# MinIO Pull Request Guidelines

These guidelines ensure high-quality commits in MinIO’s GitHub repositories, maintaining 
a clear, valuable commit history for our open-source projects. They apply to all contributors, 
fostering efficient reviews and robust code.

## Why Pull Requests?

Pull Requests (PRs) drive quality in MinIO’s codebase by:
- Enabling peer review without pair programming.
- Documenting changes for future reference.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest

# How To - Recipes { #how-to-recipes }

Here you will see different recipes or "how to" guides for **several topics**.

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

/// tip

# Cluster Metrics

MinIO collects the following metrics at the cluster level.
Metrics may include one or more labels, such as the server that calculated that metric.

These metrics can be obtained from any MinIO server once per collection by using the following URL:

```shell
https://HOSTNAME:PORT/minio/v2/metrics/cluster
```

Replace ``HOSTNAME:PORT`` with the hostname of your MinIO deployment.

        // Assert that the object is not null
        assertNotNull(msrpcLsarClose, "MsrpcLsarClose object should not be null");

        // Verify that the constructor correctly sets ptype and flags
        // These values are inherited from LsarClose, but MsrpcLsarClose sets them in its constructor
        assertEquals(0, msrpcLsarClose.getPtype(), "ptype should be 0");

        hmac.digest(response, 0, 16);
        System.arraycopy(clientChallenge, 0, response, 16, 8);
        return response;
    }

    /**
     * Generate the Unicode MD4 hash for the password associated with these credentials.
     *
     * @param password the password to hash
     * @param challenge the server challenge bytes
     * @return the calculated response

```

 *  Fix: Don't call `EventListener.responseHeadersStart()` or `responseBodyStart()` until bytes have
    been received. Previously these events were incorrectly sent too early, when OkHttp was ready to
    read the response headers or body, which mislead tracing tools. Note that the `responseFailed()`
    event always used to follow one of these events; now it may be sent without them.

 *  New: Upgrade to Kotlin 1.3.61.

    ```kotlin
    if (credential == response.request.header("Authorization")) {
      return null // If we already failed with these credentials, don't retry.
     }
    ```

    }

    @Test
    @DisplayName("Methods should handle null buffer without validation")
    void testMethodsWithNullBuffer() {
        // The implementation doesn't validate null buffers
        // These methods simply return 0 without accessing the buffer

        // Write methods return 0 without accessing null buffer
        assertEquals(0, response.writeSetupWireFormat(null, 0));