Implement container repository path class

lib/container_registry/path.rb

+module ContainerRegistry
+  class Path
+    InvalidRegistryPathError = Class.new(StandardError)
+
+    def initialize(name)
+      @nodes = name.to_s.split('/')
+    end
+
+    def valid?
+      @nodes.size > 1 &&
+      @nodes.size < Namespace::NUMBER_OF_ANCESTORS_ALLOWED
+    end
+
+    def components
+      raise InvalidRegistryPathError unless valid?
+
+      @components ||= @nodes.size.downto(2).map do |length|
+        @nodes.take(length).join('/')
+      end
+    end
+
+    def repository_project
+      @project ||= Project.where_full_path_in(components.first(3))&.first
+    end
+
+    def repository_name
+    end
+  end
+end

spec/lib/container_registry/path_spec.rb

+require 'spec_helper'
+
+describe ContainerRegistry::Path do
+  let(:path) { described_class.new(name) }
+
+  describe '#components' do
+    context 'when repository path is valid' do
+      let(:name) { 'path/to/some/project' }
+
+      it 'return all project-like components in reverse order' do
+        expect(path.components).to eq %w[path/to/some/project
+                                         path/to/some
+                                         path/to]
+      end
+    end
+
+    context 'when repository path is invalid' do
+      let(:name) { '' }
+
+      it 'rasises en error' do
+        expect { path.components }
+          .to raise_error described_class::InvalidRegistryPathError
+      end
+    end
+  end
+
+  describe '#valid?' do
+    context 'when path has less than two components' do
+      let(:name) { 'something/' }
+
+      it 'is not valid' do
+        expect(path).not_to be_valid
+      end
+    end
+
+    context 'when path has more than allowed number of components' do
+      let(:name) { 'a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/r/s/t/u/w/y/z' }
+
+      it 'is not valid' do
+        expect(path).not_to be_valid
+      end
+    end
+
+    context 'when path has two or more components' do
+      let(:name) { 'some/path' }
+
+      it 'is valid' do
+        expect(path).to be_valid
+      end
+    end
+  end
+
+  describe '#repository_project' do
+    let(:group) { create(:group, path: 'some_group') }
+
+    context 'when project for given path exists' do
+      let(:name) { 'some_group/some_project' }
+
+      before do
+        create(:empty_project, group: group, name: 'some_project')
+        create(:empty_project, name: 'some_project')
+      end
+
+      it 'returns a correct project' do
+        expect(path.repository_project.group).to eq group
+      end
+    end
+
+    context 'when project for given path does not exist' do
+      let(:name) { 'not/matching' }
+
+      it 'returns nil' do
+        expect(path.repository_project).to be_nil
+      end
+    end
+
+    context 'when matching multi-level path' do
+      let(:project) do
+        create(:empty_project, group: group, name: 'some_project')
+      end
+
+      context 'when using the zero-level path' do
+        let(:name) { project.full_path }
+
+        it 'supports zero-level path' do
+          expect(path.repository_project).to eq project
+        end
+      end
+
+      context 'when using first-level path' do
+        let(:name) { "#{project.full_path}/repository" }
+
+        it 'supports first-level path' do
+          expect(path.repository_project).to eq project
+        end
+      end
+
+      context 'when using second-level path' do
+        let(:name) { "#{project.full_path}/repository/name" }
+
+        it 'supports second-level path' do
+          expect(path.repository_project).to eq project
+        end
+      end
+
+      context 'when using too deep nesting in the path' do
+        let(:name) { "#{project.full_path}/repository/name/invalid" }
+
+        it 'does not support three-levels of nesting' do
+          expect(path.repository_project).to be_nil
+        end
+      end
+    end
+  end
+
+  describe '#repository_name' do
+    pending 'returns a correct name'
+  end
+end