refactor(derive): Further generalize kind errors

clap-rs · Sep 2, 2022 · dbdd449 · dbdd449
1 parent 97ce0c4
commit dbdd449
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Showing 5 changed files with 50 additions and 67 deletions.
diff --git a/clap_derive/src/derives/args.rs b/clap_derive/src/derives/args.rs
@@ -72,6 +72,13 @@ pub fn gen_for_struct(
     generics: &Generics,
     fields: &[(&Field, Item)],
 ) -> TokenStream {
+    if !matches!(&*item.kind(), Kind::Command(_)) {
+        abort! { item.kind().span(),
+            "`{}` cannot be used with `command`",
+            item.kind().name(),
+        }
+    }
+
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
     let constructor = gen_constructor(fields);
@@ -194,12 +201,9 @@ pub fn gen_augment(
     let args = fields.iter().filter_map(|(field, item)| {
         let kind = item.kind();
         match &*kind {
-            Kind::Command(ty)
-            | Kind::Value(ty) => {
-                abort!(ty.span(), "Invalid attribute are for arguments")
-            }
-
-            Kind::Subcommand(_)
+            Kind::Command(_)
+            | Kind::Value(_)
+            | Kind::Subcommand(_)
             | Kind::Skip(_)
             | Kind::FromGlobal(_)
             | Kind::ExternalSubcommand => None,
@@ -341,14 +345,12 @@ pub fn gen_constructor(fields: &[(&Field, Item)]) -> TokenStream {
         let kind = item.kind();
         let arg_matches = format_ident!("__clap_arg_matches");
         match &*kind {
-            Kind::Command(ty)
-            | Kind::Value(ty) => {
-                abort!(ty.span(), "Invalid attribute are for arguments")
-            }
-
-            Kind::ExternalSubcommand => {
+            Kind::Command(_)
+            | Kind::Value(_)
+            | Kind::ExternalSubcommand => {
                 abort! { kind.span(),
-                    "`external_subcommand` can be used only on enum variants"
+                    "`{}` cannot be used with `arg`",
+                    kind.name(),
                 }
             }
             Kind::Subcommand(ty) => {
@@ -414,14 +416,12 @@ pub fn gen_updater(fields: &[(&Field, Item)], use_self: bool) -> TokenStream {
         let arg_matches = format_ident!("__clap_arg_matches");
 
         match &*kind {
-            Kind::Command(ty)
-            | Kind::Value(ty) => {
-                abort!(ty.span(), "Invalid attribute are for arguments")
-            }
-
-            Kind::ExternalSubcommand => {
+            Kind::Command(_)
+            | Kind::Value(_)
+            | Kind::ExternalSubcommand => {
                 abort! { kind.span(),
-                    "`external_subcommand` can be used only on enum variants"
+                    "`{}` cannot be used with `arg`",
+                    kind.name(),
                 }
             }
             Kind::Subcommand(ty) => {

diff --git a/clap_derive/src/derives/subcommand.rs b/clap_derive/src/derives/subcommand.rs
@@ -52,6 +52,13 @@ pub fn gen_for_enum(
     generics: &Generics,
     variants: &[(&Variant, Item)],
 ) -> TokenStream {
+    if !matches!(&*item.kind(), Kind::Command(_)) {
+        abort! { item.kind().span(),
+            "`{}` cannot be used with `command`",
+            item.kind().name(),
+        }
+    }
+
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
     let from_arg_matches = gen_from_arg_matches(variants);

diff --git a/clap_derive/src/derives/value_enum.rs b/clap_derive/src/derives/value_enum.rs
@@ -42,6 +42,13 @@ pub fn derive_value_enum(input: &DeriveInput) -> TokenStream {
 }
 
 pub fn gen_for_enum(item: &Item, item_name: &Ident, variants: &[(&Variant, Item)]) -> TokenStream {
+    if !matches!(&*item.kind(), Kind::Value(_)) {
+        abort! { item.kind().span(),
+            "`{}` cannot be used with `value`",
+            item.kind().name(),
+        }
+    }
+
     let lits = lits(variants);
     let value_variants = gen_value_variants(&lits);
     let to_possible_value = gen_to_possible_value(item, &lits);

