Normalize import_export structure

This brings a significant refactor to how
we handle `import_export.yml`, merge it with EE
and how we handle that for reader and saver.

This is meant to simplify the code, and remove
a ton of conditions to handle different models
of the structure.

This is also meant to prepare the structure
to extend it much easier, like adding `preload:`
or additional object types when needed.

This does not change the behavior of import/export,
rather unifies and simplifies the current implementation.

1 files changed, 195 insertions, 0 deletions

diff --git a/spec/lib/gitlab/import_export/attributes_finder_spec.rb b/spec/lib/gitlab/import_export/attributes_finder_spec.rb
new file mode 100644
index 00000000000..208b60844e3
--- /dev/null
+++ b/spec/lib/gitlab/import_export/attributes_finder_spec.rb
@@ -0,0 +1,195 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+describe Gitlab::ImportExport::AttributesFinder do
+  describe '#find_root' do
+    subject { described_class.new(config: config).find_root(model_key) }
+
+    let(:test_config) { 'spec/support/import_export/import_export.yml' }
+    let(:config) { Gitlab::ImportExport::Config.new.to_h }
+    let(:model_key) { :project }
+
+    let(:project_tree_hash) do
+      {
+        except: [:id, :created_at],
+        include: [
+          { issues: { include: [] } },
+          { labels: { include: [] } },
+          { merge_requests: {
+            except: [:iid],
+            include: [
+              { merge_request_diff: {
+                include: []
+              } },
+              { merge_request_test: { include: [] } }
+            ],
+            only: [:id]
+            } },
+          { commit_statuses: {
+              include: [{ commit: { include: [] } }]
+            } },
+          { project_members: {
+              include: [{ user: { include: [],
+                                  only: [:email] } }]
+          } }
+        ]
+      }
+    end
+
+    before do
+      allow_any_instance_of(Gitlab::ImportExport).to receive(:config_file).and_return(test_config)
+    end
+
+    it 'generates hash from project tree config' do
+      is_expected.to match(project_tree_hash)
+    end
+
+    context 'individual scenarios' do
+      it 'generates the correct hash for a single project relation' do
+        setup_yaml(tree: { project: [:issues] })
+
+        is_expected.to match(
+          include: [{ issues: { include: [] } }]
+        )
+      end
+
+      it 'generates the correct hash for a single project feature relation' do
+        setup_yaml(tree: { project: [:project_feature] })
+
+        is_expected.to match(
+          include: [{ project_feature: { include: [] } }]
+        )
+      end
+
+      it 'generates the correct hash for a multiple project relation' do
+        setup_yaml(tree: { project: [:issues, :snippets] })
+
+        is_expected.to match(
+          include: [{ issues: { include: [] } },
+                    { snippets: { include: [] } }]
+        )
+      end
+
+      it 'generates the correct hash for a single sub-relation' do
+        setup_yaml(tree: { project: [issues: [:notes]] })
+
+        is_expected.to match(
+          include: [{ issues: { include: [{ notes: { include: [] } }] } }]
+        )
+      end
+
+      it 'generates the correct hash for a multiple sub-relation' do
+        setup_yaml(tree: { project: [merge_requests: [:notes, :merge_request_diff]] })
+
+        is_expected.to match(
+          include: [{ merge_requests:
+                      { include: [{ notes: { include: [] } },
+                                  { merge_request_diff: { include: [] } }] } }]
+        )
+      end
+
+      it 'generates the correct hash for a sub-relation with another sub-relation' do
+        setup_yaml(tree: { project: [merge_requests: [notes: [:author]]] })
+
+        is_expected.to match(
+          include: [{ merge_requests: {
+                      include: [{ notes: { include: [{ author: { include: [] } }] } }]
+                    } }]
+        )
+      end
+
+      it 'generates the correct hash for a relation with included attributes' do
+        setup_yaml(tree: { project: [:issues] },
+                  included_attributes: { issues: [:name, :description] })
+
+        is_expected.to match(
+          include: [{ issues: { include: [],
+                                only: [:name, :description] } }]
+        )
+      end
+
+      it 'generates the correct hash for a relation with excluded attributes' do
+        setup_yaml(tree: { project: [:issues] },
+                  excluded_attributes: { issues: [:name] })
+
+        is_expected.to match(
+          include: [{ issues: { except: [:name],
+                                include: [] } }]
+        )
+      end
+
+      it 'generates the correct hash for a relation with both excluded and included attributes' do
+        setup_yaml(tree: { project: [:issues] },
+                  excluded_attributes: { issues: [:name] },
+                  included_attributes: { issues: [:description] })
+
+        is_expected.to match(
+          include: [{ issues: { except: [:name],
+                                include: [],
+                                only: [:description] } }]
+        )
+      end
+
+      it 'generates the correct hash for a relation with custom methods' do
+        setup_yaml(tree: { project: [:issues] },
+                  methods: { issues: [:name] })
+
+        is_expected.to match(
+          include: [{ issues: { include: [],
+                                methods: [:name] } }]
+        )
+      end
+
+      def setup_yaml(hash)
+        allow(YAML).to receive(:load_file).with(test_config).and_return(hash)
+      end
+    end
+  end
+
+  describe '#find_relations_tree' do
+    subject { described_class.new(config: config).find_relations_tree(model_key) }
+
+    let(:tree) { { project: { issues: {} } } }
+    let(:model_key) { :project }
+
+    context 'when initialized with config including tree' do
+      let(:config) { { tree: tree } }
+
+      context 'when relation is in top-level keys of the tree' do
+        it { is_expected.to eq({ issues: {} }) }
+      end
+
+      context 'when the relation is not in top-level keys' do
+        let(:model_key) { :issues }
+
+        it { is_expected.to be_nil }
+      end
+    end
+
+    context 'when tree is not present in config' do
+      let(:config) { {} }
+
+      it { is_expected.to be_nil }
+    end
+  end
+
+  describe '#find_excluded_keys' do
+    subject { described_class.new(config: config).find_excluded_keys(klass_name) }
+
+    let(:klass_name) { 'project' }
+
+    context 'when initialized with excluded_attributes' do
+      let(:config) { { excluded_attributes: excluded_attributes } }
+      let(:excluded_attributes) { { project: [:name, :path], issues: [:milestone_id] } }
+
+      it { is_expected.to eq(%w[name path]) }
+    end
+
+    context 'when excluded_attributes are not present in config' do
+      let(:config) { {} }
+
+      it { is_expected.to eq([]) }
+    end
+  end
+end