remove missing files and folders on update

app/services/db_folder/update_folder.rb

@@ -7,6 +7,12 @@ class UpdateFolder
   def initialize(folder, entries)
     @folder = folder
     @entries = entries
+    # initialiaze array of current entries, ids are removed
+    # as they are updated, so any id's left in this
+    # array are no longer present on the remote db
+    # and will be destroyed
+    @subfolder_ids = folder.subfolders.ids
+    @file_ids = folder.db_files.ids
     super()
   end
 
@@ -18,6 +24,20 @@ class UpdateFolder
       info.slice(*DbFolder.defined_attributes))
     # process the contents of the folder
     __parse_folder_entries(@folder, @entries)
+    # delete any files or folders still in the
+    # tracked ID arrays, they haven't been touched
+    # so they must have been removed from the remote
+    # db some other way (eg nilmtool)
+    unless @file_ids.empty?
+      @folder.db_files.destroy(*@file_ids)
+      add_warning('Removed files no longer in the remote database')
+    end
+
+    unless @subfolder_ids.empty?
+      @folder.subfolders.destroy(*@subfolder_ids)
+      add_warning('Removed folders no longer in the remote database')
+    end
+
     # save the result
     @folder.save!
     self
@@ -103,14 +123,16 @@ class UpdateFolder
                    default_name)
     base = __base_entry(entry_group)
     unless base # corrupt file, don't process
-      @warnings << "#{entry_group.count} orphan decimations in #{folder.name}"
+      add_warning("#{entry_group.count} orphan decimations in #{folder.name}")
       return
     end
     # find or create the file
     file = folder.db_files.find_by_path(base[:path])
     file ||= DbFile.new(db_folder: folder,
                         path: base[:path], name: default_name)
-
+    # remove the id (if present) to mark this file as updated
+    @file_ids -= [file.id]
+    # return the Updater, don't run it
     UpdateFile.new(file, base, entry_group - [base])
   end
 
@@ -131,6 +153,9 @@ class UpdateFolder
     path = __build_path(entries)
     folder = parent.subfolders.find_by_path(path)
     folder ||= DbFolder.new(parent: parent, path: path, name: default_name)
+    # remove the id (if present) to mark this folder as updated
+    @subfolder_ids -= [folder.id]
+    # return the Updater, don't run it
     UpdateFolder.new(folder, entries)
   end
 

app/services/service_status.rb

@@ -22,6 +22,8 @@ module ServiceStatus
   end
 
   def add_error(message)
+    # ignore duplicates
+    return if @errors.include?(message)
     @errors << String(message)
   end
 
@@ -30,6 +32,8 @@ module ServiceStatus
   end
 
   def add_warning(message)
+    # ignore duplicates
+    return if @warnings.include?(message)
     @warnings << String(message)
   end
 

spec/services/db/update_db_spec.rb

@@ -25,12 +25,12 @@ simple_db = [
 
 describe 'UpdateDb' do
   describe '*run*' do
-    def update_with_schema(schema)
+    def update_with_schema(schema, db: nil)
       # stub the database adapter
       adapter = instance_double(DbAdapter)
       allow(adapter).to receive(:schema).and_return(Array.new(schema))
       # run the update
-      @db = Db.new
+      @db = db || Db.new
       @service = UpdateDb.new(db: @db)
       @service.run(db_adapter: adapter)
       @root = @db.root_folder
@@ -129,8 +129,41 @@ describe 'UpdateDb' do
 
     # updates to remote db
     describe 'given changes to remote db' do
-      it 'removes missing files'
-      it 'removes missing folders'
+      it 'removes missing files' do
+        # create Db with a file 'temp'
+        update_with_schema([helper.entry('/folder1/temp'),
+                            helper.entry('/folder1/info',
+                                         metadata: { name: 'f1' })
+                            ])
+        temp = DbFile.find_by_name('temp')
+        # the file 'temp' should be here
+        expect(temp).to be_present
+        # update Db without 'temp'
+        update_with_schema([helper.entry('/folder1/info',
+                                         metadata: { name: 'f1' })
+                            ], db: @db)
+        # it should be gone
+        expect(DbFile.find_by_name('temp')).to be nil
+        # ...and the service should have a warning
+        expect(@service.warnings?).to be true
+      end
+      it 'removes missing folders' do
+        # create Db with a folder 'temp'
+        update_with_schema([helper.entry('/folder1/stub'),
+                            helper.entry('/folder1/temp/info',
+                                         metadata: { name: 'temp' })
+                            ])
+        temp = DbFolder.find_by_name('temp')
+        # the file 'temp' should be here
+        expect(temp).to be_present
+        # update Db without 'temp'
+        update_with_schema([helper.entry('/folder1/stub')],
+                           db: @db)
+        # it should be gone
+        expect(DbFolder.find_by_name('temp')).to be nil
+        # ...and the service should have a warning
+        expect(@service.warnings?).to be true
+      end
       it 'adds new files'
       it 'adds new folders'
     end

spec/services/service_status_spec.rb

@@ -26,6 +26,13 @@ describe 'ServiceStatus' do
     expect(x.warnings.length).to eq(1)
   end
 
+  it 'ignores duplicate messages' do
+    x = ModuleTester.new
+    x.add_error('the same thing')
+    x.add_error('the same thing')
+    expect(x.errors.length).to eq(1)
+  end
+
   it 'raises error if *run* is not implemented' do
     x = ModuleTester.new
     expect { x.run }.to raise_error(RuntimeError)