fix(probability): avoid bounded integer string limits

Author: morluto

src/jacobian/contracts/probability.py

@@ -8,7 +8,7 @@
 
 from pydantic import Field, StrictInt, model_validator
 
-from jacobian.canonical import canonicalize_json
+from jacobian.canonical import canonicalize_json, format_canonical_integer
 from jacobian.contracts.exact import CanonicalInteger, CanonicalRational
 from jacobian.contracts.graph_isomorphism import SimpleUndirectedGraph
 from jacobian.contracts.results import ContractModel
@@ -36,8 +36,8 @@ def _require_bounded_fraction(
     label: str,
 ) -> None:
     if (
-        len(str(abs(value.numerator))) > max_digits
-        or len(str(value.denominator)) > max_digits
+        len(format_canonical_integer(abs(value.numerator))) > max_digits
+        or len(format_canonical_integer(value.denominator)) > max_digits
     ):
         raise ValueError(f"{label} exceeds the {max_digits}-digit bound")
 
@@ -324,13 +324,25 @@ def require_bounded_fully_weighted_graph(self) -> Self:
         )
         probability_numerator_digits = sum(
             max(
-                len(str(item.open_probability.as_fraction().numerator)),
-                len(str((1 - item.open_probability.as_fraction()).numerator)),
+                len(
+                    format_canonical_integer(
+                        item.open_probability.as_fraction().numerator
+                    )
+                ),
+                len(
+                    format_canonical_integer(
+                        (1 - item.open_probability.as_fraction()).numerator
+                    )
+                ),
             )
             for item in self.edge_probabilities
         )
         probability_denominator_digits = sum(
-            len(str(item.open_probability.as_fraction().denominator))
+            len(
+                format_canonical_integer(
+                    item.open_probability.as_fraction().denominator
+                )
+            )
             for item in self.edge_probabilities
         )
         maximum_state = {

tests/unit/contracts/test_probability_contracts.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+import sys
+
+import pytest
+from pydantic import ValidationError
+
+from jacobian.contracts.probability import GraphReliabilityEdgeProbability
+
+
+@pytest.mark.parametrize(
+    ("num", "den"),
+    (
+        ("1" * (sys.int_info.default_max_str_digits + 1), "1"),
+        ("1", "1" * (sys.int_info.default_max_str_digits + 1)),
+    ),
+    ids=("numerator", "denominator"),
+)
+def test_large_probability_reports_the_contract_digit_bound(
+    num: str,
+    den: str,
+) -> None:
+    previous_limit = sys.get_int_max_str_digits()
+    sys.set_int_max_str_digits(sys.int_info.default_max_str_digits)
+    try:
+        with pytest.raises(
+            ValidationError,
+            match="graph reliability edge probability exceeds the 128-digit bound",
+        ):
+            GraphReliabilityEdgeProbability.model_validate(
+                {
+                    "edge": ["a", "b"],
+                    "open_probability": {
+                        "num": num,
+                        "den": den,
+                    },
+                }
+            )
+    finally:
+        sys.set_int_max_str_digits(previous_limit)