Allow dry run of publish

tools/src/main.rs

@@ -6,11 +6,11 @@ fn main() {
     let matches = Command::new("Agb tools")
         .subcommand_required(true)
         .arg_required_else_help(true)
-        .subcommand(clap::Command::new("publish").about("Publishes agb and all subcrates"))
+        .subcommand(publish::command())
         .get_matches();
 
     let result = match matches.subcommand() {
-        Some(("publish", _)) => publish::publish(),
+        Some(("publish", arg_matches)) => publish::publish(arg_matches),
         _ => unreachable!("Exhausted list of subcommands and subcommand_required prevents `None`"),
     };
 

tools/src/publish.rs

@@ -1,3 +1,4 @@
+use clap::{Arg, ArgAction, ArgMatches};
 use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
@@ -21,19 +22,40 @@ pub enum Error {
     CrateVersion,
 }
 
-pub fn publish() -> Result<(), Error> {
+pub fn command() -> clap::Command<'static> {
+    clap::Command::new("publish")
+        .about("Publishes agb and all subcrates")
+        .arg(
+            Arg::new("Dry run")
+                .long("dry-run")
+                .help("Don't actually publish")
+                .action(ArgAction::SetTrue),
+        )
+}
+
+pub fn publish(matches: &ArgMatches) -> Result<(), Error> {
+    let dry_run = matches.get_one::<bool>("Dry run").expect("defined by clap");
+
     let root_directory = find_agb_root_directory()?;
 
     for crate_to_publish in CRATES_TO_PUBLISH.iter() {
         let crate_dir = root_directory.join(crate_to_publish);
-        let publish_result = Command::new("cargo")
-            .arg("publish")
-            .current_dir(&crate_dir)
-            .spawn();
 
-        if let Err(err) = publish_result {
+        if *dry_run {
-            println!("Error while publishing crate {crate_to_publish}: {err}");
+            println!(
-            return Err(Error::PublishCrate);
+                "Would run `cargo publish` in {}",
+                crate_dir.to_string_lossy()
+            );
+        } else {
+            let publish_result = Command::new("cargo")
+                .arg("publish")
+                .current_dir(&crate_dir)
+                .spawn();
+
+            if let Err(err) = publish_result {
+                println!("Error while publishing crate {crate_to_publish}: {err}");
+                return Err(Error::PublishCrate);
+            }
         }
 
         let expected_version = read_cargo_toml_version(&crate_dir)?;