feat: replace service field with a function

This commit replaces the `service` field on the config struct,
with a function for getting the service to be tested.
This is a preparation for upcomming commit.

internal/plugin/resource.go

@@ -41,10 +41,12 @@ func (r *resourceGenerator) generateFixture(f *protogen.GeneratedFile) {
 	})
 
 	f.P("type ", resourceTestSuiteConfigName(r.service.Desc, r.resource), " struct {")
-	f.P("service ", service)
 	f.P("currParent int")
 	f.P()
 
+	f.P("// Service should return the service that should be tested.")
+	f.P("// The service will be used for several tests.")
+	f.P("Service", " func() ", service)
 	f.P("// Context should return a new context.")
 	f.P("// The context will be used for several tests.")
 	f.P("Context", " func() ", context)

internal/plugin/service.go

@@ -60,13 +60,17 @@ func (s *serviceGenerator) generateTestMethods(f *protogen.GeneratedFile) {
 		GoName:       "T",
 		GoImportPath: "testing",
 	})
+	service := f.QualifiedGoIdent(protogen.GoIdent{
+		GoName:       s.service.GoName + "Server",
+		GoImportPath: s.service.Methods[0].Input.GoIdent.GoImportPath,
+	})
 	serviceFx := serviceTestSuiteName(s.service.Desc)
 	for _, resource := range s.resources {
 		resourceFx := resourceTestSuiteConfigName(s.service.Desc, resource)
 		f.P("func (fx ", serviceFx, ") Test", resourceType(resource), "(ctx ", context, ", options ", resourceFx, ") {")
 		f.P("fx.T.Run(", strconv.Quote(resourceType(resource)), ", func(t *", testingT, ") {")
 		f.P("options.Context = func() ", context, " { return ctx }")
-		f.P("options.service = fx.Server")
+		f.P("options.Service = func() ", service, " { return fx.Server", "}")
 		f.P("options.test(t)")
 		f.P("})")
 		f.P("}")

internal/util/method.go

@@ -25,7 +25,7 @@ func (m MethodCreate) Generate(f *protogen.GeneratedFile, response, err, assign
 		f.P("}")
 	}
 
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	if HasParent(m.Resource) {
 		f.P("Parent: ", m.Parent, ",")
 	}
@@ -59,7 +59,7 @@ type MethodGet struct {
 }
 
 func (m MethodGet) Generate(f *protogen.GeneratedFile, response, err, assign string) {
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	f.P("Name: ", m.Name, ",")
 	f.P("})")
 }
@@ -73,7 +73,7 @@ type MethodBatchGet struct {
 }
 
 func (m MethodBatchGet) Generate(f *protogen.GeneratedFile, response, err, assign string) {
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	if HasParent(m.Resource) {
 		f.P("Parent: ", m.Parent, ",")
 	}
@@ -111,7 +111,7 @@ func (m MethodUpdate) Generate(f *protogen.GeneratedFile, response, err, assign
 		}
 		f.P("msg.Name = ", m.Name)
 	}
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	if m.Msg != "" {
 		f.P(upper, ":", m.Msg, ",")
 	} else {
@@ -154,7 +154,7 @@ type MethodList struct {
 }
 
 func (m MethodList) Generate(f *protogen.GeneratedFile, response, err, assign string) {
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	if HasParent(m.Resource) {
 		f.P("Parent: ", m.Parent, ",")
 	}
@@ -177,7 +177,7 @@ type MethodSearch struct {
 }
 
 func (m MethodSearch) Generate(f *protogen.GeneratedFile, response, err, assign string) {
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	if HasParent(m.Resource) {
 		f.P("Parent: ", m.Parent, ",")
 	}
@@ -200,7 +200,7 @@ type MethodDelete struct {
 }
 
 func (m MethodDelete) Generate(f *protogen.GeneratedFile, response, err, assign string) {
-	f.P(response, ", ", err, " ", assign, " fx.service.", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{")
+	f.P(response, ", ", err, " ", assign, " fx.Service().", m.Method.GoName, "(fx.Context(), &", m.Method.Input.GoIdent, "{") //nolint:lll
 	if m.Name != "" {
 		f.P("Name: ", m.Name, ",")
 	} else {