io-providers

Defines "provider" traits and implementations for different types of I/O operations.

• Documentation: https://pshendry.github.io/io-providers/io_providers/
• Crate information: https://crates.io/crates/io-providers

The purpose of this is mainly for dependency injection: by having your code depend on a generic provider, it can be tested by giving it a virtual, inspectable implementation of that provider. In production, the "real" implementation can be used.

Example

Cargo.toml:

[dependencies] io-providers = "0.1"

src/main.rs

```rust extern crate io_providers;

use std::io::Write; use std::path::Path; use ioproviders::{IoProvider, LocalIoProvider, VirtualIoProvider}; use ioproviders::env::Provider as EnvProvider; use io_providers::stream::Provider as StreamProvider;

/// Gets the current working directory and prints it to stdout. fn dowork(io: &mut IoProvider) { let curdir = io.env().currentdir().unwrap(); let stdout = io.stream().output(); writeln!( stdout, "The current directory is: {}", curdir.to_str().unwrap()) .unwrap(); }

fn main() { testdoworkprintscurrent_dir();

// Use a local I/O provider here to get real interaction with the system
let mut io = LocalIoProvider::new();
do_work(&mut io);

}

fn testdoworkprintscurrentdir() { // Use a virtual I/O provider here so we can verify how it was used let mut virtualio = VirtualIoProvider::new(); virtualio.env().setcurrent_dir(Path::new("/foo/bar")).unwrap();

do_work(&mut virtual_io);

assert_eq!(
    "The current directory is: /foo/bar\n",
    ::std::str::from_utf8(virtual_io.virtual_stream().read_output()).unwrap());

} ```

License

io-providers is distributed under the MIT license.