comm-central/third_party/rust/fs-err/src
Name Description Size Coverage
dir.rs 2669 -
errors.rs 9937 -
file.rs 14944 -
lib.rs ! fs-err is a drop-in replacement for [`std::fs`] that provides more helpful messages on errors. Extra information includes which operations was attempted and any involved paths. # Error Messages Using [`std::fs`], if this code fails: ```no_run # use std::fs::File; let file = File::open("does not exist.txt")?; # Ok::<(), std::io::Error>(()) ``` The error message that Rust gives you isn't very useful: ```txt The system cannot find the file specified. (os error 2) ``` ...but if we use fs-err instead, our error contains more actionable information: ```txt failed to open file `does not exist.txt`: The system cannot find the file specified. (os error 2) ``` # Usage fs-err's API is the same as [`std::fs`], so migrating code to use it is easy. ```no_run // use std::fs; use fs_err as fs; let contents = fs::read_to_string("foo.txt")?; println!("Read foo.txt: {}", contents); # Ok::<(), std::io::Error>(()) ``` fs-err uses [`std::io::Error`] for all errors. This helps fs-err compose well with traits from the standard library like [`std::io::Read`] and crates that use them like [`serde_json`]: ```no_run use fs_err::File; let file = File::open("my-config.json")?; // If an I/O error occurs inside serde_json, the error will include a file path // as well as what operation was being performed. let decoded: Vec<String> = serde_json::from_reader(file)?; println!("Program config: {:?}", decoded); # Ok::<(), Box<dyn std::error::Error>>(()) ``` # Feature flags `expose_original_error`: when enabled, the [`std::error::Error::source`] method of errors returned by this crate return the original [`std::io::Error`]. To avoid duplication in error messages, this also suppresses printing its message in their `Display` implementation, so make sure that you are printing the full error chain. `debug`: Debug filesystem errors faster by exposing more information. When a filesystem command fails, the error message might say "file does not exist." But it won't say **why** it doesn't exist. Perhaps the programmer misspelled the filename, perhaps that directory doesn't exist, or if it does, but the current user doesn't have permissions to see the contents. This feature analyzes the filesystem to output various "facts" that will help a developer debug the root of the current error. Warning: Exposes filesystem metadata. This feature exposes additional metadata about your filesystem such as directory contents and permissions, which may be sensitive. Only enable `debug` when error messages won't be displayed to the end user, or they have access to filesystem metadata some other way. Warning: This may slow down your program. This feature will trigger additional filesystem calls when errors occur, which may cause performance issues. Do not use if filesystem errors are common on a performance-sensitive "hotpath." Use in scenarios where developer hours are more expensive than compute time. To mitigate performance and security concerns, consider only enabling this feature in `dev-dependencies`: Requires Rust 1.79 or later ```toml [dev-dependencies] fs-err = { features = ["debug"] } ``` To use with the `tokio` feature, use `debug_tokio`: ```toml [dependencies] fs-err = { features = ["debug_tokio", "tokio"] } ``` # Minimum Supported Rust Version The oldest rust version this crate is tested on is **1.40**. This crate will generally be conservative with rust version updates. It uses the [`autocfg`] crate to allow wrapping new APIs without incrementing the MSRV. If the `tokio` feature is enabled, this crate will inherit the MSRV of the selected [`tokio`] version. [`autocfg`]: https://crates.io/crates/autocfg [`serde_json`]: https://crates.io/crates/serde_json [`tokio`]: https://crates.io/crates/tokio 11981 -
open_options.rs 4640 -
os -
os.rs OS-specific functionality. 366 -
path.rs 2412 -
tokio -