[GUILD-314] Add find with filter method

repo.go

@@ -124,6 +124,28 @@ func (r *Repo) FindAll(ctx context.Context) ([]eh.Entity, error) {
 	return result, nil
 }
 
+// FindWithFilter allows to find entities with a filter
+func (r *Repo) FindWithFilter(ctx context.Context, expr string, args ...interface{}) ([]eh.Entity, error) {
+	if r.factoryFn == nil {
+		return nil, eh.RepoError{
+			Err:       ErrModelNotSet,
+			Namespace: eh.NamespaceFromContext(ctx),
+		}
+	}
+
+	table := r.service.Table(r.config.TableName)
+
+	iter := table.Scan().Filter(expr, args...).Consistent(true).Iter()
+	result := []eh.Entity{}
+	entity := r.factoryFn()
+	for iter.Next(entity) {
+		result = append(result, entity)
+		entity = r.factoryFn()
+	}
+
+	return result, nil
+}
+
 // Save implements the Save method of the eventhorizon.WriteRepo interface.
 func (r *Repo) Save(ctx context.Context, entity eh.Entity) error {
 	table := r.service.Table(r.config.TableName)

repo_test.go

@@ -136,6 +136,22 @@ func (suite *RepoTestSuite) TestSaveAndFindAll() {
 	assert.Equal(suite.T(), 2, len(results))
 }
 
+func (suite *RepoTestSuite) TestSaveAndFindWithFilter() {
+	testModel := &TestModel{ID: uuid.New(), Content: "test", FilterableID: 123}
+	testModel2 := &TestModel{ID: uuid.New(), Content: "test2", FilterableID: 123}
+	testModel3 := &TestModel{ID: uuid.New(), Content: "test3", FilterableID: 456}
+
+	err := suite.repo.Save(context.Background(), testModel)
+	suite.repo.Save(context.Background(), testModel2)
+	suite.repo.Save(context.Background(), testModel3)
+
+	results, err := suite.repo.FindWithFilter(context.Background(), "FilterableID = ?", 123)
+	if err != nil {
+		suite.T().Fatal("error finding entity:", err)
+	}
+	assert.Equal(suite.T(), 2, len(results))
+}
+
 func (suite *RepoTestSuite) TestRemove() {
 	testModel := &TestModel{ID: uuid.New(), Content: "test"}
 
@@ -177,8 +193,9 @@ func (suite *RepoTestSuite) TestParent() {
 }
 
 type TestModel struct {
-	ID      uuid.UUID `dynamo:",hash"`
-	Content string
+	ID           uuid.UUID `dynamo:",hash"`
+	Content      string
+	FilterableID int
 }
 
 // EntityID implements the EntityID method of the eventhorizon.Entity interface.