From 7a353f7776ad29ad5dce1953c61f841f7c3e6427 Mon Sep 17 00:00:00 2001
From: Nick Johnson <24689722+ntjohnson1@users.noreply.github.com>
Date: Fri, 14 Nov 2025 09:56:51 -0500
Subject: [PATCH] Add __radd__ for sptensor

---
 pyttb/sptensor.py      | 23 +++++++++++++++++++++++
 tests/test_sptensor.py |  8 ++++++++
 2 files changed, 31 insertions(+)

diff --git a/pyttb/sptensor.py b/pyttb/sptensor.py
index d1c7574e..3602c23b 100644
--- a/pyttb/sptensor.py
+++ b/pyttb/sptensor.py
@@ -2901,6 +2901,29 @@ def __add__(self, other):
         # Otherwise return negated sub
         return self.__sub__(-other)
 
+    def __radd__(self, other):
+        """
+        Right binary addition operator (+).
+
+        Parameters
+        ----------
+        other:
+            Object to add to the sparse tensor.
+
+        Examples
+        --------
+        Add a scalar value, returning a dense tensor:
+
+        >>> S = ttb.sptensor(shape=(2, 2))
+        >>> S[1, 1] = 1.0
+        >>> 1 + S
+        tensor of shape (2, 2) with order F
+        data[:, :] =
+        [[1. 1.]
+         [1. 2.]]
+        """
+        return self.__add__(other)
+
     def __pos__(self):
         """
         Unary plus operator (+).
diff --git a/tests/test_sptensor.py b/tests/test_sptensor.py
index 3d7eeea7..35d6493e 100644
--- a/tests/test_sptensor.py
+++ b/tests/test_sptensor.py
@@ -910,6 +910,14 @@ def test_sptensor__add__(sample_sptensor):
     assert np.array_equal(subSptensor.data, sptensorInstance.to_tensor().data)
 
 
+def test_sptensor__radd__(sample_sptensor):
+    (data, sptensorInstance) = sample_sptensor
+
+    # scalar + Sptensor
+    subSptensor = 0 + sptensorInstance
+    assert np.array_equal(subSptensor.data, sptensorInstance.to_tensor().data)
+
+
 def test_sptensor_isequal(sample_sptensor):
     (data, sptensorInstance) = sample_sptensor