feat(derive): derive clap::Args for enum types

flake.nix

@@ -0,0 +1,36 @@
+{
+  inputs.fenix = {
+    url = "github:nix-community/fenix";
+    inputs.nixpkgs.follows = "nixpkgs";
+  };
+
+  outputs =
+    { nixpkgs, fenix, ... }:
+    let
+      pkgs = nixpkgs.legacyPackages.aarch64-darwin;
+    in
+    {
+      devShells.aarch64-darwin.default = pkgs.mkShell {
+        shellHook = ''
+          export RUST_SRC_PATH="${pkgs.rustPlatform.rustLibSrc}";
+        '';
+        packages = [
+          pkgs.lldb
+          pkgs.libiconv
+          pkgs.darwin.apple_sdk.frameworks.Security
+          pkgs.darwin.apple_sdk.frameworks.SystemConfiguration
+          (fenix.packages.aarch64-darwin.combine [
+            fenix.packages.aarch64-darwin.stable.cargo
+            fenix.packages.aarch64-darwin.stable.rust
+            fenix.packages.aarch64-darwin.targets.wasm32-wasi.stable.rust-std
+            fenix.packages.aarch64-darwin.targets.wasm32-wasip1.stable.rust-std
+            fenix.packages.aarch64-darwin.targets.aarch64-apple-darwin.stable.rust-std
+          ])
+        ];
+      };
+
+      formatter.aarch64-darwin = pkgs.nixfmt-rfc-style;
+
+    };
+
+}

tests/derive/groups.rs

@@ -239,3 +239,57 @@ For more information, try '--help'.
 ";
     assert_output::<Opt>("test", OUTPUT, true);
 }
+
+#[test]
+fn enum_groups_1() {
+    #[derive(Parser, Debug, PartialEq, Eq)]
+    struct Opt {
+        #[command(flatten)]
+        source: Source,
+    }
+
+    #[derive(clap::Args, Clone, Debug, PartialEq, Eq)]
+    enum Source {
+        A {
+            #[arg(short)]
+            a: bool,
+            #[arg(long)]
+            aaa: bool,
+        },
+        B {
+            #[arg(short)]
+            b: bool,
+        },
+    }
+
+    assert_eq!(
+        Opt {
+            source: Source::A {
+                a: true,
+                aaa: false,
+            }
+        },
+        Opt::try_parse_from(["test", "-a"]).unwrap()
+    );
+    assert_eq!(
+        Opt {
+            source: Source::A { a: true, aaa: true }
+        },
+        Opt::try_parse_from(["test", "-a", "--aaa"]).unwrap()
+    );
+    assert_eq!(
+        Opt {
+            source: Source::B { b: true }
+        },
+        Opt::try_parse_from(["test", "-b"]).unwrap()
+    );
+
+    assert_eq!(
+        clap::error::ErrorKind::ArgumentConflict,
+        Opt::try_parse_from(["test", "-b", "-a"])
+            .unwrap_err()
+            .kind(),
+    );
+
+    // assert_eq!(       )
+}