Disable Webhooks before proceeding with the GitHub import

lib/gitlab/github_import/hook_formatter.rb

+module Gitlab
+  module GithubImport
+    class HookFormatter
+      EVENTS = %w[* create delete pull_request push].freeze
+
+      attr_reader :raw
+
+      delegate :id, :name, :active, to: :raw
+
+      def initialize(raw)
+        @raw = raw
+      end
+
+      def config
+        raw.config.attrs
+      end
+
+      def valid?
+        (EVENTS & raw.events).any? && active
+      end
+    end
+  end
+end

lib/gitlab/github_import/importer.rb

@@ -69,6 +69,9 @@ module Gitlab
       end
       def import_pull_requests
+        hooks = client.hooks(repo).map { |raw| HookFormatter.new(raw) }.select(&:valid?)
+        disable_webhooks(hooks)
+
         pull_requests = client.pull_requests(repo, state: :all, sort: :created, direction: :asc)
                               .map { |raw| PullRequestFormatter.new(project, raw) }
                               .select(&:valid?)
@@ -77,7 +80,7 @@ module Gitlab
         target_branches_removed = pull_requests.reject(&:target_branch_exists?).map { |pr| [pr.target_branch_name, pr.target_branch_sha] }
         branches_removed = source_branches_removed | target_branches_removed
-        create_refs(branches_removed)
+        restore_branches(branches_removed)
         pull_requests.each do |pull_request|
           merge_request = MergeRequest.new(pull_request.attributes)
@@ -93,10 +96,25 @@ module Gitlab
       rescue ActiveRecord::RecordInvalid => e
         raise Projects::ImportService::Error, e.message
       ensure
-        delete_refs(branches_removed)
+        clean_up_restored_branches(branches_removed)
+        clean_up_disabled_webhooks(hooks)
+      end
+
+      def disable_webhooks(hooks)
+        update_webhooks(hooks, active: false)
+      end
+
+      def clean_up_disabled_webhooks(hooks)
+        update_webhooks(hooks, active: true)
+      end
+
+      def update_webhooks(hooks, options)
+        hooks.each do |hook|
+          client.edit_hook(repo, hook.id, hook.name, hook.config, options)
+        end
       end
-      def create_refs(branches)
+      def restore_branches(branches)
         branches.each do |name, sha|
           client.create_ref(repo, "refs/heads/#{name}", sha)
         end
@@ -104,7 +122,7 @@ module Gitlab
         project.repository.fetch_ref(repo_url, '+refs/heads/*', 'refs/heads/*')
       end
-      def delete_refs(branches)
+      def clean_up_restored_branches(branches)
         branches.each do |name, _|
           client.delete_ref(repo, "heads/#{name}")
           project.repository.rm_branch(project.creator, name)

spec/lib/gitlab/github_import/hook_formatter_spec.rb

+require 'spec_helper'
+
+describe Gitlab::GithubImport::HookFormatter, lib: true do
+  describe '#id' do
+    it 'returns raw id' do
+      raw = double(id: 100000)
+      formatter = described_class.new(raw)
+      expect(formatter.id).to eq 100000
+    end
+  end
+
+  describe '#name' do
+    it 'returns raw id' do
+      raw = double(name: 'web')
+      formatter = described_class.new(raw)
+      expect(formatter.name).to eq 'web'
+    end
+  end
+
+  describe '#config' do
+    it 'returns raw config.attrs' do
+      raw = double(config: double(attrs: { url: 'http://something.com/webhook' }))
+      formatter = described_class.new(raw)
+      expect(formatter.config).to eq({ url: 'http://something.com/webhook' })
+    end
+  end
+
+  describe '#valid?' do
+    it 'returns true when events contains the wildcard event' do
+      raw = double(events: ['*', 'commit_comment'], active: true)
+      formatter = described_class.new(raw)
+      expect(formatter.valid?).to eq true
+    end
+
+    it 'returns true when events contains the create event' do
+      raw = double(events: ['create', 'commit_comment'], active: true)
+      formatter = described_class.new(raw)
+      expect(formatter.valid?).to eq true
+    end
+
+    it 'returns true when events contains delete event' do
+      raw = double(events: ['delete', 'commit_comment'], active: true)
+      formatter = described_class.new(raw)
+      expect(formatter.valid?).to eq true
+    end
+
+    it 'returns true when events contains pull_request event' do
+      raw = double(events: ['pull_request', 'commit_comment'], active: true)
+      formatter = described_class.new(raw)
+      expect(formatter.valid?).to eq true
+    end
+
+    it 'returns false when events does not contains branch related events' do
+      raw = double(events: ['member', 'commit_comment'], active: true)
+      formatter = described_class.new(raw)
+      expect(formatter.valid?).to eq false
+    end
+
+    it 'returns false when hook is not active' do
+      raw = double(events: ['pull_request', 'commit_comment'], active: false)
+      formatter = described_class.new(raw)
+      expect(formatter.valid?).to eq false
+    end
+  end
+end