Merge pull request #4049 from danielparks/issue-3785-derive-id-attr

fix(derive): Add "id" attribute

clap_derive/src/attrs.rs

@@ -400,7 +400,7 @@ impl Attrs {
     }
 
     fn push_method(&mut self, name: Ident, arg: impl ToTokens) {
-        if name == "name" {
+        if name == "name" || name == "id" {
             self.name = Name::Assigned(quote!(#arg));
         } else if name == "value_parser" {
             self.value_parser = Some(ValueParser::Explicit(Method::new(name, quote!(#arg))));

src/_derive/mod.rs

@@ -181,7 +181,7 @@
 //! - e.g. `#[clap(max_values(3))]` would translate to `arg.max_values(3)`
 //!
 //! **Magic attributes**:
-//! - `name = <expr>`: [`Arg::id`][crate::Arg::id]
+//! - `id = <expr>`: [`Arg::id`][crate::Arg::id]
 //!   - When not present: case-converted field name is used
 //! - `value_parser [= <expr>]`: [`Arg::value_parser`][crate::Arg::value_parser]
 //!   - When not present: will auto-select an implementation based on the field type using

tests/derive/naming.rs

@@ -57,6 +57,34 @@ fn test_standalone_long_ignores_afterwards_defined_custom_name() {
     );
 }
 
+#[test]
+fn test_standalone_long_uses_previous_defined_custom_id() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[clap(id = "foo", long)]
+        foo_option: bool,
+    }
+
+    assert_eq!(
+        Opt { foo_option: true },
+        Opt::try_parse_from(&["test", "--foo"]).unwrap()
+    );
+}
+
+#[test]
+fn test_standalone_long_ignores_afterwards_defined_custom_id() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[clap(long, id = "foo")]
+        foo_option: bool,
+    }
+
+    assert_eq!(
+        Opt { foo_option: true },
+        Opt::try_parse_from(&["test", "--foo-option"]).unwrap()
+    );
+}
+
 #[test]
 fn test_standalone_short_generates_kebab_case() {
     #[derive(Parser, Debug, PartialEq)]
@@ -114,6 +142,34 @@ fn test_standalone_short_ignores_afterwards_defined_custom_name() {
     );
 }
 
+#[test]
+fn test_standalone_short_uses_previous_defined_custom_id() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[clap(id = "option", short)]
+        foo_option: bool,
+    }
+
+    assert_eq!(
+        Opt { foo_option: true },
+        Opt::try_parse_from(&["test", "-o"]).unwrap()
+    );
+}
+
+#[test]
+fn test_standalone_short_ignores_afterwards_defined_custom_id() {
+    #[derive(Parser, Debug, PartialEq)]
+    struct Opt {
+        #[clap(short, id = "option")]
+        foo_option: bool,
+    }
+
+    assert_eq!(
+        Opt { foo_option: true },
+        Opt::try_parse_from(&["test", "-f"]).unwrap()
+    );
+}
+
 #[test]
 fn test_standalone_long_uses_previous_defined_casing() {
     #[derive(Parser, Debug, PartialEq)]