# Description
This PR fixes a bug that occurs if you pass `rename --column` and empty
list like `ls | rename -c []`.
## Before
```
> ls | rename -c []
thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', crates\nu-command\src\filters\rename.rs:110:15
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
## After
```
> ls | rename -c []
Error: nu:🐚:type_mismatch (link)
× Type mismatch.
╭─[entry #1:1:1]
1 │ ls | rename -c []
· ─┬
· ╰── The list cannot be empty and must contain only two values: the column's name and its replacement value
╰────
```
# User-Facing Changes
_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
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