make formatting commands able to have arguments

config/default.toml

@@ -7,7 +7,7 @@ watch_workspace = true
 show_indent_rulers = true
 always_prompt_on_exit = false
 case_insensitive_search = true
-render_whitespace = "none"
+render_whitespace = "trailing"
 
 [picker]
 show_hidden = false
@@ -25,7 +25,7 @@ padding = 1
 
 [[language]]
 name = "rust"
-format = "rustfmt"
+format = "rustfmt --edition 2021"
 
 [[language]]
 name = "cpp"

crates/ferrite-core/src/buffer/format.rs

@@ -7,7 +7,15 @@ use subprocess::{Exec, PopenError, Redirection};
 use super::{Buffer, Cursor};
 
 fn format(formatter: &str, rope: Rope) -> Result<String, PopenError> {
-    let mut child = Exec::cmd(formatter)
+    let mut parts = formatter.split_whitespace();
+    let Some(first) = parts.next() else {
+        return Err(
+            std::io::Error::new(std::io::ErrorKind::InvalidInput, "invalid formatter").into(),
+        );
+    };
+
+    let mut child = Exec::cmd(first)
+        .args(&parts.collect::<Vec<_>>())
         .stdin(Redirection::Pipe)
         .stdout(Redirection::Pipe)
         .stderr(Redirection::Pipe)