feat(derive): Add additional group methods

This adds the ability derive additional options for the group creation.
Needed for clap-rs#4574.

clap_derive/src/attr.rs

@@ -86,7 +86,6 @@ impl Parse for ClapAttr {
         let magic = match name_str.as_str() {
             "rename_all" => Some(MagicAttrName::RenameAll),
             "rename_all_env" => Some(MagicAttrName::RenameAllEnv),
-            "required" => Some(MagicAttrName::Required),
             "skip" => Some(MagicAttrName::Skip),
             "next_display_order" => Some(MagicAttrName::NextDisplayOrder),
             "next_help_heading" => Some(MagicAttrName::NextHelpHeading),
@@ -169,7 +168,6 @@ pub enum MagicAttrName {
     Version,
     RenameAllEnv,
     RenameAll,
-    Required,
     Skip,
     DefaultValueT,
     DefaultValuesT,

clap_derive/src/derives/args.rs

@@ -368,7 +368,6 @@ pub fn gen_augment(
         quote!()
     } else {
         let group_id = parent_item.ident().unraw().to_string();
-        let required = parent_item.required_group();
         let literal_group_members = fields
             .iter()
             .filter_map(|(_field, item)| {
@@ -401,11 +400,13 @@ pub fn gen_augment(
             }};
         }
 
+        let group_methods = parent_item.group_methods();
+
         quote!(
             .group(
                 clap::ArgGroup::new(#group_id)
                     .multiple(true)
-                    .required(#required)
+                    #group_methods
                     .args(#literal_group_members)
             )
         )

clap_derive/src/item.rs

@@ -48,8 +48,8 @@ pub struct Item {
     next_help_heading: Option<Method>,
     is_enum: bool,
     is_positional: bool,
-    required_group: bool,
     skip_group: bool,
+    group_methods: Vec<Method>,
     kind: Sp<Kind>,
 }
 
@@ -273,8 +273,8 @@ impl Item {
             next_help_heading: None,
             is_enum: false,
             is_positional: true,
-            required_group: false,
             skip_group: false,
+            group_methods: vec![],
             kind,
         }
     }
@@ -327,7 +327,10 @@ impl Item {
             if name == "short" || name == "long" {
                 self.is_positional = false;
             }
-            self.methods.push(Method::new(name, quote!(#arg)));
+            match kind {
+                AttrKind::Group => self.group_methods.push(Method::new(name, quote!(#arg))),
+                _ => self.methods.push(Method::new(name, quote!(#arg))),
+            };
         }
     }
 
@@ -826,10 +829,6 @@ impl Item {
                     self.env_casing = CasingStyle::from_lit(lit);
                 }
 
-                Some(MagicAttrName::Required) if actual_attr_kind == AttrKind::Group => {
-                    self.required_group = true;
-                }
-
                 Some(MagicAttrName::Skip) if actual_attr_kind == AttrKind::Group => {
                     self.skip_group = true;
                 }
@@ -844,7 +843,6 @@ impl Item {
                 | Some(MagicAttrName::LongHelp)
                 | Some(MagicAttrName::Author)
                 | Some(MagicAttrName::Version)
-                | Some(MagicAttrName::Required)
                  => {
                     let expr = attr.value_or_abort();
                     self.push_method(*attr.kind.get(), attr.name.clone(), expr);
@@ -971,6 +969,11 @@ impl Item {
         quote!( #(#doc_comment)* #(#methods)* )
     }
 
+    pub fn group_methods(&self) -> TokenStream {
+        let group_methods = &self.group_methods;
+        quote!( #(#group_methods)* )
+    }
+
     pub fn deprecations(&self) -> proc_macro2::TokenStream {
         let deprecations = &self.deprecations;
         quote!( #(#deprecations)* )
@@ -1066,10 +1069,6 @@ impl Item {
             .any(|m| m.name != "help" && m.name != "long_help")
     }
 
-    pub fn required_group(&self) -> bool {
-        self.required_group
-    }
-
     pub fn skip_group(&self) -> bool {
         self.skip_group
     }

tests/derive/groups.rs

@@ -127,40 +127,41 @@ fn required_group() {
     struct Opt {
         #[command(flatten)]
         source: Source,
-        #[command(flatten)]
-        dest: Dest,
-    }
 
-    #[derive(clap::Args, Debug)]
-    #[group(required)]
-    struct Source {
-        #[arg(long)]
-        from_path: Option<std::path::PathBuf>,
         #[arg(long)]
-        from_git: Option<String>,
+        alt_source: String,
     }
 
     #[derive(clap::Args, Debug)]
-    #[group(required = true)]
-    struct Dest {
+    #[group(required = true, multiple = false, conflicts_with = "alt_source")]
+    struct Source {
         #[arg(long)]
-        to_path: Option<std::path::PathBuf>,
+        path: Option<std::path::PathBuf>,
         #[arg(long)]
-        to_git: Option<String>,
+        git: Option<String>,
     }
 
+    const OUTPUT: &str = "\
+error: the following required arguments were not provided:
+  --alt-source <ALT_SOURCE>
+  <--path <PATH>|--git <GIT>>
+
+Usage: prog --alt-source <ALT_SOURCE> <--path <PATH>|--git <GIT>>
+
+For more information, try '--help'.
+";
+    assert_output::<Opt>("prog", OUTPUT, true);
+
+    use clap::Args;
+    assert_eq!(Opt::group_id(), Some(clap::Id::from("Opt")));
+    assert_eq!(Source::group_id(), Some(clap::Id::from("Source")));
     use clap::CommandFactory;
     let source_id = clap::Id::from("Source");
-    let dest_id = clap::Id::from("Dest");
     let opt_command = Opt::command();
     let source_group = opt_command
         .get_groups()
         .find(|g| g.get_id() == &source_id)
         .unwrap();
-    let dest_group = opt_command
-        .get_groups()
-        .find(|g| g.get_id() == &dest_id)
-        .unwrap();
     assert!(source_group.is_required_set());
-    assert!(dest_group.is_required_set());
+    // assert!(source_group.is_multiple()); currently broken. Fixed by PR #4704
 }

tests/derive_ui/group_name_attribute.rs

@@ -0,0 +1,23 @@
+use clap::Parser;
+
+#[derive(Parser, Debug)]
+#[command(name = "basic", subcommand)]
+struct Opt {
+    #[command(flatten)]
+    source: Source,
+}
+
+#[derive(clap::Args, Debug)]
+#[group(required = true, name = "src")]
+struct Source {
+    #[arg(short)]
+    git: String,
+
+    #[arg(short)]
+    path: String,
+}
+
+fn main() {
+    let opt = Opt::parse();
+    println!("{:?}", opt);
+}

tests/derive_ui/group_name_attribute.stderr

@@ -0,0 +1,7 @@
+error: `#[group(required = true, name = "src")]` does not support name
+ --> $DIR/group_name_attribute.rs:3:10
+   |
+11 |#[group(required = true, name = "src")]
+   |                         ^^^^^^^^^^^^
+   |
+  = note: this error originates in the derive macro `group` (in Nightly builds, run with -Z macro-backtrace for more info)