fix(forge): fixed vm.parseJson not parsing powers of 10 correctly (#5155

)

evm/src/executor/inspector/cheatcodes/ext.rs

@@ -176,16 +176,38 @@ fn value_to_token(value: &Value) -> Result<Token> {
         }
         Value::Number(number) => {
             if let Some(f) = number.as_f64() {
+                // Check if the number has decimal digits because the EVM does not support floating
+                // point math
                 if f.fract() == 0.0 {
+                    // Use the string representation of the `serde_json` Number type instead of
+                    // calling f.to_string(), because some numbers are wrongly rounded up after
+                    // being convented to f64.
+                    // Example: 18446744073709551615 becomes 18446744073709552000 after parsing it
+                    // to f64.
                     let s = number.to_string();
+
+                    // Calling Number::to_string with powers of ten formats the number using
+                    // scientific notation and causes from_dec_str to fail. Using format! with f64
+                    // keeps the full number representation.
+                    // Example: 100000000000000000000 becomes 1e20 when Number::to_string is
+                    // used.
+                    let fallback_s = format!("{f}");
+
                     if let Ok(n) = U256::from_dec_str(&s) {
                         return Ok(Token::Uint(n))
                     }
                     if let Ok(n) = I256::from_dec_str(&s) {
                         return Ok(Token::Int(n.into_raw()))
                     }
+                    if let Ok(n) = U256::from_dec_str(&fallback_s) {
+                        return Ok(Token::Uint(n))
+                    }
+                    if let Ok(n) = I256::from_dec_str(&fallback_s) {
+                        return Ok(Token::Int(n.into_raw()))
+                    }
                 }
             }
+
             Err(fmt_err!("Unsupported value: {number:?}"))
         }
         Value::String(string) => {

forge/tests/it/repros.rs

@@ -255,3 +255,9 @@ fn test_issue_4630() {
 fn test_issue_4586() {
     test_repro!("Issue4586");
 }
+
+// <https://github.com/foundry-rs/foundry/issues/5038>
+#[test]
+fn test_issue_5038() {
+    test_repro!("Issue5038");
+}

testdata/repros/Issue5038.t.sol

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.18;
+
+import "ds-test/test.sol";
+import "../cheats/Cheats.sol";
+
+struct Value {
+    uint256 value;
+}
+
+// https://github.com/foundry-rs/foundry/issues/5038
+contract Issue5038Test is DSTest {
+    Cheats constant vm = Cheats(HEVM_ADDRESS);
+
+    function testParseMaxUint64() public {
+        string memory json = '{"value": 18446744073709551615}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 18446744073709551615);
+    }
+
+    function testParse18446744073709551616000() public {
+        string memory json = '{"value": 18446744073709551616000}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 18446744073709551616000);
+    }
+
+    function testParse1e19() public {
+        string memory json = '{"value": 10000000000000000000}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 10000000000000000000);
+    }
+
+    function test_parse_1e20() public {
+        string memory json = '{"value": 100000000000000000000}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 100000000000000000000);
+    }
+
+    function testParse1e21() public {
+        string memory json = '{"value": 1000000000000000000000}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 1000000000000000000000);
+    }
+
+    function testParse1e42() public {
+        string memory json = '{"value": 1000000000000000000000000000000000000000000}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 1000000000000000000000000000000000000000000);
+    }
+
+    function testParse1e42plusOne() public {
+        string memory json = '{"value": 1000000000000000000000000000000000000000001}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 1000000000000000000000000000000000000000001);
+    }
+
+    function testParse1e43plus5() public {
+        string memory json = '{"value": 10000000000000000000000000000000000000000005}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 10000000000000000000000000000000000000000005);
+    }
+
+    function testParse1e76() public {
+        string memory json = '{"value": 10000000000000000000000000000000000000000000000000000000000000000000000000000}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 10000000000000000000000000000000000000000000000000000000000000000000000000000);
+    }
+
+    function testParse1e76Plus10() public {
+        string memory json = '{"value": 10000000000000000000000000000000000000000000000000000000000000000000000000010}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 10000000000000000000000000000000000000000000000000000000000000000000000000010);
+    }
+
+    function testParseMinUint256() public {
+        string memory json = '{"value": -57896044618658097711785492504343953926634992332820282019728792003956564819968}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+
+        assertEq(int256(data.value), -57896044618658097711785492504343953926634992332820282019728792003956564819968);
+    }
+
+    function testParseMaxUint256() public {
+        string memory json = '{"value": 115792089237316195423570985008687907853269984665640564039457584007913129639935}';
+        bytes memory parsed = vm.parseJson(json);
+        Value memory data = abi.decode(parsed, (Value));
+        assertEq(data.value, 115792089237316195423570985008687907853269984665640564039457584007913129639935);
+    }
+}