SWE-smith: Scaling Data for Software Engineering Agents

You are a software developer doing chaos monkey testing. Your job is to rewrite a function such that it introduces a logical bug that will break existing unit test(s) in a codebase. To this end, some kinds of bugs you might introduce include:

(Per inference call, only 3 of the following tips are randomly selected and shown) 
- Alter calculation order for incorrect results: Rearrange the sequence of operations in a calculation to subtly change the output (e.g., change (a + b) * c to a + (b * c)).
- Introduce subtle data transformation errors: Modify data processing logic, such as flipping a sign, truncating a value, or applying the wrong transformation function.
- Change variable assignments to alter computation state: Assign a wrong or outdated value to a variable that affects subsequent logic.
- Mishandle edge cases for specific inputs: Change handling logic to ignore or improperly handle boundary cases, like an empty array or a null input.
- Modify logic in conditionals or loops: Adjust conditions or loop boundaries (e.g., replace <= with <) to change the control flow.
- Introduce off-by-one errors in indices or loop boundaries: Shift an index or iteration boundary by one, such as starting a loop at 1 instead of 0.
- Adjust default values or constants to affect behavior: Change a hardcoded value or default parameter that alters how the function behaves under normal use.
- Reorder operations while maintaining syntax: Rearrange steps in a process so the function produces incorrect intermediate results without breaking the code.
- Swallow exceptions or return defaults silently: Introduce logic that catches an error but doesn’t log or handle it properly, leading to silent failures.

Tips about the bug-introducing task: (At inference time, tips are randomly shuffled)
- It should not cause compilation errors.
- It should not be a syntax error.
- It should be subtle and challenging to detect.
- It should not modify the function signature.
- It should not modify the documentation significantly.
- For longer functions, if there is an opportunity to introduce multiple bugs, please do!” Please DO NOT INCLUDE COMMENTS IN THE CODE indicating the bug location or the bug itself.

Your answer should be formatted as follows:

Explanation: <explanation>
Bugged Code:
‘‘‘
<bugged code>
‘‘‘

**System Prompt**
You are a software developer and you have been asked to implement a function.  

You will be given the contents of an entire file, with one or more functions defined in it. Please implement the function(s) that are missing. Do NOT modify the function signature, including the function name, parameters, return types, or docstring if provided. Do NOT change any other code in the file. You should not use any external libraries.

**Task Instance Prompt**
Please implement the function func signature in the following code:

{file src code}

Remember, you should not modify the function signature, including the function name, parameters, return types, or docstring if provided. Do NOT change any other code in the file. Format your output as:

[explanation]

{func to write}

You are a software engineer helping to create a realistic dataset of synthetic GitHub issues.

You will be given the following input:

1. Demonstration: A realistic GitHub issue to mimic (included in the <demonstration> tag).
2. Patch: A git diff output/PR changes that introduces a bug (included in the <patch> tag).
3. Test output: The output of running the tests after the patch is applied (included in the <test output> tag).
4. Test source code: Source code for one or more tests that failed (included in the <test source code> tag).

Output: A realistic GitHub issue for the patch.

Guidelines:
- Mimic the style and structure of the demonstration issues. If the demonstration issues are not well structured, your output should also be not well structured. If the demonstrations use improper or no markdown, your output should also use improper or no markdown. If the demonstrations are short/long, your output should also be short/long (if possible). If the demonstrations include human ”flavor text” or ”fluff”, your output should also include human ”flavor text” or ”fluff”. Do this even if it conflicts with your default behavior of trying to be extremely concise and helpful.
- DO NOT explain the fix/what caused the bug itself, focus on how to reproduce the issue it introduces
- Do not mention pytest or what exact test failed. Instead, generate a realistic issue.
- If possible, include information about how to reproduce the issue. An ideal reproduction script should raise an error or print an unexpected output together with the expected output. However, still include this information in a style very similar to the demonstration issues.