Add snippet repository model

We need to create the repository model
for snippets. It will be the same for both
project and personal ones.

This commit also refactors some code in
order to reuse it in projects and snippets

app/models/commit.rb

@@ -244,6 +244,8 @@ class Commit
   # Discover issues should be closed when this commit is pushed to a project's
   # default branch.
   def closes_issues(current_user = self.committer)
+    return unless repository.repo_type.project?
+
     Gitlab::ClosingIssueExtractor.new(project, current_user).closed_by_message(safe_message)
   end
 
@@ -297,7 +299,11 @@ class Commit
   end
 
   def merge_requests
-    @merge_requests ||= project&.merge_requests&.by_commit_sha(sha)
+    strong_memoize(:merge_requests) do
+      next MergeRequest.none unless repository.repo_type.project? && project
+
+      project.merge_requests.by_commit_sha(sha)
+    end
   end
 
   def method_missing(method, *args, &block)
@@ -507,7 +513,7 @@ class Commit
   end
 
   def commit_reference(from, referable_commit_id, full: false)
-    base = project&.to_reference_base(from, full: full)
+    base = container.to_reference_base(from, full: full)
 
     if base.present?
       "#{base}#{self.class.reference_prefix}#{referable_commit_id}"

app/models/concerns/has_repository.rb

 # frozen_string_literal: true
 
+# This concern is created to handle repository actions.
+# It should be include inside any object capable
+# of directly having a repository, like project or snippet.
+#
+# It also includes `Referable`, therefore the method
+# `to_reference` should be overriden in case the object
+# needs any special behavior.
 module HasRepository
   extend ActiveSupport::Concern
   include Gitlab::ShellAdapter
   include AfterCommitQueue
+  include Referable
   include Gitlab::Utils::StrongMemoize
 
   delegate :base_dir, :disk_path, to: :storage

app/models/personal_snippet.rb

@@ -2,4 +2,8 @@
 
 class PersonalSnippet < Snippet
   include WithUploads
+
+  def web_url(only_path: nil)
+    Gitlab::Routing.url_helpers.snippet_url(self, only_path: only_path)
+  end
 end

app/models/project.rb

@@ -9,7 +9,6 @@ class Project < ApplicationRecord
   include AccessRequestable
   include Avatarable
   include CacheMarkdownField
-  include Referable
   include Sortable
   include AfterCommitQueue
   include CaseSensitivity

app/models/project_snippet.rb

@@ -5,4 +5,8 @@ class ProjectSnippet < Snippet
 
   validates :project, presence: true
   validates :secret, inclusion: { in: [false] }
+
+  def web_url(only_path: nil)
+    Gitlab::Routing.url_helpers.project_snippet_url(project, self, only_path: only_path)
+  end
 end

app/models/repository.rb

@@ -1143,8 +1143,12 @@ class Repository
   end
 
   def project
+    if repo_type.snippet?
+      container.project
+    else
       container
     end
+  end
 
   private
 
@@ -1157,7 +1161,7 @@ class Repository
                Gitlab::Git::Commit.find(raw_repository, oid_or_ref)
              end
 
-    ::Commit.new(commit, project) if commit
+    ::Commit.new(commit, container) if commit
   end
 
   def cache

app/models/snippet.rb

@@ -6,7 +6,6 @@ class Snippet < ApplicationRecord
   include CacheMarkdownField
   include Noteable
   include Participable
-  include Referable
   include Sortable
   include Awardable
   include Mentionable
@@ -15,10 +14,11 @@ class Snippet < ApplicationRecord
   include Gitlab::SQL::Pattern
   include FromUnion
   include IgnorableColumns
-
+  include HasRepository
   extend ::Gitlab::Utils::Override
 
   ignore_column :storage_version, remove_with: '12.9', remove_after: '2020-03-22'
+  ignore_column :repository_storage, remove_with: '12.10', remove_after: '2020-04-22'
 
   cache_markdown_field :title, pipeline: :single_line
   cache_markdown_field :description
@@ -42,6 +42,7 @@ class Snippet < ApplicationRecord
 
   has_many :notes, as: :noteable, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
   has_many :user_mentions, class_name: "SnippetUserMention"
+  has_one :snippet_repository, inverse_of: :snippet
 
