Hex validator returns invalid hex string

[martinboksa]

Issue workflow progress

Progress of the issue based on the Contributor Workflow

• 1. The issue provides a reproduction available on GitHub, Stackblitz or CodeSandbox

Make sure to fork this template and run yarn generate in the terminal.

Please make sure the GraphQL Scalars package version under package.json matches yours.

• 2. A failing test has been provided
• 3. A local solution has been provided
• 4. A pull request is pending review

---

Describe the bug
I tried to send 'hex' data to graphql server and store them in database (as BYTEA column in postgre) but hexValidator always returns an error.

IDK why is not working properly, maybe the fix could be to update hexValidator() function into regexp.

To Reproduce
https://codesandbox.io/p/sandbox/sweet-gianmarco-1bldd6?file=%2Fsrc%2Findex.ts

    const binaryData = new Uint8Array([
      1, 3, 255, 184, 227, 157, 8, 0, 7, 1, 7, 100, 101, 102, 97, 117, 108, 116,
      3, 13, 100, 111, 99, 117, 109, 101, 110, 116, 84, 105, 116, 108, 101, 7,
      0, 255, 184, 227, 157, 8, 0, 6, 4, 0, 255, 184, 227, 157, 8, 1, 1, 97, 0,
    ])

    const hex = Buffer.from(
      binaryData.buffer,
      binaryData.byteOffset,
      binaryData.length
    ).toString('hex')

    hexValidator(hex) is false

Environment:

• OS: Mac
• GraphQL Scalars Version: 1.20.1

[Urigo]

Hi @martinboksa and thank you for the report

Sorry but I'm not adding a lot here but just labeling it according to our new Contribution Guide and issue flow.

It seems already got into stage 1 thanks to your reproduction! Thank you for that!

Now in order to advance to stage 2 we'll need a failing test, would be great if someone could help progress the issues through the stages.

Thank you and sorry that this comment is not a complete solution (yet).

[martinboksa]

By the way, it's because the validator parses the hex string into small slices, and then fn parseInt removes all 'left zeroes' from each slice.

[cinan]

we're using yarn patch as a (rather simplistic) workaround:

diff --git a/cjs/scalars/Byte.js b/cjs/scalars/Byte.js
index e6d3be273a4c77b9e19da28d3cdf3d80d0c75987..beb3936ccd611c92c6bad22c9a3d27daa2d095b7 100644
--- a/cjs/scalars/Byte.js
+++ b/cjs/scalars/Byte.js
@@ -5,18 +5,8 @@ const graphql_1 = require("graphql");
 const error_js_1 = require("../error.js");
 const base64Validator = /^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$/;
 function hexValidator(value) {
-    // Ensure that any leading 0 is removed from the hex string to avoid false negatives.
-    const sanitizedValue = value.charAt(0) === '0' ? value.slice(1) : value;
-    // For larger strings, we run into issues with MAX_SAFE_INTEGER, so split the string
-    // into smaller pieces to avoid this issue.
-    if (value.length > 8) {
-        let parsedString = '';
-        for (let startIndex = 0, endIndex = 8; startIndex < value.length; startIndex += 8, endIndex += 8) {
-            parsedString += parseInt(value.slice(startIndex, endIndex), 16).toString(16);
-        }
-        return parsedString === sanitizedValue;
-    }
-    return parseInt(value, 16).toString(16) === sanitizedValue;
+    const regexp = /^[0-9a-fA-F]+$/;
+    return regexp.test(value)
 }
 function validate(value, ast) {
     if (typeof value !== 'string' && !(value instanceof global.Buffer)) {

[ardatan]

Feel free to create a PR for the fix!