Print stats when formatting trees

src/format.rs

@@ -24,7 +24,7 @@ pub fn string(
 pub fn file(
     config: &crate::config::Config,
     path: String,
-) -> std::io::Result<()> {
+) -> std::io::Result<bool> {
     use std::io::Write;
 
     let input = std::fs::read_to_string(&path)?;
@@ -34,9 +34,10 @@ pub fn file(
     let output = crate::format::string(config, path.clone(), input);
     let output_bytes = output.as_bytes();
 
-    if input_bytes != output_bytes {
+    let changed = input_bytes != output_bytes;
+    if changed {
         std::fs::File::create(path)?.write_all(output_bytes)?;
     }
 
-    Ok(())
+    Ok(changed)
 }

src/main.rs

@@ -14,17 +14,25 @@ fn main() -> std::io::Result<()> {
 
             eprintln!("Formatting {} files.", paths.len());
 
-            for result in paths
+            let (results, errors): (Vec<_>, Vec<_>) = paths
                 .par_iter()
-                .map(|path| -> std::io::Result<()> {
+                .map(|path| -> std::io::Result<bool> {
-                    eprintln!("Formatting: {}", &path);
+                    alejandra::format::file(&config, path.to_string()).map(
-                    alejandra::format::file(&config, path.to_string())?;
+                        |changed| {
-                    Ok(())
+                            if changed {
+                                eprintln!("Formatted: {}", &path);
+                            }
+                            changed
+                        },
+                    )
                 })
-                .collect::<Vec<std::io::Result<()>>>()
+                .partition(Result::is_ok);
-            {
+            eprintln!(
-                result?;
+                "Errors/Changed/Formatted: {}/{}/{}",
-            }
+                errors.len(),
+                results.into_iter().map(Result::unwrap).filter(|&x| x).count(),
+                paths.len()
+            );
         }
         None => {
             eprintln!("Formatting stdin.");