   delegate :name, :email, to: :author, prefix: true, allow_nil: true
 
@@ -254,6 +255,47 @@ class Snippet < ApplicationRecord
     super
   end
 
+  def repository
+    @repository ||= Repository.new(full_path, self, disk_path: disk_path, repo_type: Gitlab::GlRepository::SNIPPET)
+  end
+
+  def storage
+    @storage ||= Storage::Hashed.new(self, prefix: Storage::Hashed::SNIPPET_REPOSITORY_PATH_PREFIX)
+  end
+
+  # This is the full_path used to identify the
+  # the snippet repository. It will be used mostly
+  # for logging purposes.
+  def full_path
+    return unless persisted?
+
+    @full_path ||= begin
+      components = []
+      components << project.full_path if project_id?
+      components << '@snippets'
+      components << self.id
+      components.join('/')
+    end
+  end
+
+  def repository_storage
+    snippet_repository&.shard_name ||
+      Gitlab::CurrentSettings.pick_repository_storage
+  end
+
+  def create_repository
+    return if repository_exists?
+
+    repository.create_if_not_exists
+
+    track_snippet_repository if repository_exists?
+  end
+
+  def track_snippet_repository
+    repository = snippet_repository || build_snippet_repository
+    repository.update!(shard_name: repository_storage, disk_path: disk_path)
+  end
+
   class << self
     # Searches for snippets with a matching title or file name.
     #

app/models/snippet_repository.rb

+# frozen_string_literal: true
+
+class SnippetRepository < ApplicationRecord
+  include Shardable
+
+  belongs_to :snippet, inverse_of: :snippet_repository
+
+  class << self
+    def find_snippet(disk_path)
+      find_by(disk_path: disk_path)&.snippet
+    end
+  end
+end

app/models/storage/hashed.rb

@@ -2,14 +2,15 @@
 
 module Storage
   class Hashed
-    attr_accessor :project
-    delegate :gitlab_shell, :repository_storage, to: :project
+    attr_accessor :container
+    delegate :gitlab_shell, :repository_storage, to: :container
 
     REPOSITORY_PATH_PREFIX = '@hashed'
+    SNIPPET_REPOSITORY_PATH_PREFIX = '@snippets'
     POOL_PATH_PREFIX = '@pools'
 
-    def initialize(project, prefix: REPOSITORY_PATH_PREFIX)
-      @project = project
+    def initialize(container, prefix: REPOSITORY_PATH_PREFIX)
+      @container = container
       @prefix = prefix
     end
 
@@ -20,9 +21,10 @@ module Storage
       "#{@prefix}/#{disk_hash[0..1]}/#{disk_hash[2..3]}" if disk_hash
     end
 
-    # Disk path is used to build repository and project's wiki path on disk
+    # Disk path is used to build repository path on disk
     #
-    # @return [String] combination of base_dir and the repository own name without `.git` or `.wiki.git` extensions
+    # @return [String] combination of base_dir and the repository own name
+    # without `.git`, `.wiki.git`, or any other extension
     def disk_path
       "#{base_dir}/#{disk_hash}" if disk_hash
     end
@@ -33,10 +35,10 @@ module Storage
 
     private
 
-    # Generates the hash for the project path and name on disk
+    # Generates the hash for the repository path and name on disk
     # If you need to refer to the repository on disk, use the `#disk_path`
     def disk_hash
-      @disk_hash ||= Digest::SHA2.hexdigest(project.id.to_s) if project.id
+      @disk_hash ||= Digest::SHA2.hexdigest(container.id.to_s) if container.id
     end
   end
 end

changelogs/unreleased/fj-create-snippet-repository-model.yml

+---
+title: Create snippet repository model
+merge_request: 23796
+author:
+type: added

db/migrate/20200206112850_create_snippet_repository_table.rb

+# frozen_string_literal: true
+
+class CreateSnippetRepositoryTable < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    create_table :snippet_repositories, id: false, primary_key: :snippet_id do |t|
+      t.references :shard, null: false, index: true, foreign_key: { on_delete: :restrict }
+      t.references :snippet, primary_key: true, default: nil, index: false, foreign_key: { on_delete: :cascade }
+      t.string :disk_path, limit: 80, null: false, index: { unique: true }
+    end
+  end
+end

db/schema.rb

@@ -3892,6 +3892,13 @@ ActiveRecord::Schema.define(version: 2020_02_11_152410) do
     t.index ["user_id"], name: "index_smartcard_identities_on_user_id"
   end
 
+  create_table "snippet_repositories", primary_key: "snippet_id", id: :bigint, default: nil, force: :cascade do |t|
+    t.bigint "shard_id", null: false
+    t.string "disk_path", limit: 80, null: false
+    t.index ["disk_path"], name: "index_snippet_repositories_on_disk_path", unique: true
+    t.index ["shard_id"], name: "index_snippet_repositories_on_shard_id"
+  end
+
   create_table "snippet_user_mentions", force: :cascade do |t|
     t.integer "snippet_id", null: false
     t.integer "note_id"
@@ -4963,6 +4970,8 @@ ActiveRecord::Schema.define(version: 2020_02_11_152410) do
   add_foreign_key "services", "projects", name: "fk_71cce407f9", on_delete: :cascade
   add_foreign_key "slack_integrations", "services", on_delete: :cascade
   add_foreign_key "smartcard_identities", "users", on_delete: :cascade
+  add_foreign_key "snippet_repositories", "shards", on_delete: :restrict
+  add_foreign_key "snippet_repositories", "snippets", on_delete: :cascade
   add_foreign_key "snippet_user_mentions", "notes", on_delete: :cascade
   add_foreign_key "snippet_user_mentions", "snippets", on_delete: :cascade
   add_foreign_key "snippets", "projects", name: "fk_be41fd4bb7", on_delete: :cascade

