Add a TagMergePost post-hook (#2010)

* Add a TagMergePost post-hook

Introduce a post-hook for merging tags, call it in the merge path, as
the last thing we do before returning.

pkg/api/resolver_mutation_tag.go

@@ -347,5 +347,6 @@ func (r *mutationResolver) TagsMerge(ctx context.Context, input models.TagsMerge
 		return nil, err
 	}
 
+	r.hookExecutor.ExecutePostHooks(ctx, t.ID, plugin.TagMergePost, input, nil)
 	return t, nil
 }

pkg/plugin/hooks.go

@@ -40,6 +40,7 @@ const (
 
 	TagCreatePost  HookTriggerEnum = "Tag.Create.Post"
 	TagUpdatePost  HookTriggerEnum = "Tag.Update.Post"
+	TagMergePost   HookTriggerEnum = "Tag.Merge.Post"
 	TagDestroyPost HookTriggerEnum = "Tag.Destroy.Post"
 )
 
@@ -74,6 +75,7 @@ var AllHookTriggerEnum = []HookTriggerEnum{
 
 	TagCreatePost,
 	TagUpdatePost,
+	TagMergePost,
 	TagDestroyPost,
 }
 

ui/v2.5/src/components/Changelog/versions/v0120.md

@@ -1,2 +1,5 @@
+### 🎨 Improvements
+* Added plugin hook for Tag merge operation. ([#2010](https://github.com/stashapp/stash/pull/2010))
+
 ### 🐛 Bug fixes
 * Fix "Custom Performer Images" feature picking up non-image files. ([#2017](https://github.com/stashapp/stash/pull/2017))

ui/v2.5/src/docs/en/Plugins.md

@@ -125,6 +125,7 @@ The following operations are supported:
 * `Create`
 * `Update`
 * `Destroy`
+* `Merge` (for `Tag` only)
 
 Currently, only `Post` hook types are supported. These are executed after the operation has completed and the transaction is committed.