Autocorrect unsafe cops

Special care is needed for `tag.rb` around line 190.
The autofix did not produce a valid result, I had to put extra
curly braces around that line as we want to push an object to the array.

app/controllers/readers_controller.rb

@@ -21,9 +21,8 @@ def update_all
                           .map(&:commontator_thread)
     existing_readers = Reader.where(user: current_user, thread: threads)
     missing_thread_ids = threads.map(&:id) - existing_readers.pluck(:thread_id)
-    new_readers = []
-    missing_thread_ids.each do |t|
-      new_readers << Reader.new(thread_id: t, user: current_user)
+    new_readers = missing_thread_ids.map do |t|
+      Reader.new(thread_id: t, user: current_user)
     end
     Reader.import new_readers
     Reader.where(user: current_user, thread: threads).touch_all

app/models/manuscript.rb

@@ -148,19 +148,16 @@ def create_or_update_chapter_items!
     attrs = [:medium_id, :pdf_destination, :section_id, :sort, :page, :description, :ref_number,
              :position, :quarantine]
     item_details = items.pluck(*attrs).map { |i| attrs.zip(i).to_h }
-    contents = []
-    @chapters.each do |c|
-      contents.push(
-        { medium_id: @medium.id,
-          pdf_destination: c["destination"],
-          section_id: nil,
-          sort: "chapter",
-          page: c["page"].to_i,
-          description: c["description"],
-          ref_number: c["label"],
-          position: nil,
-          quarantine: nil }
-      )
+    contents = @chapters.map do |c|
+      { medium_id: @medium.id,
+        pdf_destination: c["destination"],
+        section_id: nil,
+        sort: "chapter",
+        page: c["page"].to_i,
+        description: c["description"],
+        ref_number: c["label"],
+        position: nil,
+        quarantine: nil }
     end
     create_or_update_items!(contents, item_details, item_destinations,
                             item_id_map)
@@ -176,21 +173,18 @@ def create_or_update_section_items!
     attrs = [:medium_id, :pdf_destination, :section_id, :sort, :page, :description, :ref_number,
              :position, :quarantine]
     item_details = items.pluck(*attrs).map { |i| attrs.zip(i).to_h }
-    contents = []
     # NOTE: that sections get a position -1 in order to place them ahead
     # of all content items within themseleves in #script_items_by_position
-    @sections.each do |s|
-      contents.push(
-        { medium_id: @medium.id,
-          pdf_destination: s["destination"],
-          section_id: s["mampf_section"].id,
-          sort: "section",
-          page: s["page"].to_i,
-          description: s["description"],
-          ref_number: s["label"],
-          position: -1,
-          quarantine: nil }
-      )
+    contents = @sections.map do |s|
+      { medium_id: @medium.id,
+        pdf_destination: s["destination"],
+        section_id: s["mampf_section"].id,
+        sort: "section",
+        page: s["page"].to_i,
+        description: s["description"],
+        ref_number: s["label"],
+        position: -1,
+        quarantine: nil }
     end
     create_or_update_items!(contents, item_details, item_destinations,
                             item_id_map)
@@ -208,22 +202,19 @@ def create_or_update_content_items!(filter_boxes)
     attrs = [:medium_id, :pdf_destination, :section_id, :sort, :page, :description, :ref_number,
              :position, :hidden, :quarantine]
     item_details = items.pluck(*attrs).map { |i| attrs.zip(i).to_h }
-    contents = []
-    @content.each do |c|
-      contents.push(
-        { medium_id: @medium.id,
-          pdf_destination: c["destination"],
-          section_id: @sections.find do |s|
-                        c["section"] == s["section"]
-                      end ["mampf_section"]&.id,
-          sort: Item.internal_sort(c["sort"]),
-          page: c["page"].to_i,
-          description: c["description"],
-          ref_number: c["label"],
-          position: c["counter"],
-          hidden: filter_boxes[c["counter"]].third == false,
-          quarantine: nil }
-      )
+    contents = @content.map do |c|
+      { medium_id: @medium.id,
+        pdf_destination: c["destination"],
+        section_id: @sections.find do |s|
+                      c["section"] == s["section"]
+                    end ["mampf_section"]&.id,
+        sort: Item.internal_sort(c["sort"]),
+        page: c["page"].to_i,
+        description: c["description"],
+        ref_number: c["label"],
+        position: c["counter"],
+        hidden: filter_boxes[c["counter"]].third == false,
+        quarantine: nil }
     end
     create_or_update_items!(contents, item_details, item_destinations,
                             item_id_map)

app/models/medium_publisher.rb

@@ -128,13 +128,12 @@ def realize_optional_stuff!
     # to the medium's teachable's media_scope
     def create_notifications!
       @medium.teachable&.media_scope&.touch
-      notifications = []
       @medium.teachable.media_scope.users.touch_all
-      @medium.teachable.media_scope.users.each do |u|
-        notifications << Notification.new(recipient: u,
-                                          notifiable_id: @medium.id,
-                                          notifiable_type: "Medium",
-                                          action: "create")
+      notifications = @medium.teachable.media_scope.users.map do |u|
+        Notification.new(recipient: u,
+                         notifiable_id: @medium.id,
+                         notifiable_type: "Medium",
+                         action: "create")
       end
       Notification.import notifications
     end

app/models/quiz.rb

@@ -115,7 +115,7 @@ def preselected_hide_solution(vertex_id, crosses)
 
   def questions
     ids = quiz_graph&.vertices&.values&.select { |v| v[:type] == "Question" }
-                    &.map { |v| v[:id] }
+                    &.pluck(:id)
     Question.where(id: ids)
   end
 

app/models/submission.rb

@@ -63,7 +63,7 @@ def correction_size
   end
 
   def preceding_tutorial(user)
-    assignment.previous&.map { |a| a.tutorial(user) }&.compact&.first
+    assignment.previous&.filter_map { |a| a.tutorial(user) }&.first
   end
 
   def invited_users

app/models/tag.rb

@@ -184,13 +184,11 @@ def self.select_by_title_except(excluded_tags)
   # converts the subgraph of all tags of distance <= 2 to the given marked tag
   # into a cytoscape array representing this subgraph
   def self.to_cytoscape(tags, marked_tag, highlight_related_tags: true)
-    result = []
     # add vertices
-    tags.each do |t|
-      result.push(data: t.cytoscape_vertex(marked_tag,
-                                           highlight_related_tags:
-                                             highlight_related_tags))
+    result = tags.map do |t|
+      { data: t.cytoscape_vertex(marked_tag, highlight_related_tags: highlight_related_tags) }
     end
+
     # add edges
     edges = []
     tags.each do |t|