diff --git a/clap_derive/src/item.rs b/clap_derive/src/item.rs
@@ -103,19 +103,8 @@ impl Item {
                 "`action` attribute is only allowed on fields"
             );
         }
-        match &*res.kind {
-            Kind::Command(_) | Kind::Value(_) | Kind::Arg(_) => res,
-            Kind::Subcommand(_) | Kind::Skip(_) | Kind::FromGlobal(_) | Kind::Flatten => abort!(
-                res.kind.span(),
-                "`{}` is only allowed on fields",
-                res.kind.name(),
-            ),
-            Kind::ExternalSubcommand => abort!(
-                res.kind.span(),
-                "`{}` is only allowed on variants",
-                res.kind.name(),
-            ),
-        }
+
+        res
     }
 
     pub fn from_subcommand_variant(
@@ -155,8 +144,6 @@ impl Item {
                 res.doc_comment = vec![];
             }
 
-            Kind::ExternalSubcommand => (),
-
             Kind::Subcommand(_) => {
                 if let Some(value_parser) = res.value_parser.as_ref() {
                     abort!(
@@ -207,15 +194,13 @@ impl Item {
 
                 res.kind = Sp::new(Kind::Subcommand(ty), res.kind.span());
             }
-            Kind::Skip(_) => (),
-            Kind::FromGlobal(_) => {
-                abort!(
-                    res.kind.span(),
-                    "`{}` is only allowed on fields",
-                    res.kind.name(),
-                )
-            }
-            Kind::Command(_) | Kind::Value(_) | Kind::Arg(_) => (),
+
+            Kind::ExternalSubcommand
+            | Kind::FromGlobal(_)
+            | Kind::Skip(_)
+            | Kind::Command(_)
+            | Kind::Value(_)
+            | Kind::Arg(_) => (),
         }
 
         res
@@ -250,20 +235,8 @@ impl Item {
                 "`action` attribute is only allowed on fields"
             );
         }
-        match &*res.kind {
-            Kind::Command(_) | Kind::Value(_) | Kind::Arg(_) => res,
-            Kind::Skip(_) => res,
-            Kind::Subcommand(_) | Kind::FromGlobal(_) | Kind::Flatten => abort!(
-                res.kind.span(),
-                "`{}` is only allowed on fields",
-                res.kind.name(),
-            ),
-            Kind::ExternalSubcommand => abort!(
-                res.kind.span(),
-                "`{}` is only allowed on variants",
-                res.kind.name(),
-            ),
-        }
+
+        res
     }
 
     pub fn from_args_field(
@@ -309,12 +282,6 @@ impl Item {
                 res.doc_comment = vec![];
             }
 
-            Kind::ExternalSubcommand => abort!(
-                res.kind.span(),
-                "`{}` is only allowed on variants",
-                res.kind.name(),
-            ),
-
             Kind::Subcommand(_) => {
                 if let Some(value_parser) = res.value_parser.as_ref() {
                     abort!(
@@ -366,7 +333,7 @@ impl Item {
                 let ty = Ty::from_syn_ty(&field.ty);
                 res.kind = Sp::new(Kind::FromGlobal(ty), orig_ty.span());
             }
-            Kind::Command(_) | Kind::Value(_) | Kind::Arg(_) => {
+            Kind::Arg(_) => {
                 let ty = Ty::from_syn_ty(&field.ty);
 
                 match *ty {
@@ -403,6 +370,8 @@ impl Item {
                         .unwrap_or_else(|| field.ty.span()),
                 );
             }
+
+            Kind::Command(_) | Kind::Value(_) | Kind::ExternalSubcommand => {}
         }
 
         res
@@ -1153,7 +1122,7 @@ pub enum Kind {
 }
 
 impl Kind {
-    fn name(&self) -> &'static str {
+    pub fn name(&self) -> &'static str {
         match self {
             Self::Arg(_) => "arg",
             Self::Command(_) => "command",

diff --git a/tests/derive_ui/struct_subcommand.stderr b/tests/derive_ui/struct_subcommand.stderr
@@ -1,4 +1,4 @@
-error: `subcommand` is only allowed on fields
+error: `subcommand` cannot be used with `command`
   --> tests/derive_ui/struct_subcommand.rs:12:24
    |
 12 | #[clap(name = "basic", subcommand)]