Phase 3 Plan 1: Shared Test Proto Infrastructure Summary

Canonical exhaustive test proto with all annotation types, shared across all 4 generators via symlinks, with proto3 optional support fix

Performance#

Expanded exhaustive test proto with int64/uint64/float/double query params, enums, optional fields, nested messages, and search RPC
Created symlinks from OpenAPI test directory to httpgen canonical test protos (http_verbs_comprehensive, query_params, backward_compat, unwrap)
Fixed proto3 optional field support in protoc-gen-go-http and protoc-gen-go-client plugins
Added 12 new OpenAPI golden test cases for shared proto services
All 4 generators pass with the expanded proto and shared infrastructure

Each task was committed atomically:

Task 1: Expand exhaustive test proto and fix proto3 optional support - 1cd141a (feat/fix)
Task 2: Symlink shared test protos into OpenAPI and update golden infrastructure - a0e69d5 (feat)

internal/openapiv3/testdata/proto/http_verbs_comprehensive.proto - Symlink to httpgen canonical
internal/openapiv3/testdata/proto/query_params.proto - Symlink to httpgen canonical
internal/openapiv3/testdata/proto/backward_compat.proto - Symlink to httpgen canonical
internal/openapiv3/testdata/golden/yaml/RESTfulAPIService.openapi.yaml - Golden file for shared proto
internal/openapiv3/testdata/golden/yaml/BackwardCompatService.openapi.yaml - Golden file for shared proto
internal/openapiv3/testdata/golden/yaml/QueryParamService.openapi.yaml - Golden file for shared proto
internal/openapiv3/testdata/golden/yaml/NoAnnotationsService.openapi.yaml - Golden file for shared proto
internal/openapiv3/testdata/golden/yaml/BasePathOnlyService.openapi.yaml - Golden file for shared proto
internal/openapiv3/testdata/golden/yaml/OptionDataService.openapi.yaml - Golden file for shared proto
Plus corresponding JSON golden files for each

internal/httpgen/testdata/proto/http_verbs_comprehensive.proto - Added enum, nested message, optional fields, int64/uint64/float/double query params, SearchResources RPC
internal/httpgen/testdata/proto/unwrap.proto - Added UnwrapService with root-level unwrap RPCs
internal/openapiv3/testdata/proto/unwrap.proto - Replaced with symlink to httpgen
internal/openapiv3/exhaustive_golden_test.go - Added 12 test cases for shared protos + OptionDataService
cmd/protoc-gen-go-http/main.go - Added proto3 optional SupportedFeatures
cmd/protoc-gen-go-client/main.go - Added proto3 optional SupportedFeatures
All 4 generators' golden files updated for expanded proto

D-03-01-01: Added UnwrapService to httpgen unwrap.proto as a second service (alongside OptionDataService) rather than renaming. This preserves backward compatibility for existing httpgen golden files while enabling OpenAPI root-level unwrap testing.
D-03-01-02: Root-level unwrap RPCs use POST method instead of GET. The httpgen validator correctly enforces that GET requests cannot have body fields. The original OpenAPI unwrap.proto used GET, but that was semantically incorrect.
D-03-01-03: Proto3 optional fields require plugins to declare FEATURE_PROTO3_OPTIONAL in SupportedFeatures. Only tsclientgen and openapiv3 had this; go-http and go-client were missing it.

1. [Rule 1 - Bug] Proto3 optional support missing in go-http and go-client plugins

Found during: Task 1 (expanded proto with optional string tag)
Issue: protoc-gen-go-http and protoc-gen-go-client did not declare FEATURE_PROTO3_OPTIONAL, causing protoc to reject proto files with optional fields
Fix: Added plugin.SupportedFeatures = uint64(pluginpb.CodeGeneratorResponse_FEATURE_PROTO3_OPTIONAL) to both plugins
Files modified: cmd/protoc-gen-go-http/main.go, cmd/protoc-gen-go-client/main.go
Verification: All 4 generators now handle optional fields in proto3
Committed in: 1cd141a (Task 1 commit)

2. [Rule 2 - Missing Critical] UnwrapService missing from httpgen unwrap.proto

Found during: Task 2 (symlinking unwrap.proto to OpenAPI)
Issue: OpenAPI unwrap.proto had UnwrapService with root-level unwrap RPCs; httpgen version only had OptionDataService with one RPC. Symlinking would lose root-level unwrap test coverage.
Fix: Added UnwrapService to httpgen unwrap.proto with all 4 root-level unwrap RPCs, using POST method to satisfy httpgen validation
Files modified: internal/httpgen/testdata/proto/unwrap.proto
Verification: All 4 generators handle the expanded unwrap.proto without errors
Committed in: a0e69d5 (Task 2 commit)

Total deviations: 2 auto-fixed (1 bug, 1 missing critical) Impact on plan: Both auto-fixes necessary for correctness. No scope creep.

Task 1 commit 1cd141a was already present in the repository from a prior session that included the proto expansion and proto3 optional fix. The changes were re-verified to confirm all done criteria were met.
OpenAPI unwrap.proto had different package name and service structure from httpgen version, requiring careful merging rather than simple replacement.

None - no external service configuration required.

All 4 generators now share canonical test protos via symlinks
Expanded exhaustive test proto provides comprehensive coverage for cross-generator consistency auditing in Plan 03-03+
OpenAPI golden test infrastructure expanded to 38 test cases (19 services x 2 formats)
No blockers for subsequent plans

Phase: 03-existing-client-review Completed: 2026-02-05