Getting different hash Values for same same input

[sahil-kaushik1]

This is test function

 function testConverttoURI() public view {
        string
            memory svgURI = "data:image/svg+xml;base64,PHN2ZyB2aWV3Qm94PSIwIDAgMjAwIDIwMCIgd2lkdGg9IjQwMCIgaGVpZ2h0PSI0MDAiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHNpcmNsZSBjeD0iMTAwIiBjeT0iMTAwIiBmaWxsPSJyZWQiIHI9Ijc4IiBzdHJva2U9ImJsYWNrIiBzdHJva2Utd2lkdGg9IjMiIC8+PGcgY2xhc3M9ImV5ZXMiPjxjaXJjbGUgY3g9IjcwIiBjeT0iODIiIHI9IjEyIiAvPjxjaXJjbGUgY3g9IjEyNyIgY3k9IjgyIiByPSIxMiIgLz48L2c+PHBhdGggZD0ibTEzNi44MSAxMTYuNTNjLjY5IDI2LjE3LTY0LjExIDQyLTgxLjUyLS43MyIgc3R5bGU9ImZpbGw6bm9uZTsgc3Ryb2tlOiBibGFjazsgc3Ryb2tlLXdpZHRoOiAzMDsgIiAvPjwvc3ZnPg==";
        string
            memory svg = '<svg viewBox="0 0 200 200" width="400" height="400" xmlns="http://www.w3.org/2000/svg"><circle cx="100" cy="100" fill="red" r="78" stroke="black" stroke-width="3" /><g class="eyes"><circle cx="70" cy="82" r="12" /><circle cx="127" cy="82" r="12" /></g><path d="m136.81 116.53c.69 26.17-64.11 42-81.52-.73" style="fill:none; stroke: black; stroke-width: 30; " /></svg>';

        // Get the actual URI from svgToImageURI
        string memory realuri = deploymnft.svgToImageURI(svg);

        // Normalize the strings by trimming any whitespace or newlines
        string memory svgURIclean = string(abi.encodePacked(svgURI));
        string memory realuriClean = string(abi.encodePacked(realuri));

        // Log the raw values
        console.log("svguri", svgURIclean);
        console.log("actualuri", realuriClean);

        console.logBytes(bytes(svgURIclean));
        console.logBytes(bytes(realuriClean));
        console.log("Length of svgURI: ", bytes(svgURIclean).length);
        console.log("Length of actualURI: ", bytes(realuriClean).length);
        // Hash and log both
        bytes32 hash1 = keccak256(abi.encodePacked(svgURIclean));
        bytes32 hash2 = keccak256(abi.encodePacked(realuriClean));

        // Log the hashes using the appropriate function
        console.logBytes32(hash1);
        console.logBytes32(hash2);

        // Assert that the hashes match
        assert(hash1 == hash2);
    }

this is converter function

        string memory baseURL = "data:image/svg+xml;base64,";
        string memory svgBase64Encoded = Base64.encode(bytes(svg)); // Ensure parentheses are correctly closed
        return string(abi.encodePacked(baseURL, svgBase64Encoded));
    }

why for the same input value hash is coming different?

[EngrPips]

Hello @sahil-kaushik1, What I can say is that base64 encoding is highly sensitive, and any slightest change in the input will give a totally different output. Let's look at the example below.

input1 = "boy"
input2 = "boy "

If those two inputs above are not bounded by parenthesis, you may think they are exactly the same, but the input2 has a whitespace at the end. Entering those two inputs into a base64 encoder will give us a different output, and we might be confused as to why.

To cut a long story short, when you get different outputs from a base64 encoder for any two inputs just know those inputs have something different about them.

[sahil-kaushik1]

but their bytess32 format is same and they are having same length too
so where the difference is coming from in base64 hashed values

[EngrPips]

Console.log your svgURI and your realuri to see if they are the same.

[sahil-kaushik1]

u can see the image attached

[EngrPips]

Please help me to help you solve this issue. Do this Console.log your svgURI and your realuri to see if they are the same. Your console shows the value of svgURIclean and realuriClean. Moreover, I can't see the screenshot clearly, send the values so that I can look conveniently.