ee/spec/lib/gitlab/gl_repository/repo_type_spec.rb

@@ -17,6 +17,7 @@ describe Gitlab::GlRepository::RepoType do
       expect(described_class).to be_design
       expect(described_class).not_to be_project
       expect(described_class).not_to be_wiki
+      expect(described_class).not_to be_snippet
     end
 
     it 'checks if repository path is valid' do

lib/gitlab/git_access_snippet.rb

+# frozen_string_literal: true
+
+module Gitlab
+  class GitAccessSnippet < GitAccess
+    ERROR_MESSAGES = {
+      snippet_not_found: 'The snippet you were looking for could not be found.',
+      repository_not_found: 'The snippet repository you were looking for could not be found.'
+    }.freeze
+
+    attr_reader :snippet
+
+    def initialize(actor, snippet, protocol, **kwargs)
+      @snippet = snippet
+
+      super(actor, project, protocol, **kwargs)
+    end
+
+    def check(cmd, _changes)
+      unless Feature.enabled?(:version_snippets, user)
+        raise NotFoundError, ERROR_MESSAGES[:snippet_not_found]
+      end
+
+      check_snippet_accessibility!
+
+      success_result(cmd)
+    end
+
+    def project
+      snippet&.project
+    end
+
+    private
+
+    def repository
+      snippet&.repository
+    end
+
+    def check_snippet_accessibility!
+      if snippet.blank?
+        raise NotFoundError, ERROR_MESSAGES[:snippet_not_found]
+      end
+
+      unless repository&.exists?
+        raise NotFoundError, ERROR_MESSAGES[:repository_not_found]
+      end
+    end
+  end
+end

lib/gitlab/gl_repository.rb

@@ -15,10 +15,17 @@ module Gitlab
       repository_resolver: -> (project) { project.wiki.repository },
       suffix: :wiki
     ).freeze
+    SNIPPET = RepoType.new(
+      name: :snippet,
+      access_checker_class: Gitlab::GitAccessSnippet,
+      repository_resolver: -> (snippet) { snippet.repository },
+      container_resolver: -> (id) { Snippet.find_by_id(id) }
+    ).freeze
 
     TYPES = {
       PROJECT.name.to_s => PROJECT,
-      WIKI.name.to_s => WIKI
+      WIKI.name.to_s => WIKI,
+      SNIPPET.name.to_s => SNIPPET
     }.freeze
 
     def self.types

lib/gitlab/gl_repository/repo_type.rb

@@ -47,6 +47,10 @@ module Gitlab
         self == PROJECT
       end
 
+      def snippet?
+        self == SNIPPET
+      end
+
       def path_suffix
         suffix ? ".#{suffix}" : ''
       end

spec/factories/snippet_repositories.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :snippet_repository do
+    snippet
+
+    after(:build) do |snippet_repository, _|
+      snippet_repository.shard_name = snippet_repository.snippet.repository_storage
+      snippet_repository.disk_path  = snippet_repository.snippet.disk_path
+    end
+  end
+end

spec/factories/snippets.rb

@@ -20,6 +20,21 @@ FactoryBot.define do
     trait :private do
       visibility_level { Snippet::PRIVATE }
     end
+
+    # Test repository - https://gitlab.com/gitlab-org/gitlab-test
+    trait :repository do
+      after :create do |snippet|
+        TestEnv.copy_repo(snippet,
+          bare_repo: TestEnv.factory_repo_path_bare,
+          refs: TestEnv::BRANCH_SHA)
+      end
+    end
+
+    trait :empty_repo do
+      after(:create) do |snippet|
+        raise "Failed to create repository!" unless snippet.repository.create_if_not_exists
+      end
+    end
   end
 
