fix(protoc-gen-elixir): emit one file per service under one_file_per_module

cmd/protoc-gen-elixir/generator.go

@@ -173,9 +173,10 @@ func renderFileExtensionGroups(files []*descriptorpb.FileDescriptorProto, params
 //     both a service AND a message-embedded extend in the same file, so the
 //     exact service-vs-this-tier relative order is inferred from that
 //     original table, not independently proven.
-//  5. Services (gated on plugins=grpc), in file declaration order, each as a
-//     paired ".Service" + ".Stub" module - rendered after every message body,
-//     verified against testdata/golden/grpc/test/service.pb.ex and
+//  5. Services (gated on plugins=grpc), in file declaration order, each as
+//     one module pairing its ".Service" and ".Stub" defmodules - rendered
+//     after every message body, verified against
+//     testdata/golden/grpc/test/service.pb.ex and
 //     testdata/golden/grpc_proto_source/test/service.pb.ex.
 //
 // The file-level merged PbExtension module is NOT rendered here at all - see
@@ -284,13 +285,14 @@ func (ctx *fileRenderContext) renderEnum(enum *descriptorpb.EnumDescriptorProto,
 
 // renderService renders a single service's paired .Service/.Stub modules
 // given the file's base module name / base package and the service's own
-// SourceCodeInfo path (e.g. [6, i] for file-level service i). The two
-// modules are returned as separate renderedModule entries (each with its own
-// module name) since one_file_per_module=true emits them as two distinct
-// files.
+// SourceCodeInfo path (e.g. [6, i] for file-level service i). The pair is
+// returned as ONE renderedModule keyed by the bare service module name (no
+// .Service/.Stub suffix), matching the escript, which emits both defmodules
+// into a single file derived from that bare name.
 func (ctx *fileRenderContext) renderService(svc *descriptorpb.ServiceDescriptorProto, path []int32) ([]renderedModule, error) {
-	serviceModName := qualifyModName(ctx.baseMod, CamelizeEach(svc.GetName())) + ".Service"
-	stubModName := qualifyModName(ctx.baseMod, CamelizeEach(svc.GetName())) + ".Stub"
+	modName := qualifyModName(ctx.baseMod, CamelizeEach(svc.GetName()))
+	serviceModName := modName + ".Service"
+	stubModName := modName + ".Stub"
 	fullName := qualifyFullName(ctx.basePkg, svc.GetName())
 
 	var docComment string
@@ -309,8 +311,7 @@ func (ctx *fileRenderContext) renderService(svc *descriptorpb.ServiceDescriptorP
 	}
 
 	return []renderedModule{
-		{modName: serviceModName, text: serviceText},
-		{modName: stubModName, text: stubText},
+		{modName: modName, text: serviceText + "\n\n" + stubText},
 	}, nil
 }
 

cmd/protoc-gen-elixir/one_file_per_module_test.go

@@ -63,17 +63,15 @@ func TestOneFilePerModuleIntegration(t *testing.T) {
 	assert.Len(t, resp.GetFile(), len(goldenPaths), "generated file count should match golden fixture count exactly")
 }
 
-// TestOneFilePerModuleWithGRPC guards against a regression where the
-// .Service/.Stub pair was split apart via strings.Cut(text, "\n\n") on
-// RenderService's combined output: the .Service module body itself contains
-// internal blank lines (e.g. after a multi-line @moduledoc, before "use
-// GRPC.Service") that appear before the true Service/Stub boundary, so
-// cutting on the first "\n\n" silently truncated the .Service file and
-// prepended garbage to the .Stub file. There's no golden fixture combining
+// TestOneFilePerModuleWithGRPC guards the escript-matching file layout: the
+// .Service and .Stub defmodules for a given service are emitted together in
+// ONE file, named from the bare service module name (no .Service/.Stub
+// suffix) via Macro.underscore. There's no golden fixture combining
 // one_file_per_module=true with plugins=grpc (gen_goldens.sh never generates
 // one), so this asserts against testdata/golden/grpc/test/service.pb.ex -
-// the proven-correct single-file rendering of the same test.proto/
-// service.proto pair - split at its own known-correct module boundary.
+// the proven-correct rendering of the same test.proto/service.proto pair -
+// which is exactly the expected content here since that fixture already
+// pairs both defmodules in one blob.
 func TestOneFilePerModuleWithGRPC(t *testing.T) {
 	t.Parallel()
 
@@ -88,7 +86,7 @@ func TestOneFilePerModuleWithGRPC(t *testing.T) {
 	resp := testGenerate(t, req)
 	require.Empty(t, resp.GetError())
 
-	wantService := `defmodule Test.TestService.Service do
+	want := `defmodule Test.TestService.Service do
   @moduledoc """
   An example test service that has
   a test method. It expects a Request
@@ -99,17 +97,15 @@ func TestOneFilePerModuleWithGRPC(t *testing.T) {
 
   rpc :test, Test.Request, Test.Reply
 end
-`
-	wantStub := `defmodule Test.TestService.Stub do
+
+defmodule Test.TestService.Stub do
   use GRPC.Stub, service: Test.TestService.Service
 end
 `
 
-	serviceFile, ok := findGeneratedFile(resp.GetFile(), "test/test_service/service.pb.ex")
-	require.True(t, ok, "expected test/test_service/service.pb.ex among generated files")
-	assert.Equal(t, wantService, serviceFile.GetContent())
+	require.Len(t, resp.GetFile(), 1, "service.proto under one_file_per_module should yield exactly the merged service file, with no separate .Service/.Stub files")
 
-	stubFile, ok := findGeneratedFile(resp.GetFile(), "test/test_service/stub.pb.ex")
-	require.True(t, ok, "expected test/test_service/stub.pb.ex among generated files")
-	assert.Equal(t, wantStub, stubFile.GetContent())
+	file, ok := findGeneratedFile(resp.GetFile(), "test/test_service.pb.ex")
+	require.True(t, ok, "expected test/test_service.pb.ex among generated files")
+	assert.Equal(t, want, file.GetContent())
 }