Correctly format files with dos line endings (#81)

* Correctly format files with dos line endings

* Refactor and naming improvements

* Avoid panic on empty file

formatter/src/formatter/mac.rs

@@ -1,5 +1,5 @@
 use crop::Rope;
-use leptosfmt_pretty_printer::Printer;
+use leptosfmt_pretty_printer::{Printer, PrinterSettings};
 use proc_macro2::{token_stream, Span, TokenStream, TokenTree};
 use rstml::node::Node;
 use syn::{spanned::Spanned, Macro};
@@ -155,16 +155,28 @@ pub fn format_macro(
     settings: &FormatterSettings,
     source: Option<&Rope>,
 ) -> String {
-    let mut printer = Printer::new(settings.into());
+    let mut printer: Printer;
     let mut formatter = match source {
         Some(source) => {
             let whitespace = crate::collect_comments::extract_whitespace_and_comments(
                 source,
                 mac.mac.tokens.clone(),
             );
+            let crlf_line_endings = source
+                .raw_lines()
+                .nth(0)
+                .map(|raw_line| raw_line.to_string().ends_with("\r\n"))
+                .unwrap_or_default();
+            printer = Printer::new(PrinterSettings {
+                crlf_line_endings,
+                ..settings.into()
+            });
             Formatter::with_source(*settings, &mut printer, source, whitespace)
         }
-        None => Formatter::new(*settings, &mut printer),
+        None => {
+            printer = Printer::new(settings.into());
+            Formatter::new(*settings, &mut printer)
+        }
     };
 
     formatter.view_macro(mac);

formatter/src/formatter/mod.rs

@@ -54,6 +54,7 @@ impl From<&FormatterSettings> for PrinterSettings {
             margin: value.max_width as isize,
             indent: value.tab_spaces as isize,
             min_space: 60,
+            crlf_line_endings: false,
         }
     }
 }

printer/src/algorithm.rs

@@ -53,6 +53,8 @@ pub struct PrinterSettings {
     pub indent: isize,
     // Every line is allowed at least this much space, even if highly indented.
     pub min_space: isize,
+    // Print CRLF line ending instead of LF
+    pub crlf_line_endings: bool,
 }
 
 pub struct Printer {
@@ -332,6 +334,9 @@ impl Printer {
                 self.print_indent();
                 self.out.push(pre_break);
             }
+            if self.settings.crlf_line_endings {
+                self.out.push('\r');
+            }
             self.out.push('\n');
             let indent = self.indent as isize + token.offset;
             self.pending_indentation = usize::try_from(indent).unwrap();