   factory :project_snippet, parent: :snippet, class: :ProjectSnippet do

spec/lib/gitlab/git_access_snippet_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::GitAccessSnippet do
+  include GitHelpers
+
+  let_it_be(:user) { create(:user) }
+  let_it_be(:personal_snippet) { create(:personal_snippet, :private, :repository) }
+
+  let(:protocol) { 'ssh' }
+  let(:changes) { Gitlab::GitAccess::ANY }
+  let(:push_access_check) { access.check('git-receive-pack', changes) }
+  let(:pull_access_check) { access.check('git-upload-pack', changes) }
+  let(:snippet) { personal_snippet }
+  let(:actor) { personal_snippet.author }
+
+  describe 'when feature flag :version_snippets is enabled' do
+    it 'allows push and pull access' do
+      aggregate_failures do
+        expect { pull_access_check }.not_to raise_error
+        expect { push_access_check }.not_to raise_error
+      end
+    end
+  end
+
+  describe 'when feature flag :version_snippets is disabled' do
+    before do
+      stub_feature_flags(version_snippets: false)
+    end
+
+    it 'does not allow push and pull access' do
+      aggregate_failures do
+        expect { push_access_check }.to raise_snippet_not_found
+        expect { pull_access_check }.to raise_snippet_not_found
+      end
+    end
+  end
+
+  describe '#check_snippet_accessibility!' do
+    context 'when the snippet exists' do
+      it 'allows push and pull access' do
+        aggregate_failures do
+          expect { pull_access_check }.not_to raise_error
+          expect { push_access_check }.not_to raise_error
+        end
+      end
+    end
+
+    context 'when the snippet is nil' do
+      let(:snippet) { nil }
+
+      it 'blocks push and pull with "not found"' do
+        aggregate_failures do
+          expect { pull_access_check }.to raise_snippet_not_found
+          expect { push_access_check }.to raise_snippet_not_found
+        end
+      end
+    end
+
+    context 'when the snippet does not have a repository' do
+      let(:snippet) { build_stubbed(:personal_snippet) }
+
+      it 'blocks push and pull with "not found"' do
+        aggregate_failures do
+          expect { pull_access_check }.to raise_snippet_not_found
+          expect { push_access_check }.to raise_snippet_not_found
+        end
+      end
+    end
+  end
+
+  private
+
+  def access
+    described_class.new(actor, snippet, protocol,
+                        authentication_abilities: [],
+                        namespace_path: nil, project_path: nil,
+                        redirected_path: nil, auth_result_type: nil)
+  end
+
+  def raise_snippet_not_found
+    raise_error(Gitlab::GitAccess::NotFoundError, Gitlab::GitAccess::ERROR_MESSAGES[:snippet_not_found])
+  end
+end

spec/lib/gitlab/gl_repository/repo_type_spec.rb

@@ -3,6 +3,8 @@ require 'spec_helper'
 
 describe Gitlab::GlRepository::RepoType do
   let_it_be(:project) { create(:project) }
+  let_it_be(:personal_snippet) { create(:personal_snippet, author: project.owner) }
+  let_it_be(:project_snippet) { create(:project_snippet, project: project, author: project.owner) }
 
   describe Gitlab::GlRepository::PROJECT do
     it_behaves_like 'a repo type' do
@@ -16,6 +18,7 @@ describe Gitlab::GlRepository::RepoType do
     it 'knows its type' do
       expect(described_class).not_to be_wiki
       expect(described_class).to be_project
+      expect(described_class).not_to be_snippet
     end
 
     it 'checks if repository path is valid' do
@@ -36,6 +39,7 @@ describe Gitlab::GlRepository::RepoType do
     it 'knows its type' do
       expect(described_class).to be_wiki
       expect(described_class).not_to be_project
+      expect(described_class).not_to be_snippet
     end
 
     it 'checks if repository path is valid' do
@@ -43,4 +47,38 @@ describe Gitlab::GlRepository::RepoType do
       expect(described_class.valid?(project.wiki.repository.full_path)).to be_truthy
     end
   end
+
+  describe Gitlab::GlRepository::SNIPPET do
+    context 'when PersonalSnippet' do
+      it_behaves_like 'a repo type' do
+        let(:expected_id) { personal_snippet.id.to_s }
+        let(:expected_identifier) { "snippet-#{expected_id}" }
+        let(:expected_suffix) { '' }
+        let(:expected_repository) { personal_snippet.repository }
+        let(:expected_container) { personal_snippet }
+      end
+
+      it 'knows its type' do
+        expect(described_class).to be_snippet
+        expect(described_class).not_to be_wiki
+        expect(described_class).not_to be_project
+      end
+    end
+
+    context 'when ProjectSnippet' do
+      it_behaves_like 'a repo type' do
+        let(:expected_id) { project_snippet.id.to_s }
+        let(:expected_identifier) { "snippet-#{expected_id}" }
+        let(:expected_suffix) { '' }
+        let(:expected_repository) { project_snippet.repository }
+        let(:expected_container) { project_snippet }
+      end
+
+      it 'knows its type' do
+        expect(described_class).to be_snippet
+        expect(described_class).not_to be_wiki
+        expect(described_class).not_to be_project
+      end
+    end
+  end
 end

