Add tests for attributes not in meta-item form

Author: ninevra

corpus/declarations.txt

@@ -996,6 +996,93 @@ mod macos_only {
               (identifier)
               value: (string_literal))))))))
 
+================================================================================
+Attribute macros
+================================================================================
+
+foo(#[attr(=> arbitrary tokens <=)] x, y);
+
+foo(#[bar(some tokens are special in other contexts: $/';()*()+.)] x);
+
+--------------------------------------------------------------------------------
+
+(source_file
+  (expression_statement
+    (call_expression
+      function: (identifier)
+      arguments: (arguments
+        (attribute_item (attr_item
+          (identifier)
+          arguments: (delim_token_tree (identifier) (identifier))))
+        (identifier)
+        (identifier))))
+  (expression_statement
+    (call_expression
+      function: (identifier)
+      arguments: (arguments
+        (attribute_item (attr_item
+          (identifier)
+          arguments: (delim_token_tree
+            (identifier)
+            (identifier)
+            (identifier)
+            (identifier)
+            (identifier)
+            (identifier)
+            (identifier)
+            (delim_token_tree)
+            (delim_token_tree))))
+        (identifier)))))
+
+================================================================================
+Derive macro helper attributes
+================================================================================
+
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("first letter must be lowercase but was {:?}", first_char(.0))]
+    WrongCase(String),
+    #[error("invalid index {idx}, expected at least {} and at most {}", .limits.lo, .limits.hi)]
+    OutOfBounds { idx: usize, limits: Limits },
+}
+
+--------------------------------------------------------------------------------
+
+(source_file
+  (use_declaration
+    (scoped_identifier (identifier) (identifier)))
+  (attribute_item
+    (meta_item (identifier)
+      (meta_arguments
+        (meta_item (identifier))
+        (meta_item (identifier)))))
+  (enum_item
+    (visibility_modifier)
+    (type_identifier)
+    (enum_variant_list
+      (attribute_item (attr_item
+        (identifier)
+        (delim_token_tree
+          (string_literal)
+          (identifier)
+          (delim_token_tree (integer_literal)))))
+      (enum_variant (identifier)
+        (ordered_field_declaration_list (type_identifier)))
+      (attribute_item (attr_item
+        (identifier)
+        (delim_token_tree
+          (string_literal)
+          (identifier)
+          (identifier)
+          (identifier)
+          (identifier))))
+      (enum_variant (identifier)
+        (field_declaration_list
+          (field_declaration (field_identifier) (primitive_type))
+          (field_declaration (field_identifier) (type_identifier)))))))
+
 ================================================================================
 Attributes and Expressions
 ================================================================================