From 8ba33e88cfbbdcf142fa3793d03757f10c592d51 Mon Sep 17 00:00:00 2001
From: Orion Kindel <orionkindel@gmail.com>
Date: Fri, 3 May 2024 14:05:51 -0500
Subject: [PATCH] fix: maybe this has already been emitted

---
 src/Node.Stream.CSV.Parse.purs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/Node.Stream.CSV.Parse.purs b/src/Node.Stream.CSV.Parse.purs
index 1521a82..f568b2a 100644
--- a/src/Node.Stream.CSV.Parse.purs
+++ b/src/Node.Stream.CSV.Parse.purs
@@ -17,7 +17,7 @@ import Data.Either (Either(..))
 import Data.Filterable (filter)
 import Data.Map (Map)
 import Data.Map as Map
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..), isNothing)
 import Data.Newtype (wrap)
 import Data.Nullable (Nullable)
 import Data.Nullable as Nullable
@@ -117,7 +117,10 @@ foreach
 foreach stream cb = do
   UnliftAff unlift <- askUnliftAff
 
-  liftAff $ makeAff \res -> pure mempty <* flip (Event.once columnsH) stream $ const do
+  alreadyHaveCols <- liftEffect $ getOrInitColumnsMap stream
+  when (isNothing alreadyHaveCols)
+    $ liftAff
+    $ makeAff \res -> pure mempty <* flip (Event.once columnsH) stream $ const do
     void $ getOrInitColumnsMap stream
     res $ Right unit