Create a separate dev crate for development scripts (#607)

ruff_dev/src/generate_source_code.rs

@@ -0,0 +1,25 @@
+//! Run round-trip source code generation on a given Python file.
+
+use std::path::PathBuf;
+
+use anyhow::Result;
+use clap::Args;
+use ruff::code_gen::SourceGenerator;
+use ruff::fs;
+use rustpython_parser::parser;
+
+#[derive(Args)]
+pub struct Cli {
+    /// Python file to round-trip.
+    #[arg(required = true)]
+    file: PathBuf,
+}
+
+pub fn main(cli: &Cli) -> Result<()> {
+    let contents = fs::read_file(&cli.file)?;
+    let python_ast = parser::parse_program(&contents, &cli.file.to_string_lossy())?;
+    let mut generator = SourceGenerator::new();
+    generator.unparse_suite(&python_ast)?;
+    println!("{}", generator.generate()?);
+    Ok(())
+}