Canonical: https://instain.ru/en/tasks/explain-code-error/
Language: en

Practical task

# Understand a code error

How to prepare a reproducible example, ask for a minimal fix and test it in a separate working copy of the project.

Code Code 

## How to approach the task

- Prepare your source material and remove any information that must not be sent to the selected service.

- Select the appropriate mode and check the access conditions on the official page.

- Use the sample brief as a starting point, then check the result against the listed criteria.

## Suitable tools

Matching a tool to a task does not guarantee the quality of a particular result. Open the tool pages, check the terms and compare limitations.

Assistants 

###  [DeepSeek](https://instain.ru/en/ai/deepseek/)

Conversation and reasoning, with a separate API for developers

4.43 / 5   service  

Code 

###  [GitHub Copilot](https://instain.ru/en/ai/github-copilot/)

Coding assistance within the editor and development workflow

4.73 / 5   service  

Code 

###  [Cursor](https://instain.ru/en/ai/cursor/)

AI editor and agent that works with the context of the project

4.58 / 5   editor  

Code 

###  [Codex](https://instain.ru/en/ai/openai-codex/)

An AI assistant that works on your project and checks changes

4.78 / 5   service  

From task to first result

## Practical example

Task

Understand a code error

What to prepare

Code

### Task brief or prompt

Explain why this function handles an empty list incorrectly. First describe its current behavior, then suggest a minimal fix and checks for empty, normal and invalid input. Do not change other parts of the project unnecessarily.

### Expected result

An explanation of the cause, a small proposed diff and checks to run locally.

### How to check the result

- Read the diff before applying it.

- Run the checks in a separate working copy and make sure no secrets were included in the prompt.

This is an editorial learning scenario, not the results of comparative testing. Check the relevant mode’s capabilities and limitations on the tool page and in the official help.