Wrote a custom iterator to convert CRLF to LF

Author: wada314

tests/system.rs

@@ -17,7 +17,9 @@ extern crate term;
 use std::collections::HashMap;
 use std::fs;
 use std::io::{self, BufRead, BufReader, Read};
+use std::iter::Peekable;
 use std::path::{Path, PathBuf};
+use std::str::Bytes;
 
 use rustfmt::*;
 use rustfmt::filemap::{write_system_newlines, FileMap};
@@ -369,8 +371,8 @@ fn handle_result(
         let read_error = format!("Failed reading target {:?}", &target);
         f.read_to_string(&mut text).expect(&read_error);
 
-        // Compare line by line, for Windows machines using CRLF newline.
-        if fmt_text.replace("\r\n", "\n") != text.replace("\r\n", "\n") {
+        // Ignore LF and CRLF difference for Windows.
+        if !string_eq_ignore_newline_repr(&fmt_text, &text) {
             let diff = make_diff(&text, &fmt_text, DIFF_CONTEXT_SIZE);
             assert!(
                 !diff.is_empty(),
@@ -431,3 +433,33 @@ fn rustfmt_diff_no_diff_test() {
     let diff = make_diff("a\nb\nc\nd", "a\nb\nc\nd", 3);
     assert_eq!(diff, vec![]);
 }
+
+// Compare strings without distinguishing between CRLF and LF
+fn string_eq_ignore_newline_repr(left: &str, right: &str) -> bool {
+    let left = BytesIgnoreNewlineRepr(left.bytes().peekable());
+    let right = BytesIgnoreNewlineRepr(right.bytes().peekable());
+    left.eq(right)
+}
+
+struct BytesIgnoreNewlineRepr<'a>(Peekable<Bytes<'a>>);
+
+impl<'a> Iterator for BytesIgnoreNewlineRepr<'a> {
+    type Item = u8;
+    fn next(&mut self) -> Option<u8> {
+        self.0.next().map(|c| if c == b'\r' {
+            if *self.0.peek().unwrap_or(&0) == b'\n' {
+                self.0.next();
+                b'\n'
+            } else {
+                b'\r'
+            }
+        } else {
+            c
+        })
+    }
+}
+
+#[test]
+fn string_eq_ignore_newline_repr_test() {
+    assert!(string_eq_ignore_newline_repr("a\nb\nc\rd", "a\nb\r\nc\rd"));
+}