spec/lib/gitlab/import_export/all_models.yml

@@ -91,6 +91,7 @@ snippets:
 - award_emoji
 - user_agent_detail
 - user_mentions
+- snippet_repository
 releases:
 - author
 - project

spec/models/commit_spec.rb

@@ -3,7 +3,9 @@
 require 'spec_helper'
 
 describe Commit do
-  let(:project) { create(:project, :public, :repository) }
+  let_it_be(:project) { create(:project, :public, :repository) }
+  let_it_be(:personal_snippet) { create(:personal_snippet, :repository) }
+  let_it_be(:project_snippet) { create(:project_snippet, :repository) }
   let(:commit) { project.commit }
 
   describe 'modules' do
@@ -17,8 +19,7 @@ describe Commit do
   end
 
   describe '.lazy' do
-    let_it_be(:project) { create(:project, :repository) }
-
+    shared_examples '.lazy checks' do
       context 'when the commits are found' do
         let(:oids) do
           %w(
@@ -30,10 +31,10 @@ describe Commit do
           )
         end
 
-      subject { oids.map { |oid| described_class.lazy(project, oid) } }
+        subject { oids.map { |oid| described_class.lazy(container, oid) } }
 
         it 'batches requests for commits' do
-        expect(project.repository).to receive(:commits_by).once.and_call_original
+          expect(container.repository).to receive(:commits_by).once.and_call_original
 
           subject.first.title
           subject.last.title
@@ -56,13 +57,32 @@ describe Commit do
 
       context 'when not found' do
         it 'returns nil as commit' do
-        commit = described_class.lazy(project, 'deadbeef').__sync
+          commit = described_class.lazy(container, 'deadbeef').__sync
 
           expect(commit).to be_nil
         end
       end
     end
 
+    context 'with project' do
+      let(:container) { project }
+
+      it_behaves_like '.lazy checks'
+    end
+
+    context 'with personal snippet' do
+      let(:container) { personal_snippet }
+
+      it_behaves_like '.lazy checks'
+    end
+
+    context 'with project snippet' do
+      let(:container) { project_snippet }
+
+      it_behaves_like '.lazy checks'
+    end
+  end
+
   describe '#diff_refs' do
     it 'is equal to itself' do
       expect(commit.diff_refs).to eq(commit.diff_refs)
@@ -231,6 +251,7 @@ describe Commit do
   end
 
   describe '#to_reference' do
+    context 'with project' do
       let(:project) { create(:project, :repository, path: 'sample-project') }
 
       it 'returns a String reference to the object' do
@@ -243,6 +264,33 @@ describe Commit do
       end
     end
 
+    context 'with personal snippet' do
+      let(:commit) { personal_snippet.commit }
+
+      it 'returns a String reference to the object' do
+        expect(commit.to_reference).to eq "$#{personal_snippet.id}@#{commit.id}"
+      end
+
+      it 'supports a cross-snippet reference' do
+        another_snippet = build(:personal_snippet)
+        expect(commit.to_reference(another_snippet)).to eq "$#{personal_snippet.id}@#{commit.id}"
+      end
+    end
+
+    context 'with project snippet' do
+      let(:commit) { project_snippet.commit }
+
+      it 'returns a String reference to the object' do
+        expect(commit.to_reference).to eq "$#{project_snippet.id}@#{commit.id}"
+      end
+
+      it 'supports a cross-snippet project reference' do
+        another_snippet = build(:personal_snippet)
+        expect(commit.to_reference(another_snippet)).to eq "#{project_snippet.project.path}$#{project_snippet.id}@#{commit.id}"
+      end
+    end
+  end
+
   describe '.reference_valid?' do
     using RSpec::Parameterized::TableSyntax
 
@@ -264,6 +312,7 @@ describe Commit do
   describe '#reference_link_text' do
     let(:project) { create(:project, :repository, path: 'sample-project') }
 
+    context 'with project' do
       it 'returns a String reference to the object' do
         expect(commit.reference_link_text).to eq commit.short_id
       end
@@ -274,6 +323,33 @@ describe Commit do
       end
     end
 
