test(kzg10, field): Add comprehensive unit tests for KZG10Commitment

Implement tests for setup, commit, prove_eval, verify_eval,
prove_degree_bound, verify_degree_bound, prove_eval_and_degree,
and verify_eval_and_degree methods. Include edge cases and error handling.

src/field.py

@@ -138,4 +138,5 @@ def magic_field(value):
     magic_field.zero = lambda : Fp.zero()
     magic_field.one = lambda : Fp.one()
     magic_field.primitive_element = lambda : Fp.primitive_element()
+    magic_field.random_element = lambda : Fp.random_element()
     return magic_field

src/kzg10.py

@@ -85,7 +85,9 @@ def commit(self, polynomial) -> Commitment:
 
         if isinstance(polynomial, list):
             polynomial = UniPolynomial(polynomial)
-        elif not isinstance(polynomial, type(Commitment.scalar)):    
+        elif isinstance(polynomial, UniPolynomial):
+            pass
+        else:
             raise TypeError("Invalid polynomial type")
 
         if polynomial.degree > self.max_degree:

tests/test_kzg10.py

@@ -0,0 +1,104 @@
+import unittest
+
+import sys
+
+sys.path.append('../src')
+sys.path.append('src')
+
+from kzg10 import KZG10Commitment, Commitment
+from group import DummyGroup
+from unipolynomial import UniPolynomial
+from sage.all import *
+from field import magic
+
+Fp = magic(GF(193))
+
+class TestKZG10Commitment(unittest.TestCase):
+    def setUp(self):
+        self.G1 = DummyGroup(Fp)
+        self.G2 = DummyGroup(Fp)
+        self.max_degree = 10
+        self.kzg = KZG10Commitment(self.G1, self.G2, self.max_degree)
+
+    def test_setup(self):
+        self.assertEqual(len(self.kzg.srs), self.max_degree + 1)
+        self.assertEqual(len(self.kzg.srs2), self.max_degree + 1)
+        self.assertIsNotNone(self.kzg.h)
+        self.assertIsNotNone(self.kzg.h_s)
+
+    def test_commit(self):
+        poly = UniPolynomial([1, 2, 3])  # 1 + 2x + 3x^2
+        commitment = self.kzg.commit(poly)
+        self.assertIsInstance(commitment, Commitment)
+        self.assertEqual(commitment.group, self.G1)
+
+    def test_commit_invalid_type(self):
+        with self.assertRaises(TypeError):
+            self.kzg.commit("invalid")
+
+    def test_commit_degree_too_high(self):
+        poly = UniPolynomial([1] * (self.max_degree + 2))
+        with self.assertRaises(ValueError):
+            self.kzg.commit(poly)
+
+    def test_division_by_linear_divisor(self):
+        coeffs = [1, 2, 1]  # x^2 + 2x + 1
+        d = 1
+        quotient, remainder = KZG10Commitment.division_by_linear_divisor(coeffs, d)
+        self.assertEqual(quotient, [3, 1])  # x + 3
+        self.assertEqual(remainder, 4)  # f(1) = 1^2 + 2*1 + 1 = 4
+
+    def test_prove_eval(self):
+        poly = [1, 2, 3]  # 1 + 2x + 3x^2
+        point = 2
+        value = 17  # f(2) = 1 + 2*2 + 3*2^2 = 17
+        proof = self.kzg.prove_eval(poly, point, value)
+        self.assertIsInstance(proof, Commitment)
+
+    def test_verify_eval(self):
+        poly = [1, 2, 3]  # 1 + 2x + 3x^2
+        point = 2
+        value = 17  # f(2) = 1 + 2*2 + 3*2^2 = 17
+        commitment = self.kzg.commit(poly)
+        proof = self.kzg.prove_eval(poly, point, value)
+        result = self.kzg.verify_eval(commitment, proof, point, value)
+        self.assertTrue(result)
+
+    def test_prove_degree_bound(self):
+        poly = [1, 2, 3, 0, 0]  # 1 + 2x + 3x^2
+        commitment = self.kzg.commit(poly)
+        degree_bound = 3
+        proof = self.kzg.prove_degree_bound(commitment, poly, degree_bound)
+        self.assertIsInstance(proof[0], Commitment)
+        self.assertIsInstance(proof[1], int)
+
+    def test_verify_degree_bound(self):
+        poly = [1, 2, 3, 0, 0]  # 1 + 2x + 3x^2
+        commitment = self.kzg.commit(poly)
+        degree_bound = 3
+        proof = self.kzg.prove_degree_bound(commitment, poly, degree_bound)
+        result = self.kzg.verify_degree_bound(commitment, proof, degree_bound)
+        self.assertTrue(result)
+
+    def test_prove_eval_and_degree(self):
+        poly = [1, 2, 3, 0, 0]  # 1 + 2x + 3x^2
+        commitment = self.kzg.commit(poly)
+        point = 2
+        value = 17  # f(2) = 1 + 2*2 + 3*2^2 = 17
+        degree_bound = 3
+        proof = self.kzg.prove_eval_and_degree(commitment, poly, point, value, degree_bound)
+        self.assertIsInstance(proof[0], Commitment)
+        self.assertIsInstance(proof[1], int)
+
+    def test_verify_eval_and_degree(self):
+        poly = [1, 2, 3, 0, 0]  # 1 + 2x + 3x^2
+        commitment = self.kzg.commit(poly)
+        point = 2
+        value = 17  # f(2) = 1 + 2*2 + 3*2^2 = 17
+        degree_bound = 3
+        proof = self.kzg.prove_eval_and_degree(commitment, poly, point, value, degree_bound)
+        result = self.kzg.verify_eval_and_degree(commitment, proof, point, value, degree_bound)
+        self.assertTrue(result)
+
+if __name__ == '__main__':
+    unittest.main()