What is a reproduction

I made this post to serve as a quick explainer that I or other maintainers can send to newcomers to give them a quick overview of what a reproduction is and why its important.

TLDR: A reproduction is a minimal recreation of the problem in a public repository that does not require including any private code.

In the world of GitHub and open source, a reproduction refers to a minimal, self-contained example that demonstrates a specific issue or bug in software. Think of it as a focused test case that clearly illustrates the problem you’re experiencing without including unnecessary or unrelated code.

Providing a reproduction typically involves creating a small project or code snippet that isolates the issue, making it easy for maintainers or collaborators to understand and investigate. This could be as simple as a single file, a GitHub repository, or even a code sandbox that replicates the issue.

Why Is Providing a Reproduction Important?

1. Facilitates Problem Solving

Maintainers often have limited time to address issues, especially in popular open-source projects. A well-prepared reproduction eliminates guesswork, allowing them to focus directly on diagnosing and fixing the problem.

2. Avoids Miscommunication

Detailed descriptions of an issue are helpful, but written explanations can be subjective or ambiguous. A reproduction removes this ambiguity by showing exactly what the problem looks like in a controlled environment.

3. Speeds Up the Debugging Process

Without a reproduction, maintainers may need to ask follow-up questions, dig through your description, or try to simulate your environment—steps that can significantly delay resolution. A reproduction cuts through this noise.

4. Improves Collaboration

By providing a reproduction, you’re contributing directly to the problem-solving process. It shows respect for the time and effort of maintainers and fosters a collaborative spirit in the open-source community.

How to Create a Reproduction Without Sharing Private Code

A common concern is that sharing a reproduction might expose sensitive or proprietary information. Fortunately, creating a reproduction doesn’t require sharing any private code. Here’s how you can do it safely:

1. Isolate the Problem

Extract only the relevant parts of your code that trigger the issue. For example, if you’re dealing with a React bug, isolate the specific components or logic involved.

2. Use Mock Data

Replace sensitive data with mock or placeholder data. For instance, instead of real API keys or database entries, use dummy values like FAKE_API_KEY or [e-mail].

3. Create a Minimal Example

Strip away anything unnecessary. The goal is to create the simplest possible setup that still reproduces the issue. This reduces complexity and helps maintainers quickly pinpoint the problem.

4. Leverage Public Tools

Tools like CodeSandbox, Replit, or even a minimal GitHub repository can host your reproduction without exposing your private environment. Ideally a public Github repository should be included.

5. Document Your Steps

Clearly describe how to set up and run the reproduction. Include instructions for installing dependencies, running scripts, and observing the issue. This ensures that anyone reviewing the reproduction can easily follow along.

Example of a Minimal Reproduction

Let’s say you’re reporting a bug in a React library where a certain prop causes a crash. Instead of linking your entire app repository, you might create a small project using a simple template and add just the code that reproduces your bug:

import React from 'react';
import { LibraryComponent } from 'example-library';


export default function App() {
  return <LibraryComponent buggyProp="trigger" />;
}

Accompany this with instructions like:

1. Clone the repository.
2. Run npm install to install dependencies.
3. Run npm start and observe the error in the console.

The Bottom Line

Providing a reproduction is an essential part of contributing to open-source projects. It demonstrates respect for the maintainers’ time, improves the likelihood of a speedy resolution, and fosters collaboration. By isolating the issue and avoiding private code, you can provide an effective reproduction while keeping sensitive information safe.

Next time you encounter a bug, consider how you can create a minimal reproduction—it’s a small effort that makes a big difference in the open-source community!