = hush . flip parseOnly (toText s) $ do
+  _ <- string "Invalid parameter: Token Reason: Endpoint "
+  let endParser = string " already exists with the same Token, but different attributes."
+  manyTill anyChar endParser >>= either fail pure . AWS.fromText . Text.pack
+
 --------------------------------------------------------------------------------
 -- Publish
 

services/gundeck/test/unit/Main.hs

@@ -29,6 +29,7 @@ import qualified Json
 import qualified Native
 import Network.Wai.Utilities.Server (compile)
 import OpenSSL (withOpenSSL)
+import qualified ParseExistsError
 import qualified Push
 import Test.Tasty
 import Test.Tasty.HUnit
@@ -48,5 +49,6 @@ main =
         Json.tests,
         Native.tests,
         Push.tests,
-        ThreadBudget.tests
+        ThreadBudget.tests,
+        ParseExistsError.tests
       ]

services/gundeck/test/unit/ParseExistsError.hs

@@ -0,0 +1,39 @@
+module ParseExistsError where
+
+import Amazonka.Types
+import Gundeck.Aws
+import Gundeck.Aws.Arn
+import Gundeck.Types.Push.V2 (Transport (APNS))
+import Imports
+import Test.Tasty
+import Test.Tasty.HUnit
+
+tests :: TestTree
+tests =
+  testGroup
+    "parseExistsError"
+    [ testCase "parse error string from real world example" parseErrorTest,
+      testCase "parse errors" parseErrors
+    ]
+
+parseErrorTest :: Assertion
+parseErrorTest =
+  let e = Just $ ErrorMessage "Invalid parameter: Token Reason: Endpoint arn:aws:sns:eu-west-1:093205192929:endpoint/APNS/staging-com.wire.dev.ent/f90c8f08-a0a1-33bc-aa43-23c94770d936 already exists with the same Token, but different attributes."
+      expectedTopic = mkEndpointTopic (ArnEnv "staging") APNS "com.wire.dev.ent" (EndpointId "f90c8f08-a0a1-33bc-aa43-23c94770d936")
+      expected = mkSnsArn Ireland (Account "093205192929") expectedTopic
+   in parseExistsError e @?= Just expected
+
+parseErrors :: Assertion
+parseErrors = do
+  parseExistsError Nothing @?= Nothing
+  parseExistsError ((Just . ErrorMessage) "Invalid parameter: Token Reason: Endpoint") @?= Nothing
+  parseExistsError
+    ( (Just . ErrorMessage)
+        "Invalid parameter: Token Reason: Endpoint NO_ARN already exists with the same Token, but different attributes."
+    )
+    @?= Nothing
+  parseExistsError
+    ( (Just . ErrorMessage)
+        "Invalid parameter: Token Reason: Endpoint arn:aws:sns:eu-west-1:093205192929:endpoint/APNS/staging-com.wire.dev.ent/f90c8f08-a0a1-33bc-aa43-23c94770d936"
+    )
+    @?= Nothing