Add non-UTF-8 example; closes #66

examples/non-utf8/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "non-utf8-example"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+dotenvy = { path = "../../dotenvy" }
+encoding_rs_io = "0.1"

examples/non-utf8/src/main.rs

@@ -0,0 +1,35 @@
+//! dotenvy only handles UTF-8.
+//!
+//! If a source file is non-UTF-8, it can still be loaded with help from the `encoding_rs_io` crate.
+
+use dotenvy::EnvLoader;
+use encoding_rs_io::DecodeReaderBytes;
+use std::{
+    error::{self, Error},
+    fs,
+    io::{self, Read},
+};
+
+fn main() -> Result<(), Box<dyn error::Error>> {
+    let path = "env-example-utf16";
+
+    // this will fail
+    let e = EnvLoader::with_path(path).load().unwrap_err();
+    let io_err = e.source().unwrap().downcast_ref::<io::Error>().unwrap();
+    assert_eq!(io_err.kind(), io::ErrorKind::InvalidData);
+
+    // with `encoding_rs_io`, this will work
+    let bytes = fs::read(path)?;
+    let mut decoder = DecodeReaderBytes::new(&bytes[..]);
+    let mut dest = Vec::new();
+
+    // read to end to ensure the stream is fully decoded
+    decoder.read_to_end(&mut dest)?;
+
+    // `path` setter provides the path to error messages
+    let env_map = EnvLoader::with_reader(&dest[..]).path(path).load()?;
+
+    println!("HOST={}", env_map.var("HOST")?);
+
+    Ok(())
+}