fix(rl): robust integer validation for utils.py (Fixes #953)

tunix/rl/rl_utils_test.py

@@ -0,0 +1,33 @@
+from tunix.rl import utils
+from absl.testing import absltest
+import numpy as np
+
+class UtilsTest(absltest.TestCase):
+
+    def test_is_positive_integer(self):
+        # 1. Standard Ints (Should Pass)
+        try:
+            utils.is_positive_integer(5, "test_var")
+            utils.is_positive_integer(1, "test_var")
+        except ValueError:
+            self.fail("is_positive_integer raised ValueError unexpectedly for int!")
+
+        # 2. Numpy Types (THIS IS THE BUG - It will fail now)
+        try:
+            utils.is_positive_integer(np.int64(5), "numpy_int")
+            utils.is_positive_integer(np.float32(5.0), "numpy_float")
+        except AttributeError:
+             # We catch AttributeError specifically because that's what we are fixing
+             self.fail("CRASH: AttributeError detected! The bug exists.")
+        except ValueError:
+            self.fail("is_positive_integer failed on Numpy types!")
+
+        # 3. Fail Cases (Should raise ValueError)
+        with self.assertRaisesRegex(ValueError, "positive integer"):
+            utils.is_positive_integer(5.5, "float_var")
+
+        with self.assertRaisesRegex(ValueError, "positive integer"):
+            utils.is_positive_integer(-5, "neg_var")
+
+if __name__ == '__main__':
+    absltest.main()

tunix/rl/utils.py

@@ -32,11 +32,27 @@
 NamedSharding = jax.sharding.NamedSharding
 
 
-def is_positive_integer(value: int | None, name: str):
-  """Checks if the value is positive."""
-  if value is not None and (not value.is_integer() or value <= 0):
-    raise ValueError(f"{name} must be a positive integer. Got: {value}")
+def is_integer_value(x):
+    """Checks if a value is effectively an integer (safe for all types)."""
+    # 1. Booleans are effectively integers (0/1) but we don't want them here.
+    if isinstance(x, bool):
+        return False
+
+    # 2. Native Ints and Numpy Ints (The fix for #903/#953)
+    if isinstance(x, (int, np.integer)):
+        return True
+
+    # 3. Floats that are actually integers (e.g. 5.0)
+    if isinstance(x, (float, np.floating)):
+        return x.is_integer()
+
+    return False
 
+def is_positive_integer(value, name: str):
+    """Checks if the value is positive and integer-like."""
+    # Use the new helper instead of calling .is_integer() directly
+    if value is not None and (not is_integer_value(value) or value <= 0):
+        raise ValueError(f"{name} must be a positive integer. Got: {value}")
 
 def check_divisibility(
     small_size,