feat: guard new config format behind hidden flag

We now opt into the new configuration format via `cargo dist init --opt-in-migrate`.
Users who don't pass this flag won't have the new format offered to them. Users with
an already-initted project will be asked if they want to opt in, while users with a
Cargo.toml project will be automatically given the new format.

cargo-dist/src/cli.rs

@@ -275,6 +275,9 @@ pub struct InitArgs {
     /// `cargo dist init` will persist the values you pass to that location.
     #[clap(long, value_delimiter(','))]
     pub hosting: Vec<HostingStyle>,
+    /// Opts into the new configuration format
+    #[clap(long, hide = true)]
+    pub opt_in_migrate: bool,
 }
 
 /// Which style(s) of configuration to generate
@@ -377,6 +380,9 @@ pub struct UpdateArgs {
     /// `cargo dist init` will persist the values you pass to that location.
     #[clap(long, value_delimiter(','))]
     pub hosting: Vec<HostingStyle>,
+    /// Opts into the new configuration format
+    #[clap(long, hide = true)]
+    pub opt_in_migrate: bool,
 }
 
 /// A style of CI to generate

cargo-dist/src/init.rs

@@ -26,6 +26,8 @@ pub struct InitArgs {
     pub with_json_config: Option<Utf8PathBuf>,
     /// Hosts to enable
     pub host: Vec<HostingStyle>,
+    /// Whether to migrate to the new config format
+    pub migrate_to_new_config: bool,
 }
 
 /// Input for --with-json-config
@@ -104,34 +106,37 @@ pub fn do_init(cfg: &Config, args: &InitArgs) -> DistResult<()> {
     // If this is a Cargo.toml, offer to either write their config to
     // a dist-workspace.toml, or migrate existing config there
     let mut is_migrating = false;
+    let mut newly_initted_generic = false;
     // Users who haven't initted yet should be opted into the
     // new config format by default.
-    let desired_workspace_kind = if root_workspace.kind == WorkspaceKind::Rust && !initted {
-        WorkspaceKind::Generic
-    // Already-initted users should be asked whether to migrate.
-    } else if root_workspace.kind == WorkspaceKind::Rust {
-        let prompt = r#"Would you like to opt in to the new configuration format?
+    let desired_workspace_kind =
+        if root_workspace.kind == WorkspaceKind::Rust && !initted && args.migrate_to_new_config {
+            newly_initted_generic = true;
+            WorkspaceKind::Generic
+        // Already-initted users should be asked whether to migrate.
+        } else if root_workspace.kind == WorkspaceKind::Rust && args.migrate_to_new_config {
+            let prompt = r#"Would you like to opt in to the new configuration format?
     Future versions of cargo-dist will feature major changes to the
     configuration format, including a new cargo-dist-specific configuration file."#;
-        let res = if args.yes {
-            // We want to avoid --yes pulling it in at this point.
-            false
-        } else {
-            dialoguer::Confirm::with_theme(&theme())
-                .with_prompt(prompt)
-                .default(false)
-                .interact()?
-        };
+            let res = if args.yes {
+                // We want to avoid --yes pulling it in at this point.
+                false
+            } else {
+                dialoguer::Confirm::with_theme(&theme())
+                    .with_prompt(prompt)
+                    .default(args.migrate_to_new_config)
+                    .interact()?
+            };
 
-        if res {
-            is_migrating = true;
-            WorkspaceKind::Generic
+            if res {
+                is_migrating = true;
+                WorkspaceKind::Generic
+            } else {
+                root_workspace.kind
+            }
         } else {
             root_workspace.kind
-        }
-    } else {
-        root_workspace.kind
-    };
+        };
 
     let multi_meta = if let Some(json_path) = &args.with_json_config {
         // json update path, read from a file and apply all requested updates verbatim
@@ -154,7 +159,7 @@ pub fn do_init(cfg: &Config, args: &InitArgs) -> DistResult<()> {
     // If we're migrating, the configuration will be missing the
     // generic workspace specification, and will have some
     // extraneous cargo-specific stuff that we don't want.
-    let mut workspace_toml = if is_migrating || !initted {
+    let mut workspace_toml = if is_migrating || newly_initted_generic {
         // Always generate a new workspace here for the !initted case
         let mut new_workspace = toml_edit::DocumentMut::new();
 
@@ -190,7 +195,7 @@ pub fn do_init(cfg: &Config, args: &InitArgs) -> DistResult<()> {
     let destination;
     // If we're migrating, *or* if we're doing a first-time init,
     // calculate the filename to write to
-    if is_migrating || !initted {
+    if is_migrating || newly_initted_generic {
         filename = match desired_workspace_kind {
             WorkspaceKind::Rust => "Cargo.toml",
             WorkspaceKind::Generic | WorkspaceKind::Javascript => "dist-workspace.toml",

cargo-dist/src/main.rs

@@ -303,6 +303,7 @@ fn cmd_init(cli: &Cli, args: &InitArgs) -> Result<(), miette::Report> {
         no_generate: args.skip_generate,
         with_json_config: args.with_json_config.clone(),
         host: args.hosting.iter().map(|host| host.to_lib()).collect(),
+        migrate_to_new_config: args.opt_in_migrate,
     };
     do_init(&config, &args)?;
     Ok(())