From 0192bb60112c19a26866115d059a6576e76653c7 Mon Sep 17 00:00:00 2001
From: Teo Camarasu <teofilcamarasu@gmail.com>
Date: Mon, 21 Sep 2026 15:37:54 +0100
Subject: [PATCH] Fix Char test failing from hitting NULL chars

---
 changelog.d/20260921_153711_teofilcamarasu.md | 3 +++
 rel8/tests/Main.hs                            | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/20260921_153711_teofilcamarasu.md

diff --git a/changelog.d/20260921_153711_teofilcamarasu.md b/changelog.d/20260921_153711_teofilcamarasu.md
new file mode 100644
index 00000000..41508184
--- /dev/null
+++ b/changelog.d/20260921_153711_teofilcamarasu.md
@@ -0,0 +1,3 @@
+### Fixed
+
+- Avoid generating NULL characters in the test suite as postgres doesn't accept these.
diff --git a/rel8/tests/Main.hs b/rel8/tests/Main.hs
index 88fc656f..463ae070 100644
--- a/rel8/tests/Main.hs
+++ b/rel8/tests/Main.hs
@@ -568,7 +568,7 @@ testDBType getTestDatabase = testGroup "DBType instances"
   [ dbTypeTest "Bool" Gen.bool
   , dbTypeTest "ByteString" $ Gen.bytes (Range.linear 0 128)
   , dbTypeTest "CalendarDiffTime" genCalendarDiffTime
-  , dbTypeTest "Char" Gen.unicode
+  , dbTypeTest "Char" genChar 
   , dbTypeTest "CI Lazy Text" $ mk . Data.Text.Lazy.fromStrict <$> genText
   , dbTypeTest "CI Text" $ mk <$> genText
   , dbTypeTest "Composite" genComposite
@@ -672,6 +672,11 @@ testDBType getTestDatabase = testGroup "DBType instances"
             Rel8.many . Rel8.many . Rel8.many . (Rel8.catListTable >=> Rel8.catListTable >=> Rel8.catListTable)
         diff res''' (==) [[[x, y]]]
 
+    genChar :: Gen Char
+    genChar =
+      -- Filter out NULL as that isn't accepted by Postgres
+      Gen.filter (/= '\0') Gen.unicode
+
     genScientific :: Gen Scientific
     genScientific = (/ 10) . fromIntegral @Int @Scientific <$> Gen.integral (Range.linear (-100) 100)