+    context 'with personal snippet' do
+      let(:commit) { personal_snippet.commit }
+
+      it 'returns a String reference to the object' do
+        expect(commit.reference_link_text).to eq "$#{personal_snippet.id}@#{commit.short_id}"
+      end
+
+      it 'supports a cross-snippet reference' do
+        another_snippet = build(:personal_snippet, :repository)
+        expect(commit.reference_link_text(another_snippet)).to eq "$#{personal_snippet.id}@#{commit.short_id}"
+      end
+    end
+
+    context 'with project snippet' do
+      let(:commit) { project_snippet.commit }
+
+      it 'returns a String reference to the object' do
+        expect(commit.reference_link_text).to eq "$#{project_snippet.id}@#{commit.short_id}"
+      end
+
+      it 'supports a cross-snippet project reference' do
+        another_snippet = build(:project_snippet, :repository)
+        expect(commit.reference_link_text(another_snippet)).to eq "#{project_snippet.project.path}$#{project_snippet.id}@#{commit.short_id}"
+      end
+    end
+  end
+
   describe '#title' do
     it "returns no_commit_message when safe_message is blank" do
       allow(commit).to receive(:safe_message).and_return('')
@@ -401,6 +477,26 @@ eos
 
       expect(commit.closes_issues).to be_empty
     end
+
+    context 'with personal snippet' do
+      let(:commit) { personal_snippet.commit }
+
+      it 'does not call Gitlab::ClosingIssueExtractor' do
+        expect(Gitlab::ClosingIssueExtractor).not_to receive(:new)
+
+        commit.closes_issues
+      end
+    end
+
+    context 'with project snippet' do
+      let(:commit) { project_snippet.commit }
+
+      it 'does not call Gitlab::ClosingIssueExtractor' do
+        expect(Gitlab::ClosingIssueExtractor).not_to receive(:new)
+
+        commit.closes_issues
+      end
+    end
   end
 
   it_behaves_like 'a mentionable' do
@@ -597,19 +693,39 @@ eos
   end
 
   describe '.from_hash' do
-    let(:new_commit) { described_class.from_hash(commit.to_hash, project) }
+    subject { described_class.from_hash(commit.to_hash, container) }
 
+    shared_examples 'returns Commit' do
       it 'returns a Commit' do
-      expect(new_commit).to be_an_instance_of(described_class)
+        expect(subject).to be_an_instance_of(described_class)
       end
 
       it 'wraps a Gitlab::Git::Commit' do
-      expect(new_commit.raw).to be_an_instance_of(Gitlab::Git::Commit)
+        expect(subject.raw).to be_an_instance_of(Gitlab::Git::Commit)
       end
 
       it 'stores the correct commit fields' do
-      expect(new_commit.id).to eq(commit.id)
-      expect(new_commit.message).to eq(commit.message)
+        expect(subject.id).to eq(commit.id)
+        expect(subject.message).to eq(commit.message)
+      end
+    end
+
+    context 'with project' do
+      let(:container) { project }
+
+      it_behaves_like 'returns Commit'
+    end
+
+    context 'with personal snippet' do
+      let(:container) { personal_snippet }
+
+      it_behaves_like 'returns Commit'
+    end
+
+    context 'with project snippet' do
+      let(:container) { project_snippet }
+
+      it_behaves_like 'returns Commit'
     end
   end
 
@@ -670,6 +786,19 @@ eos
       expect(commit1.merge_requests).to contain_exactly(merge_request1, merge_request2)
       expect(commit2.merge_requests).to contain_exactly(merge_request1)
     end
+
+    context 'with personal snippet' do
+      it 'returns empty relation' do
+        expect(personal_snippet.repository.commit.merge_requests).to eq MergeRequest.none
+      end
+    end
+
+    context 'with project snippet' do
+      it 'returns empty relation' do
+        expect(project_snippet.project).not_to receive(:merge_requests)
+        expect(project_snippet.repository.commit.merge_requests).to eq MergeRequest.none
+      end
+    end
   end
 
   describe 'signed commits' do

spec/models/personal_snippet_spec.rb

@@ -16,4 +16,13 @@ describe PersonalSnippet do
       end
     end
   end
+
+  it_behaves_like 'model with repository' do
+    let_it_be(:container) { create(:personal_snippet, :repository) }
+    let(:stubbed_container) { build_stubbed(:personal_snippet) }
+    let(:expected_full_path) { "@snippets/#{container.id}" }
+    let(:expected_repository_klass) { Repository }
+    let(:expected_storage_klass) { Storage::Hashed }
+    let(:expected_web_url_path) { "snippets/#{container.id}" }
+  end
 end

spec/models/project_snippet_spec.rb

@@ -32,4 +32,13 @@ describe ProjectSnippet do
       end
     end
   end
+
+  it_behaves_like 'model with repository' do
+    let_it_be(:container) { create(:project_snippet, :repository) }
+    let(:stubbed_container) { build_stubbed(:project_snippet) }
+    let(:expected_full_path) { "#{container.project.full_path}/@snippets/#{container.id}" }
+    let(:expected_repository_klass) { Repository }
+    let(:expected_storage_klass) { Storage::Hashed }
+    let(:expected_web_url_path) { "#{container.project.full_path}/snippets/#{container.id}" }
+  end
 end

