Add `Ci::Runner` inverse_of's

app/models/ci/runner.rb

@@ -12,9 +12,9 @@ module Ci
     FORM_EDITABLE = %i[description tag_list active run_untagged locked access_level maximum_timeout_human_readable].freeze
 
     has_many :builds
-    has_many :runner_projects, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
+    has_many :runner_projects, inverse_of: :runner, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
     has_many :projects, through: :runner_projects
-    has_many :runner_namespaces
+    has_many :runner_namespaces, inverse_of: :runner
     has_many :groups, through: :runner_namespaces
 
     has_one :last_build, ->() { order('id DESC') }, class_name: 'Ci::Build'

app/models/ci/runner_namespace.rb

@@ -2,8 +2,8 @@ module Ci
   class RunnerNamespace < ActiveRecord::Base
     extend Gitlab::Ci::Model
 
-    belongs_to :runner, validate: true
-    belongs_to :namespace, class_name: '::Namespace'
+    belongs_to :runner, inverse_of: :runner_namespaces, validate: true
+    belongs_to :namespace, inverse_of: :runner_namespaces, class_name: '::Namespace'
     belongs_to :group, class_name: '::Group', foreign_key: :namespace_id
   end
 end

app/models/ci/runner_project.rb

@@ -2,8 +2,8 @@ module Ci
   class RunnerProject < ActiveRecord::Base
     extend Gitlab::Ci::Model
 
-    belongs_to :runner
-    belongs_to :project
+    belongs_to :runner, inverse_of: :runner_projects
+    belongs_to :project, inverse_of: :runner_projects
 
     validates :runner_id, uniqueness: { scope: :project_id }
   end

app/models/namespace.rb

@@ -21,7 +21,7 @@ class Namespace < ActiveRecord::Base
   has_many :projects, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
   has_many :project_statistics
 
-  has_many :runner_namespaces, class_name: 'Ci::RunnerNamespace'
+  has_many :runner_namespaces, inverse_of: :namespace, class_name: 'Ci::RunnerNamespace'
   has_many :runners, through: :runner_namespaces, source: :runner, class_name: 'Ci::Runner'
 
   # This should _not_ be `inverse_of: :namespace`, because that would also set

app/models/project.rb

@@ -236,7 +236,7 @@ class Project < ActiveRecord::Base
   has_many :builds, class_name: 'Ci::Build', inverse_of: :project, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
   has_many :build_trace_section_names, class_name: 'Ci::BuildTraceSectionName'
   has_many :build_trace_chunks, class_name: 'Ci::BuildTraceChunk', through: :builds, source: :trace_chunks
-  has_many :runner_projects, class_name: 'Ci::RunnerProject'
+  has_many :runner_projects, class_name: 'Ci::RunnerProject', inverse_of: :project
   has_many :runners, through: :runner_projects, source: :runner, class_name: 'Ci::Runner'
   has_many :variables, class_name: 'Ci::Variable'
   has_many :triggers, class_name: 'Ci::Trigger'