Clippy lint · Suspicious · checked with Clippy 0.1.99

clippy::join_absolute_paths: Checks for calls to Path::join that start with a path separator (\\ or /)

What it meansChecks for calls to Path::join that start with a path separator (\\ or /). It is in the suspicious group and warns by default.

Does it matter?

If the argument to Path::join starts with a separator, it will overwrite the original path. If this is intentional, prefer using Path::new instead. Note the behavior is platform dependent. A leading \\ will be accepted on unix systems as part of the file name See Path::join

Code that is most likely wrong or useless. Warns by default.

How to fix it

Clippy does not fix this one automatically. Change the code by hand:

Flagged

let path = Path::new("/bin");
let joined_path = path.join("/sh");
assert_eq!(joined_path, PathBuf::from("/sh"));

Write this instead

let path = Path::new("/bin");

// If this was unintentional, remove the leading separator
let joined_path = path.join("sh");
assert_eq!(joined_path, PathBuf::from("/bin/sh"));

// If this was intentional, create a new path instead
let new = Path::new("/sh");
assert_eq!(new, PathBuf::from("/sh"));

Turn it off, or on

Allow it where it does not fit your code, as narrowly as you can:

On one item

#[allow(clippy::join_absolute_paths)]
fn my_function() { /* ... */ }

Whole crate (Cargo.toml)

[lints.clippy]
join_absolute_paths = "allow"

One run

cargo clippy -- -A clippy::join-absolute-paths

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.

Suspiciousgroup

warndefault level

nofixed by cargo clippy --fix

1.76.0added in Rust

Clippy's own documentation

What it does

Checks for calls to Path::join that start with a path separator (\\ or /).

Why is this bad?

If the argument to Path::join starts with a separator, it will overwrite the original path. If this is intentional, prefer using Path::new instead.

Note the behavior is platform dependent. A leading \\ will be accepted on unix systems as part of the file name

See Path::join

Example

let path = Path::new("/bin");
let joined_path = path.join("/sh");
assert_eq!(joined_path, PathBuf::from("/sh"));

Use instead;

let path = Path::new("/bin");

// If this was unintentional, remove the leading separator
let joined_path = path.join("sh");
assert_eq!(joined_path, PathBuf::from("/bin/sh"));

// If this was intentional, create a new path instead
let new = Path::new("/sh");
assert_eq!(new, PathBuf::from("/sh"));

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

Up next

Also worth your time

Did this answer your question?