Non-idempotent with empty line at beginning of file and wrong identation
Open
Nobody has claimed this yet.
C-bug
I-non-idempotency
I-poor-formatting
I-poor-indentation
S-has-mcve
- Dominant language
- Rust
- Stars
- 7k
- Forks
- 1.1k
- Avg merge
- 2d 13h
- Merged PRs (30d)
- 24
Description
With defaults, given an empty line plus a wrongly indented item on the next line, e.g. (using non-Rust formatting to avoid the Markdown renderer removing the first empty line):
use a;
The first pass gives:
use a;
The second pass gives:
use a;
Reproduces with:
rustfmt 1.8.0-stable (1159e78c47 2025-09-14)
rustfmt 1.8.0-nightly (be0ade2b60 2025-10-11)
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the issue with rustfmt 1.8.0 using a file that begins with an empty line followed by an indented use a;. Compare the first and second formatting passes; done means formatting the input is idempotent and preserves the expected leading blank-line behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- tooling
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100