force edition 2024 lint into action on crater

src/bin/cargo/commands/check.rs

@@ -1,7 +1,7 @@
-use crate::command_prelude::*;
-
 use cargo::ops;
 
+use crate::command_prelude::*;
+
 pub fn cli() -> Command {
     subcommand("check")
         // subcommand aliases are handled in aliased_command()
@@ -44,16 +44,62 @@ pub fn cli() -> Command {
 }
 
 pub fn exec(gctx: &mut GlobalContext, args: &ArgMatches) -> CliResult {
+    if std::env::var("CARGO_REAL_CHECK").is_err() {
+        fixit()?;
+        return Ok(());
+    }
     let ws = args.workspace(gctx)?;
     // This is a legacy behavior that causes `cargo check` to pass `--test`.
-    let test = matches!(
-        args.get_one::<String>("profile").map(String::as_str),
-        Some("test")
-    );
+    let test = matches!(args.get_one::<String>("profile").map(String::as_str), Some("test"));
     let mode = CompileMode::Check { test };
     let compile_opts =
         args.compile_options(gctx, mode, Some(&ws), ProfileChecking::LegacyTestOnly)?;
 
     ops::compile(&ws, &compile_opts)?;
     Ok(())
 }
+
+fn fixit() -> CliResult {
+    use std::path::Path;
+
+    use anyhow::Context;
+    use cargo_util::{paths, ProcessBuilder};
+
+    eprintln!("Copying to /tmp/fixit");
+    ProcessBuilder::new("cp").args(&["-a", ".", "/tmp/fixit"]).exec()?;
+    std::env::set_current_dir("/tmp/fixit").map_err(|e| anyhow::format_err!("cd failed {}", e))?;
+
+    let ed_re = regex::Regex::new(r#"(?m)^ *edition *= *['"]([^'"]+)['"]"#).unwrap();
+    let manifest = paths::read(Path::new("Cargo.toml"))?;
+    let ed_cap = match ed_re.captures(&manifest) {
+        None => {
+            eprintln!("no edition found in manifest, probably 2015, skipping");
+            return Ok(());
+        }
+        Some(caps) => caps.get(1).unwrap(),
+    };
+    if ed_cap.as_str() != "2021" {
+        eprintln!("skipping non-2021 edition `{}`", ed_cap.as_str());
+        return Ok(());
+    }
+    eprintln!("Running `cargo fix --edition`");
+    // Skip "cargo check"
+    let args: Vec<_> = std::env::args().skip(2).collect();
+    ProcessBuilder::new("cargo")
+        .args(&["fix", "--edition", "--allow-no-vcs", "--allow-dirty"])
+        .args(&args)
+        .exec()
+        .with_context(|| "failed to migrate to next edition")?;
+    let mut manifest = paths::read(Path::new("Cargo.toml"))?;
+    let ed_cap = ed_re.captures(&manifest).unwrap().get(1).unwrap();
+    manifest.replace_range(ed_cap.range(), "2024");
+    paths::write("Cargo.toml", manifest)?;
+    eprintln!("Running `cargo check` to verify 2024");
+    ProcessBuilder::new("cargo")
+        .args(&["check"])
+        .args(&args)
+        .env("CARGO_REAL_CHECK", "1")
+        .exec()
+        .with_context(|| "failed to check after updating to 2024")?;
+    Ok(())
+}