From 6df6958dea212ffae72f1db7a286ed386a1e4e8c Mon Sep 17 00:00:00 2001
From: AryanRG <aryanrganjoo@gmail.com>
Date: Fri, 16 Oct 2026 23:37:39 +0530
Subject: [PATCH] fix: validate MUVERA dimensions

---
 fastembed/postprocess/muvera.py | 11 +++++++++--
 tests/test_postprocess.py       | 14 ++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/fastembed/postprocess/muvera.py b/fastembed/postprocess/muvera.py
index 31d3ad36..77833262 100644
--- a/fastembed/postprocess/muvera.py
+++ b/fastembed/postprocess/muvera.py
@@ -126,8 +126,14 @@ def __init__(
                                          reproducible results. Defaults to 42.
 
         Raises:
-            ValueError: If dim_proj > dim (cannot project to higher dimensionality)
+            ValueError: If dim, dim_proj, or r_reps are not positive, or if dim_proj > dim
         """
+        if dim <= 0:
+            raise ValueError(f"dim must be positive, got {dim}")
+        if dim_proj <= 0:
+            raise ValueError(f"dim_proj must be positive, got {dim_proj}")
+        if r_reps <= 0:
+            raise ValueError(f"r_reps must be positive, got {r_reps}")
         if dim_proj > dim:
             raise ValueError(
                 f"Cannot project to a higher dimensionality (dim_proj={dim_proj} > dim={dim})"
@@ -186,7 +192,8 @@ def from_multivector_model(
             Muvera: A configured MUVERA instance ready to process embeddings from the given model.
 
         Raises:
-            ValueError: If dim_proj > model.embedding_size (cannot project to higher dimensionality)
+            ValueError: If the model dimension, dim_proj, or r_reps are not positive, or if
+                        dim_proj > model.embedding_size
 
         Example:
             >>> from fastembed import LateInteractionTextEmbedding
diff --git a/tests/test_postprocess.py b/tests/test_postprocess.py
index 92f485f1..53c0f056 100644
--- a/tests/test_postprocess.py
+++ b/tests/test_postprocess.py
@@ -18,6 +18,20 @@
 R_REPS = 20
 
 
+@pytest.mark.parametrize(
+    ("kwargs", "message"),
+    [
+        ({"dim": 0, "dim_proj": 0}, "dim must be positive"),
+        ({"dim": 4, "dim_proj": 0}, "dim_proj must be positive"),
+        ({"dim": 4, "dim_proj": 2, "r_reps": 0}, "r_reps must be positive"),
+    ],
+)
+def test_muvera_rejects_non_positive_sizes(kwargs: dict[str, int], message: str) -> None:
+    """Configurations that cannot produce an embedding must fail during construction."""
+    with pytest.raises(ValueError, match=message):
+        Muvera(**kwargs)
+
+
 def test_single_input():
     model = LateInteractionTextEmbedding("colbert-ir/colbertv2.0", lazy_load=True)
     random_generator = np.random.default_rng(42)