Feature/fileinfo create copy (#9198)

* Initial implementation of a CopyFileInfos function that creates new FileInfo objects copied from provided FileIds with the provided user as the creator and not linked to a post yet. This can subsequently be used to copy existing attachments from another post to attach to a new post without having to re-upload the actual files

* added a unit test for the CopyFileInfos function

* resolving pull request suggestions

3 files changed, 65 insertions, 0 deletions

diff --git a/app/file.go b/app/file.go
index 7dbcdd394..7a642a956 100644
--- a/app/file.go
+++ b/app/file.go
@@ -604,3 +604,33 @@ func (a *App) GetFileInfo(fileId string) (*model.FileInfo, *model.AppError) {
 		return result.Data.(*model.FileInfo), nil
 	}
 }
+
+func (a *App) CopyFileInfos(userId string, fileIds []string) ([]string, *model.AppError) {
+	newFileIds := []string{}
+
+	now := model.GetMillis()
+
+	for _, fileId := range fileIds {
+		fileInfo := &model.FileInfo{}
+
+		if result := <-a.Srv.Store.FileInfo().Get(fileId); result.Err != nil {
+			return nil, result.Err
+		} else {
+			fileInfo = result.Data.(*model.FileInfo)
+		}
+
+		fileInfo.Id = model.NewId()
+		fileInfo.CreatorId = userId
+		fileInfo.CreateAt = now
+		fileInfo.UpdateAt = now
+		fileInfo.PostId = ""
+
+		if result := <-a.Srv.Store.FileInfo().Save(fileInfo); result.Err != nil {
+			return newFileIds, result.Err
+		}
+
+		newFileIds = append(newFileIds, fileInfo.Id)
+	}
+
+	return newFileIds, nil
+}
diff --git a/app/file_test.go b/app/file_test.go
index 23750ad6e..c736328cf 100644
--- a/app/file_test.go
+++ b/app/file_test.go
@@ -161,3 +161,34 @@ func TestMigrateFilenamesToFileInfos(t *testing.T) {
 	infos = th.App.MigrateFilenamesToFileInfos(rpost)
 	assert.Equal(t, 1, len(infos))
 }
+
+func TestCopyFileInfos(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	teamId := model.NewId()
+	channelId := model.NewId()
+	userId := model.NewId()
+	filename := "test"
+	data := []byte("abcd")
+
+	info1, err := th.App.DoUploadFile(time.Date(2007, 2, 4, 1, 2, 3, 4, time.Local), teamId, channelId, userId, filename, data)
+	require.Nil(t, err)
+	defer func() {
+		<-th.App.Srv.Store.FileInfo().PermanentDelete(info1.Id)
+		th.App.RemoveFile(info1.Path)
+	}()
+
+	infoIds, err := th.App.CopyFileInfos(userId, []string{info1.Id})
+	require.Nil(t, err)
+
+	info2, err := th.App.GetFileInfo(infoIds[0])
+	require.Nil(t, err)
+	defer func() {
+		<-th.App.Srv.Store.FileInfo().PermanentDelete(info2.Id)
+		th.App.RemoveFile(info2.Path)
+	}()
+
+	assert.NotEqual(t, info1.Id, info2.Id, "should not be equal")
+	assert.Equal(t, info2.PostId, "", "should be empty string")
+}
diff --git a/app/plugin_api.go b/app/plugin_api.go
index 31bfd401d..c3ab8fab2 100644
--- a/app/plugin_api.go
+++ b/app/plugin_api.go
@@ -275,6 +275,10 @@ func (api *PluginAPI) UpdatePost(post *model.Post) (*model.Post, *model.AppError
 	return api.app.UpdatePost(post, false)
 }
 
+func (api *PluginAPI) CopyFileInfos(userId string, fileIds []string) ([]string, *model.AppError) {
+	return api.app.CopyFileInfos(userId, fileIds)
+}
+
 func (api *PluginAPI) KVSet(key string, value []byte) *model.AppError {
 	return api.app.SetPluginKey(api.id, key, value)
 }