spec/models/project_spec.rb

@@ -113,6 +113,7 @@ describe Project do
       let(:expected_full_path) { "#{container.namespace.full_path}/somewhere" }
       let(:expected_repository_klass) { Repository }
       let(:expected_storage_klass) { Storage::Hashed }
+      let(:expected_web_url_path) { "#{container.namespace.full_path}/somewhere" }
     end
 
     it 'has an inverse relationship with merge requests' do

spec/models/snippet_repository_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe SnippetRepository do
+  describe 'associations' do
+    it { is_expected.to belong_to(:shard) }
+    it { is_expected.to belong_to(:snippet) }
+  end
+
+  describe '.find_snippet' do
+    it 'finds snippet by disk path' do
+      snippet = create(:snippet)
+      snippet.track_snippet_repository
+
+      expect(described_class.find_snippet(snippet.disk_path)).to eq(snippet)
+    end
+
+    it 'returns nil when it does not find the snippet' do
+      expect(described_class.find_snippet('@@unexisting/path/to/snippet')).to be_nil
+    end
+  end
+end

spec/models/snippet_spec.rb

@@ -19,6 +19,7 @@ describe Snippet do
     it { is_expected.to have_many(:notes).dependent(:destroy) }
     it { is_expected.to have_many(:award_emoji).dependent(:destroy) }
     it { is_expected.to have_many(:user_mentions).class_name("SnippetUserMention") }
+    it { is_expected.to have_one(:snippet_repository) }
   end
 
   describe 'validation' do
@@ -525,4 +526,109 @@ describe Snippet do
       snippet.to_json(params)
     end
   end
+
+  describe '#storage' do
+    let(:snippet) { create(:snippet) }
+
+    it "stores snippet in #{Storage::Hashed::SNIPPET_REPOSITORY_PATH_PREFIX} dir" do
+      expect(snippet.storage.disk_path).to start_with Storage::Hashed::SNIPPET_REPOSITORY_PATH_PREFIX
+    end
+  end
+
+  describe '#track_snippet_repository' do
+    let(:snippet) { create(:snippet, :repository) }
+
+    context 'when a snippet repository entry does not exist' do
+      it 'creates a new entry' do
+        expect { snippet.track_snippet_repository }.to change(snippet, :snippet_repository)
+      end
+
+      it 'tracks the snippet storage location' do
+        snippet.track_snippet_repository
+
+        expect(snippet.snippet_repository).to have_attributes(
+          disk_path: snippet.disk_path,
+          shard_name: snippet.repository_storage
+        )
+      end
+    end
+
+    context 'when a tracking entry exists' do
+      let!(:snippet_repository) { create(:snippet_repository, snippet: snippet) }
+      let!(:shard) { create(:shard, name: 'foo') }
+
+      it 'does not create a new entry in the database' do
+        expect { snippet.track_snippet_repository }.not_to change(snippet, :snippet_repository)
+      end
+
+      it 'updates the snippet storage location' do
+        allow(snippet).to receive(:disk_path).and_return('fancy/new/path')
+        allow(snippet).to receive(:repository_storage).and_return('foo')
+
+        snippet.track_snippet_repository
+
+        expect(snippet.snippet_repository).to have_attributes(
+          disk_path: 'fancy/new/path',
+          shard_name: 'foo'
+        )
+      end
+    end
+  end
+
+  describe '#create_repository' do
+    let(:snippet) { create(:snippet) }
+
+    it 'creates the repository' do
+      expect(snippet.repository).to receive(:after_create).and_call_original
+
+      expect(snippet.create_repository).to be_truthy
+      expect(snippet.repository.exists?).to be_truthy
+    end
+
+    it 'tracks snippet repository' do
+      expect do
+        snippet.create_repository
+      end.to change(SnippetRepository, :count).by(1)
+    end
+
+    context 'when repository exists' do
+      let(:snippet) { create(:snippet, :repository) }
+
+      it 'does not try to create repository' do
+        expect(snippet.repository).not_to receive(:after_create)
+
+        expect(snippet.create_repository).to be_nil
+      end
+
+      it 'does not track snippet repository' do
+        expect do
+          snippet.create_repository
+        end.not_to change(SnippetRepository, :count)
+      end
+    end
+  end
+
+  describe '#repository_storage' do
+    let(:snippet) { create(:snippet) }
+
+    it 'returns default repository storage' do
+      expect(Gitlab::CurrentSettings).to receive(:pick_repository_storage)
+
+      snippet.repository_storage
+    end
+
+    context 'when snippet_project is already created' do
+      let!(:snippet_repository) { create(:snippet_repository, snippet: snippet) }
+
+      before do
+        allow(snippet_repository).to receive(:shard_name).and_return('foo')
+      end
+
+      it 'returns repository_storage from snippet_project' do
+        expect(Gitlab::CurrentSettings).not_to receive(:pick_repository_storage)
+
+        expect(snippet.repository_storage).to eq 'foo'
+      end
+    end
+  end
 end

