Goa v3.21.5 Release Notes

Major Architectural Improvements

Eliminated Global Dependencies in Code Generation (#3721)

by @raphael

The code generation architecture has been significantly refactored to remove global state dependencies, improving maintainability and testability:

• Non-global root expressions: Code generation now passes root expressions as parameters instead of relying on global variables
• Restructured ServicesData: Eliminated confusing nested ServicesData structures, creating clear separation between service and transport layer data
• Streamlined file generation: Improved naming conventions and modularity throughout the codebase
• Maintains full backward compatibility - no changes required for existing applications

Bug Fixes

gRPC Streaming Error Handling (#3731)

by @raphael

Fixed a critical issue where gRPC streaming Recv() methods were not properly decoding custom error types:

• Streaming methods now decode errors consistently with unary methods
• Clients can now properly handle custom service errors defined in the DSL
• Applies to all streaming patterns: server, client, and bidirectional
• Fixes issue #3320

Example Generation for UserTypes (#3730)

by @raphael

Corrected example generation for UserTypes to respect validation rules and custom examples:

• UserTypes with format validation (e.g., FormatURI) now generate format-appropriate examples
• Custom examples defined on UserTypes are now properly used
• Fixes issue #3716

HTTP Error Handler Code Generation (#3741)

by @nitinmohan87

Fixed multiple issues in HTTP code generation:

• Properly generate error handler function parameter with validation attributes
• Fixed missing generation of errhandler function in HTTP handlers (since it's optional)
• Improved overall error handling code generation

Type Handling Improvements

• Primitive alias types (#3742) by @raphael: Fixed casting to use underlying types instead of service types (e.g., string instead of UUID) in request building logic
• Import generation (#3744) by @raphael: Added missing import statement generation in certain edge cases
• Example compilation (#3743) by @raphael: Fixed various issues discovered while building the framework examples

OpenAPI Specification Enhancements

Improved MapOf Schema Generation (#3732)

by @fzyukio

Enhanced OpenAPI 3.0 schema generation for MapOf types:

• All map values now have fully-typed schemas regardless of key type
• Replaced ambiguous additionalProperties: true with proper type references
• Improves compatibility with OpenAPI code generators like oapi-codegen
• Maps with non-string keys now generate correct schemas (since OpenAPI only supports string keys)

Code Quality Improvements

Modern Error Handling (#3736)

by @tchssk

Updated generated code to use Go's modern error handling patterns:

• Templates now use errors.Is() for error comparisons
• Improves compatibility with wrapped errors
• Related to issue #3541

Defensive Programming (#3727)

by @nitinmohan87

Added safety checks for nil interceptors:

• Endpoints are now only wrapped with interceptors when they are actually provided
• Prevents potential nil pointer dereferences

New Contributors

• @fzyukio made their first contribution in #3732 🎉

Full Changelog: v3.21.1...v3.21.5