refactor(tests): add helper for invalid case

Author: LouisTsai-Csie

tests/osaka/eip7883_modexp_gas_increase/test_modexp_thresholds.py

@@ -43,64 +43,75 @@ def test_vectors_from_file(
     )
 
 
-@pytest.mark.parametrize(
-    "modexp_input,modexp_expected,call_succeeds",
-    [
+def create_modexp_input(
+    bsize: int, esize: int, msize: int, e_data: str = "", m_data: str = "", b_data: str = ""
+) -> bytes:
+    """
+    Create ModExp input data with specified sizes and data.
+
+    Args:
+        bsize: Base size in bytes
+        esize: Exponent size in bytes
+        msize: Modulus size in bytes
+        e_data: Exponent data (hex string, if not provided, will be padded with FF)
+        m_data: Modulus data (hex string, if not provided, will be padded with FF)
+        b_data: Base data (hex string, if not provided, will be padded with FF)
+
+    Returns:
+        ModExp input as bytes
+
+    """
+    e_padded = "FF" * esize if not e_data else e_data
+    m_padded = "FF" * msize if not m_data else m_data
+    b_padded = "FF" * bsize if not b_data else b_data
+
+    # Format sizes as 32-byte hex strings
+    bsize_hex = format(bsize, "032x")
+    esize_hex = format(esize, "032x")
+    msize_hex = format(msize, "032x")
+
+    # Concatenate all parts
+    input_hex = bsize_hex + esize_hex + msize_hex + e_padded + m_padded + b_padded
+    return bytes.fromhex(input_hex)
+
+
+def generate_invalid_inputs_cases():
+    """Generate test cases for invalid ModExp inputs."""
+    return [
         pytest.param(bytes(), bytes(), False, id="zero-length-calldata"),
         pytest.param(
-            bytes.fromhex(
-                format(10, "032x")  # Bsize
-                + format(11, "032x")  # Esize
-                + format(12, "032x")  # Msize
-                + "FF" * 9  # E
-                + "FF" * 11  # M
-                + "FF" * 12  # B
-            ),
+            create_modexp_input(10, 11, 12, b_data="FF" * 9),
             bytes(),
             False,
             id="b-too-short",
         ),
         pytest.param(
-            bytes.fromhex(
-                format(10, "032x")  # Bsize
-                + format(11, "032x")  # Esize
-                + format(12, "032x")  # Msize
-                + "FF" * 10  # E
-                + "FF" * 10  # M
-                + "FF" * 12  # B
-            ),
+            create_modexp_input(10, 11, 12, m_data="FF" * 10),
             bytes(),
             False,
             id="m-too-short",
         ),
         pytest.param(
-            bytes.fromhex(
-                format(10, "032x")  # Bsize
-                + format(11, "032x")  # Esize
-                + format(12, "032x")  # Msize
-                + "FF" * 10  # E
-                + "FF" * 11  # M
-                + "FF" * 11  # B
-            ),
+            create_modexp_input(10, 11, 12, e_data="FF" * 11),
             bytes(),
             False,
             id="e-too-short",
         ),
-        # Not sure if this is valid
         pytest.param(
-            bytes.fromhex(
-                format(0, "032x")  # Bsize
-                + format(0, "032x")  # Esize
-                + format(0, "032x")  # Msize
-            ),
+            create_modexp_input(0, 0, 0),
             bytes(),
             False,
             id="all-zeros",
         ),
-    ],
+    ]
+
+
+@pytest.mark.parametrize(
+    "modexp_input,modexp_expected,call_succeeds",
+    generate_invalid_inputs_cases(),
 )
 @EIPChecklist.Precompile.Test.Inputs.AllZeros
-def test_modexp_invalid(
+def test_modexp_invalid_inputs(
     state_test: StateTestFiller,
     pre: Alloc,
     tx: Transaction,