feat: 系统性改进后端测试体系

- 新增 6 个测试场景 (config load pipe, handler errors, service aggregation, engine degradation, openai decoder edges, negative tests)
- 更新测试工具规格 (mockgen, in-memory SQLite)
- 覆盖率目标从 >80% 提升至 >85%
- 新增 test-unit 和 test-integration Makefile 命令
- 新增死代码清理和 mockgen 需求
- 归档变更至 openspec/changes/archive/2026-04-22-improve-backend-testing/

backend/tests/mocks/mock_model_repository.go

@@ -0,0 +1,143 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: model_repo.go
+//
+// Generated by this command:
+//
+//	mockgen -source=model_repo.go -destination=../../tests/mocks/mock_model_repository.go -package=mocks
+//
+
+// Package mocks is a generated GoMock package.
+package mocks
+
+import (
+	domain "nex/backend/internal/domain"
+	reflect "reflect"
+
+	gomock "go.uber.org/mock/gomock"
+)
+
+// MockModelRepository is a mock of ModelRepository interface.
+type MockModelRepository struct {
+	ctrl     *gomock.Controller
+	recorder *MockModelRepositoryMockRecorder
+	isgomock struct{}
+}
+
+// MockModelRepositoryMockRecorder is the mock recorder for MockModelRepository.
+type MockModelRepositoryMockRecorder struct {
+	mock *MockModelRepository
+}
+
+// NewMockModelRepository creates a new mock instance.
+func NewMockModelRepository(ctrl *gomock.Controller) *MockModelRepository {
+	mock := &MockModelRepository{ctrl: ctrl}
+	mock.recorder = &MockModelRepositoryMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockModelRepository) EXPECT() *MockModelRepositoryMockRecorder {
+	return m.recorder
+}
+
+// Create mocks base method.
+func (m *MockModelRepository) Create(model *domain.Model) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Create", model)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Create indicates an expected call of Create.
+func (mr *MockModelRepositoryMockRecorder) Create(model any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Create", reflect.TypeOf((*MockModelRepository)(nil).Create), model)
+}
+
+// Delete mocks base method.
+func (m *MockModelRepository) Delete(id string) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Delete", id)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Delete indicates an expected call of Delete.
+func (mr *MockModelRepositoryMockRecorder) Delete(id any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Delete", reflect.TypeOf((*MockModelRepository)(nil).Delete), id)
+}
+
+// FindByProviderAndModelName mocks base method.
+func (m *MockModelRepository) FindByProviderAndModelName(providerID, modelName string) (*domain.Model, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "FindByProviderAndModelName", providerID, modelName)
+	ret0, _ := ret[0].(*domain.Model)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// FindByProviderAndModelName indicates an expected call of FindByProviderAndModelName.
+func (mr *MockModelRepositoryMockRecorder) FindByProviderAndModelName(providerID, modelName any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "FindByProviderAndModelName", reflect.TypeOf((*MockModelRepository)(nil).FindByProviderAndModelName), providerID, modelName)
+}
+
+// GetByID mocks base method.
+func (m *MockModelRepository) GetByID(id string) (*domain.Model, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetByID", id)
+	ret0, _ := ret[0].(*domain.Model)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// GetByID indicates an expected call of GetByID.
+func (mr *MockModelRepositoryMockRecorder) GetByID(id any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetByID", reflect.TypeOf((*MockModelRepository)(nil).GetByID), id)
+}
+
+// List mocks base method.
+func (m *MockModelRepository) List(providerID string) ([]domain.Model, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "List", providerID)
+	ret0, _ := ret[0].([]domain.Model)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// List indicates an expected call of List.
+func (mr *MockModelRepositoryMockRecorder) List(providerID any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "List", reflect.TypeOf((*MockModelRepository)(nil).List), providerID)
+}
+
+// ListEnabled mocks base method.
+func (m *MockModelRepository) ListEnabled() ([]domain.Model, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ListEnabled")
+	ret0, _ := ret[0].([]domain.Model)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// ListEnabled indicates an expected call of ListEnabled.
+func (mr *MockModelRepositoryMockRecorder) ListEnabled() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ListEnabled", reflect.TypeOf((*MockModelRepository)(nil).ListEnabled))
+}
+
+// Update mocks base method.
+func (m *MockModelRepository) Update(id string, updates map[string]any) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Update", id, updates)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Update indicates an expected call of Update.
+func (mr *MockModelRepositoryMockRecorder) Update(id, updates any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Update", reflect.TypeOf((*MockModelRepository)(nil).Update), id, updates)
+}