bug: `vm.parseJson` with static array parses incorrectly

[DavidOrchard]

Component

Forge

Have you ensured that all of these are up to date?

• [X] Foundry
• [X] Foundryup

What version of Foundry are you on?

forge 0.2.0 (08a629a 2023-06-03T00:14:26.563741000Z)

What command(s) is the bug in?

forge test

Operating System

macOS (Apple Silicon)

Describe the bug

Parsing a static sized array fails.

    struct Simple {
        uint256[1] timestamp;
    }

    function testParseJsonStaticArray() public {
        string memory json = '{"timestamp": [1655140035]}';
        bytes memory data = vm.parseJson(json);
        Simple memory fixture = abi.decode(data, (Simple));
        assertEq(fixture.timestamp[0], 1655140035);
}

fails, yet (with dynamically sized array)

  struct Simple {
        uint256[] timestamp;
    }

    function testParseJsonStaticArray() public {
        string memory json = '{"timestamp": [1655140035]}';
        bytes memory data = vm.parseJson(json);
        Simple memory fixture = abi.decode(data, (Simple));
        assertEq(fixture.timestamp[0], 1655140035);
    }

passes

I've forked and made a PR that adds the failing test. https://github.com/foundry-rs/forge-std/pull/422.

I did the fork & branch against forge-std as I'm new to solidity/forge and couldn't get the foundry/forge solidity tests to run.