spec/support/helpers/fake_blob_helpers.rb

@@ -37,6 +37,8 @@ module FakeBlobHelpers
   end
 
   def fake_blob(**kwargs)
-    Blob.decorate(FakeBlob.new(**kwargs), project)
+    container = kwargs.delete(:container) || project
+
+    Blob.decorate(FakeBlob.new(**kwargs), container)
   end
 end

spec/support/shared_examples/lib/gitlab/repo_type_shared_examples.rb

@@ -2,7 +2,7 @@
 
 RSpec.shared_examples 'a repo type' do
   describe '#identifier_for_container' do
-    subject { described_class.identifier_for_container(project) }
+    subject { described_class.identifier_for_container(expected_container) }
 
     it { is_expected.to eq(expected_identifier) }
   end
@@ -35,7 +35,7 @@ RSpec.shared_examples 'a repo type' do
 
   describe '#repository_for' do
     it 'finds the repository for the repo type' do
-      expect(described_class.repository_for(project)).to eq(expected_repository)
+      expect(described_class.repository_for(expected_container)).to eq(expected_repository)
     end
   end
 end

spec/support/shared_examples/models/concerns/has_repository_shared_examples.rb

@@ -18,7 +18,7 @@ RSpec.shared_examples 'model with repository' do
         let(:only_path) { false }
 
         it 'returns the full web URL for this repo' do
-          expect(subject).to eq("#{Gitlab.config.gitlab.url}/#{expected_full_path}")
+          expect(subject).to eq("#{Gitlab.config.gitlab.url}/#{expected_web_url_path}")
         end
       end
 
@@ -26,7 +26,7 @@ RSpec.shared_examples 'model with repository' do
         let(:only_path) { true }
 
         it 'returns the relative web URL for this repo' do
-          expect(subject).to eq("/#{expected_full_path}")
+          expect(subject).to eq("/#{expected_web_url_path}")
         end
       end
 
@@ -34,14 +34,14 @@ RSpec.shared_examples 'model with repository' do
         let(:only_path) { nil }
 
         it 'returns the full web URL for this repo' do
-          expect(subject).to eq("#{Gitlab.config.gitlab.url}/#{expected_full_path}")
+          expect(subject).to eq("#{Gitlab.config.gitlab.url}/#{expected_web_url_path}")
         end
       end
     end
 
     context 'when not given the only_path option' do
       it 'returns the full web URL for this repo' do
-        expect(container.web_url).to eq("#{Gitlab.config.gitlab.url}/#{expected_full_path}")
+        expect(container.web_url).to eq("#{Gitlab.config.gitlab.url}/#{expected_web_url_path}")
       end
     end
   end
@@ -72,7 +72,7 @@ RSpec.shared_examples 'model with repository' do
           let(:custom_http_clone_url_root) { 'https://git.example.com:51234/mygitlab/' }
 
           it 'returns the url to the repo, with the root replaced with the custom one' do
-            expect(subject).to eq("#{custom_http_clone_url_root}#{expected_full_path}.git")
+            expect(subject).to eq("#{custom_http_clone_url_root}#{expected_web_url_path}.git")
           end
         end
 
@@ -80,7 +80,7 @@ RSpec.shared_examples 'model with repository' do
           let(:custom_http_clone_url_root) { 'https://git.example.com:51234/mygitlab' }
 
           it 'returns the url to the repo, with the root replaced with the custom one' do
-            expect(subject).to eq("#{custom_http_clone_url_root}/#{expected_full_path}.git")
+            expect(subject).to eq("#{custom_http_clone_url_root}/#{expected_web_url_path}.git")
           end
         end
       end
@@ -90,7 +90,7 @@ RSpec.shared_examples 'model with repository' do
           let(:custom_http_clone_url_root) { 'https://git.example.com:51234/' }
 
           it 'returns the url to the repo, with the root replaced with the custom one' do
-            expect(subject).to eq("#{custom_http_clone_url_root}#{expected_full_path}.git")
+            expect(subject).to eq("#{custom_http_clone_url_root}#{expected_web_url_path}.git")
           end
         end
 
@@ -98,7 +98,7 @@ RSpec.shared_examples 'model with repository' do
           let(:custom_http_clone_url_root) { 'https://git.example.com:51234' }
 
           it 'returns the url to the repo, with the root replaced with the custom one' do
-            expect(subject).to eq("#{custom_http_clone_url_root}/#{expected_full_path}.git")
+            expect(subject).to eq("#{custom_http_clone_url_root}/#{expected_web_url_path}.git")
           end
         end
       end