Format generated code with prettyplease

Cargo.toml

@@ -146,6 +146,7 @@ path_serde = { path = "crates/path_serde" }
 path_serde_derive = { path = "crates/path_serde_derive" }
 petgraph = "0.6.2"
 png = "0.17.6"
+prettyplease = "0.2.19"
 proc-macro-error = "1.0.4"
 proc-macro2 = { version = "1.0.44", features = ["span-locations"] }
 projection = { path = "crates/projection" }

crates/code_generation/Cargo.toml

@@ -8,6 +8,7 @@ homepage.workspace = true
 [dependencies]
 convert_case = { workspace = true }
 itertools = { workspace = true }
+prettyplease = { workspace = true }
 proc-macro2 = { workspace = true }
 quote = { workspace = true }
 source_analyzer = { workspace = true }

crates/code_generation/src/write_to_file.rs

@@ -3,7 +3,6 @@ use std::{
     fs::File,
     io::{self, Write},
     path::{Path, PathBuf},
-    process::Command,
 };
 
 use proc_macro2::TokenStream;
@@ -15,27 +14,23 @@ pub enum Error {
     Environment(#[from] VarError),
     #[error("failed to perform io")]
     Io(#[from] io::Error),
-    #[error("failed to run rustfmt")]
-    RustFmt,
+    #[error("failed to parse token stream")]
+    Parse(#[from] syn::Error),
 }
 
 pub trait WriteToFile {
-    fn write_to_file(&self, file_name: impl AsRef<Path>) -> Result<(), Error>;
+    fn write_to_file(self, file_name: impl AsRef<Path>) -> Result<(), Error>;
 }
 
 impl WriteToFile for TokenStream {
-    fn write_to_file(&self, file_name: impl AsRef<Path>) -> Result<(), Error> {
+    fn write_to_file(self, file_name: impl AsRef<Path>) -> Result<(), Error> {
+        let syntax_tree = syn::parse2(self)?;
+        let pretty = prettyplease::unparse(&syntax_tree);
+
         let out_dir = var("OUT_DIR")?;
         let file_path = PathBuf::from(out_dir).join(file_name);
-        {
-            let mut file = File::create(&file_path)?;
-            write!(file, "{self}")?;
-        }
-
-        let status = Command::new("rustfmt").arg(file_path).status()?;
-        if !status.success() {
-            return Err(Error::RustFmt);
-        }
+        let mut file = File::create(file_path)?;
+        write!(file, "{pretty}")?;
 
         Ok(())
     }