From 0613ef10bdf29612d3cb64080f48c0969a164eb5 Mon Sep 17 00:00:00 2001
From: Phillip Cloud <417981+cpcloud@users.noreply.github.com>
Date: Thu, 22 Aug 2024 16:50:08 -0400
Subject: [PATCH] feat(api): make the `null` function deferrable

---
 ibis/common/tests/test_deferred.py | 10 ++++++++++
 ibis/expr/types/generic.py         |  1 +
 2 files changed, 11 insertions(+)

diff --git a/ibis/common/tests/test_deferred.py b/ibis/common/tests/test_deferred.py
index 616eebb47097..56bc1efb4a45 100644
--- a/ibis/common/tests/test_deferred.py
+++ b/ibis/common/tests/test_deferred.py
@@ -6,6 +6,7 @@
 import pytest
 from pytest import param
 
+import ibis
 from ibis.common.bases import Slotted
 from ibis.common.collections import FrozenDict
 from ibis.common.deferred import (
@@ -297,6 +298,9 @@ def __init__(self, name, dtype):
     def __deferred_repr__(self):
         return f"<column[{self.dtype}]>"
 
+    def type(self):
+        return self.dtype
+
 
 class UnaryMock(ValueMock):
     __slots__ = ("name", "arg")
@@ -602,3 +606,9 @@ def test_deferred_namespace(table):
 def test_custom_deferred_repr(table):
     expr = _.x + table.a
     assert repr(expr) == "(_.x + <column[int]>)"
+
+
+def test_null_deferrable(table):
+    result = ibis.null(_.a.type()).resolve(table).op()
+    expected = ibis.null(table.a.type()).op()
+    assert result == expected
diff --git a/ibis/expr/types/generic.py b/ibis/expr/types/generic.py
index f607ae9385d3..325950ebf72f 100644
--- a/ibis/expr/types/generic.py
+++ b/ibis/expr/types/generic.py
@@ -2399,6 +2399,7 @@ class NullColumn(Column, NullValue):
 
 
 @public
+@deferrable
 def null(type: dt.DataType | str | None = None) -> Value:
     """Create a NULL scalar.