Fix parsing of Objective-C block properties (facebook#55776)

Summary:
Pull Request resolved: facebook#55776

Doxygen splits block property types across `<type>` and `<argsstring>` elements. For example:

```objc
property (nonatomic, copy) void (^eventInterceptor)(NSString *eventName, NSDictionary *event, NSNumber *reactTag);
```

Produces XML like:
```xml
<type>void(^</type>
<name>eventInterceptor</name>
<argsstring>)(NSString *eventName, NSDictionary *event, NSNumber *reactTag)</argsstring>
```

This caused the parser to output incomplete types. The fix detects when the property type ends with `(^` and combines it with the property name and argsstring:
```
property (copy) void(^eventInterceptor)(NSString *eventName, NSDictionary *event, NSNumber *reactTag);
```

Changelog:
[Internal]

Reviewed By: cipolleschi

Differential Revision: D94366205

fbshipit-source-id: 2d741401f63916284d453f1112ae0f349234308e

Author: coado

scripts/cxx-api/parser/builders.py

@@ -337,6 +337,16 @@ def get_property_member(
     is_readable = getattr(member_def, "readable", "no") == "yes"
     is_writable = getattr(member_def, "writable", "no") == "yes"
 
+    # Handle block properties: Doxygen splits the block type across <type> and <argsstring>
+    # <type> = "void(^"
+    # <argsstring> = ")(NSString *eventName, NSDictionary *event, NSNumber *reactTag)"
+    # We need to combine them: "void(^eventInterceptor)(NSString *, NSDictionary *, NSNumber *)"
+    if property_type.endswith("(^"):
+        argsstring = member_def.get_argsstring()
+        if argsstring:
+            property_type = f"{property_type}{property_name}{argsstring}"
+            property_name = ""
+
     return PropertyMember(
         property_name,
         property_type,

scripts/cxx-api/parser/member.py

@@ -404,7 +404,11 @@ def to_string(
         if self.is_static:
             result += "static "
 
-        result += f"@property {attrs_str}{self.type} {name};"
+        # For block properties, name is embedded in the type (e.g., "void(^eventInterceptor)(args)")
+        if name:
+            result += f"@property {attrs_str}{self.type} {name};"
+        else:
+            result += f"@property {attrs_str}{self.type};"
 
         return result
 

scripts/cxx-api/tests/snapshots/should_handle_interface_with_block_property/snapshot.api

@@ -0,0 +1,5 @@
+interface RCTInterfaceWithBlockProperty : public NSObject {
+  public @property (copy) NSString *(^blockWithReturn)(int value);
+  public @property (copy) void(^eventInterceptor)(NSString *eventName, NSDictionary *event, NSNumber *reactTag);
+  public @property (copy) void(^simpleBlock)(void);
+}

scripts/cxx-api/tests/snapshots/should_handle_interface_with_block_property/test.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+@interface RCTInterfaceWithBlockProperty : NSObject
+
+@property (nonatomic, copy, nullable) void (^eventInterceptor)
+    (NSString *eventName, NSDictionary *event, NSNumber *reactTag);
+@property (nonatomic, copy) void (^simpleBlock)(void);
+@property (nonatomic, copy) NSString * (^blockWithReturn)(int value);
+
+@end