From a15794f40f7acf6e0648d1ff35328e3e4ca4239d Mon Sep 17 00:00:00 2001
From: Jakub Strojewski <jakub.strojewski@gmail.com>
Date: Tue, 19 Nov 2024 14:50:33 +0000
Subject: [PATCH] Make null param error more informative (#809)

---
 .../core/src/main/scala/doobie/util/put.scala | 24 ++++++++++++++-----
 .../test/scala/doobie/util/WriteSuite.scala   |  2 +-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/modules/core/src/main/scala/doobie/util/put.scala b/modules/core/src/main/scala/doobie/util/put.scala
index 752f6df16..74e2881af 100644
--- a/modules/core/src/main/scala/doobie/util/put.scala
+++ b/modules/core/src/main/scala/doobie/util/put.scala
@@ -56,25 +56,37 @@ sealed abstract class Put[A](
     ) {}
 
   def unsafeSetNonNullable(ps: PreparedStatement, n: Int, a: A): Unit =
-    if (a == null) sys.error(s"Expected non-nullable param at $n. Use Option to describe nullable values.")
-    else put.fi.apply(ps, n, (put.k(a)))
+    unsafeSetWhatShouldNotBeNull(ps, n, a, expectedNonNullableParam)
 
   def unsafeSetNullable(ps: PreparedStatement, n: Int, oa: Option[A]): Unit =
     oa match {
-      case Some(a) => unsafeSetNonNullable(ps, n, a)
+      case Some(a) => unsafeSetWhatShouldNotBeNull(ps, n, a, expectedOptionalParam)
       case None    => unsafeSetNull(ps, n)
     }
 
+  private def unsafeSetWhatShouldNotBeNull(ps: PreparedStatement, n: Int, a: A, message: Int => String): Unit =
+    if (a == null) sys.error(message(n))
+    else put.fi.apply(ps, n, (put.k(a)))
+
   def unsafeUpdateNonNullable(rs: ResultSet, n: Int, a: A): Unit =
-    if (a == null) sys.error(s"Expected non-nullable param at $n. Use Option to describe nullable values.")
-    else update.fi.apply(rs, n, (update.k(a)))
+    unsafeUpdateWhatShouldNotBeNull(rs, n, a, expectedNonNullableParam)
 
   def unsafeUpdateNullable(rs: ResultSet, n: Int, oa: Option[A]): Unit =
     oa match {
-      case Some(a) => unsafeUpdateNonNullable(rs, n, a)
+      case Some(a) => unsafeUpdateWhatShouldNotBeNull(rs, n, a, expectedOptionalParam)
       case None    => rs.updateNull(n)
     }
 
+  private def unsafeUpdateWhatShouldNotBeNull(rs: ResultSet, n: Int, a: A, message: Int => String): Unit =
+    if (a == null) sys.error(message(n))
+    else update.fi.apply(rs, n, (update.k(a)))
+
+  private def expectedNonNullableParam(n: Int) =
+    s"Expected non-nullable param at $n. Use Option to describe nullable values."
+
+  private def expectedOptionalParam(n: Int) =
+    s"Expected optional param at $n but got Some(null)."
+
   override def toString(): String = {
     s"Put(typeStack=${typeStack.mkString_(",")}, jdbcTargets=${jdbcTargets.mkString_(
         ",")}, vendorTypeNames=${vendorTypeNames.mkString_(",")})"
diff --git a/modules/core/src/test/scala/doobie/util/WriteSuite.scala b/modules/core/src/test/scala/doobie/util/WriteSuite.scala
index 33f756af6..42a05c2df 100644
--- a/modules/core/src/test/scala/doobie/util/WriteSuite.scala
+++ b/modules/core/src/test/scala/doobie/util/WriteSuite.scala
@@ -123,7 +123,7 @@ class WriteSuite extends munit.FunSuite with WriteSuitePlatform {
   }
 
   test("Write should yield correct error when Some(null) inserted") {
-    interceptMessage[RuntimeException]("Expected non-nullable param at 2. Use Option to describe nullable values.") {
+    interceptMessage[RuntimeException]("Expected optional param at 2 but got Some(null).") {
       testNullPut(("a", Some(null)))
     }
   }