PLT-3105 Files table migration (#4068)

* Implemented initial changes for files table

* Removed *_benchmark_test.go files

* Re-implemented GetPublicFile and added support for old path

* Localization for files table

* Moved file system code into utils package

* Finished server-side changes and added initial upgrade script

* Added getPostFiles api

* Re-add Extension and HasPreviewImage fields to FileInfo

* Removed unused translation

* Fixed merge conflicts left over after permissions changes

* Forced FileInfo.extension to be lower case

* Changed FileUploadResponse to contain the FileInfos instead of FileIds

* Fixed permissions on getFile* calls

* Fixed notifications for file uploads

* Added initial version of client code for files changes

* Permanently added FileIds field to Post object and removed Post.HasFiles

* Updated PostStore.Update to be usable in more circumstances

* Re-added Filenames field and switched file migration to be entirely lazy-loaded

* Increased max listener count for FileStore

* Removed unused fileInfoCache

* Moved file system code back into api

* Removed duplicate test case

* Fixed unit test running on ports other than 8065

* Renamed HasPermissionToPostContext to HasPermissionToChannelByPostContext

* Refactored handleImages to make it more easily understandable

* Renamed getPostFiles to getFileInfosForPost

* Re-added pre-FileIds posts to analytics

* Changed files to be saved as their ids as opposed to id/filename.ext

* Renamed FileInfo.UserId to FileInfo.CreatorId

* Fixed detection of language in CodePreview

* Fixed switching between threads in the RHS not loading new files

* Add serverside protection against a rare bug where the client sends the same file twice for a single post

* Refactored the important parts of uploadFile api call into a function that can be called without a web context

store/sql_channel_store_test.go

@@ -197,6 +197,29 @@ func TestChannelStoreGet(t *testing.T) {
 	}
 }
 
+func TestChannelStoreGetForPost(t *testing.T) {
+	Setup()
+
+	o1 := Must(store.Channel().Save(&model.Channel{
+		TeamId:      model.NewId(),
+		DisplayName: "Name",
+		Name:        "a" + model.NewId() + "b",
+		Type:        model.CHANNEL_OPEN,
+	})).(*model.Channel)
+
+	p1 := Must(store.Post().Save(&model.Post{
+		UserId:    model.NewId(),
+		ChannelId: o1.Id,
+		Message:   "test",
+	})).(*model.Post)
+
+	if r1 := <-store.Channel().GetForPost(p1.Id); r1.Err != nil {
+		t.Fatal(r1.Err)
+	} else if r1.Data.(*model.Channel).Id != o1.Id {
+		t.Fatal("incorrect channel returned")
+	}
+}
+
 func TestChannelStoreDelete(t *testing.T) {
 	Setup()
 
@@ -745,6 +768,39 @@ func TestGetMember(t *testing.T) {
 	}
 }
 
+func TestChannelStoreGetMemberForPost(t *testing.T) {
+	Setup()
+
+	o1 := Must(store.Channel().Save(&model.Channel{
+		TeamId:      model.NewId(),
+		DisplayName: "Name",
+		Name:        "a" + model.NewId() + "b",
+		Type:        model.CHANNEL_OPEN,
+	})).(*model.Channel)
+
+	m1 := Must(store.Channel().SaveMember(&model.ChannelMember{
+		ChannelId:   o1.Id,
+		UserId:      model.NewId(),
+		NotifyProps: model.GetDefaultChannelNotifyProps(),
+	})).(*model.ChannelMember)
+
+	p1 := Must(store.Post().Save(&model.Post{
+		UserId:    model.NewId(),
+		ChannelId: o1.Id,
+		Message:   "test",
+	})).(*model.Post)
+
+	if r1 := <-store.Channel().GetMemberForPost(p1.Id, m1.UserId); r1.Err != nil {
+		t.Fatal(r1.Err)
+	} else if r1.Data.(*model.ChannelMember).ToJson() != m1.ToJson() {
+		t.Fatal("invalid returned channel member")
+	}
+
+	if r2 := <-store.Channel().GetMemberForPost(p1.Id, model.NewId()); r2.Err == nil {
+		t.Fatal("shouldn't have returned a member")
+	}
+}
+
 func TestGetMemberCount(t *testing.T) {
 	Setup()