Add more attributes to the blob GraphQL API

`ide_edit_path`, `can_modify_blob`, `fork_and_edit_path` and
`ide_fork_and_edit_path` all have implementations in `BlobHelper`,
which are difficult to extract out. For now, just include the required
helpers to get access to the code.

In the future, we should be able to delete the existing FE for viewing
the repository, and at that point we should also be able to move this
code from BlobHelper and into BlobPresenter more easily.

`external_storage_url` has its implementation in `ApplicationHelper`.
Long term, moving this seems less likely. It probably fits better in a
URL generation location like `GitlabRoutingHelpers`, but let's not try
to tackle that as part of this MR.

Changelog: added

app/graphql/types/repository/blob_type.rb

@@ -32,6 +32,15 @@ module Types
       field :web_path, GraphQL::STRING_TYPE, null: true,
             description: 'Web path of the blob.'
 
+      field :ide_edit_path, GraphQL::STRING_TYPE, null: true,
+            description: 'Web path to edit this blob in the Web IDE.'
+
+      field :fork_and_edit_path, GraphQL::STRING_TYPE, null: true,
+            description: 'Web path to edit this blob using a forked project.'
+
+      field :ide_fork_and_edit_path, GraphQL::STRING_TYPE, null: true,
+            description: 'Web path to edit this blob in the Web IDE using a forked project.'
+
       field :size, GraphQL::INT_TYPE, null: true,
             description: 'Size (in bytes) of the blob.'
 
@@ -53,6 +62,9 @@ module Types
       field :raw_path, GraphQL::STRING_TYPE, null: true,
             description: 'Web path to download the raw blob.'
 
+      field :external_storage_url, GraphQL::STRING_TYPE, null: true,
+            description: 'Web path to download the raw blob via external storage, if enabled.'
+
       field :replace_path, GraphQL::STRING_TYPE, null: true,
             description: 'Web path to replace the blob content.'
 
@@ -72,6 +84,10 @@ module Types
             null: true,
             calls_gitaly: true
 
+      field :can_modify_blob, GraphQL::BOOLEAN_TYPE, null: true, method: :can_modify_blob?,
+            calls_gitaly: true,
+            description: 'Whether the current user can modify the blob.'
+
       def raw_text_blob
         object.data unless object.binary?
       end

app/presenters/blob_presenter.rb

 # frozen_string_literal: true
 
 class BlobPresenter < Gitlab::View::Presenter::Delegated
+  include ApplicationHelper
+  include BlobHelper
+  include DiffHelper
+  include TreeHelper
+  include ChecksCollaboration
+
   presents :blob
 
   def highlight(to: nil, plain: nil)
@@ -40,6 +46,28 @@ class BlobPresenter < Gitlab::View::Presenter::Delegated
     url_helpers.project_create_blob_path(project, ref_qualified_path)
   end
 
+  def fork_and_edit_path
+    fork_path_for_current_user(project, edit_blob_path)
+  end
+
+  def ide_fork_and_edit_path
+    fork_path_for_current_user(project, ide_edit_path)
+  end
+
+  def can_modify_blob?
+    super(blob, project, blob.commit_id)
+  end
+
+  def ide_edit_path
+    super(project, blob.commit_id, blob.path)
+  end
+
+  def external_storage_url
+    return unless static_objects_external_storage_enabled?
+
+    external_storage_url_or_path(url_helpers.project_raw_url(project, ref_qualified_path))
+  end
+
   private
 
   def url_helpers

changelogs/unreleased/323195-add-more-blob-attributes.yml

+---
+title: Add more attributes to the blob GraphQL API
+merge_request: 61155
+author:
+type: added

doc/api/graphql/reference/index.md

@@ -11784,9 +11784,14 @@ Returns [`Tree`](#tree).
 
 | Name | Type | Description |
 | ---- | ---- | ----------- |
+| <a id="repositoryblobcanmodifyblob"></a>`canModifyBlob` | [`Boolean`](#boolean) | Whether the current user can modify the blob. |
 | <a id="repositoryblobeditblobpath"></a>`editBlobPath` | [`String`](#string) | Web path to edit the blob in the old-style editor. |
+| <a id="repositoryblobexternalstorageurl"></a>`externalStorageUrl` | [`String`](#string) | Web path to download the raw blob via external storage, if enabled. |
 | <a id="repositoryblobfiletype"></a>`fileType` | [`String`](#string) | The expected format of the blob based on the extension. |
+| <a id="repositoryblobforkandeditpath"></a>`forkAndEditPath` | [`String`](#string) | Web path to edit this blob using a forked project. |
 | <a id="repositoryblobid"></a>`id` | [`ID!`](#id) | ID of the blob. |
+| <a id="repositoryblobideeditpath"></a>`ideEditPath` | [`String`](#string) | Web path to edit this blob in the Web IDE. |
+| <a id="repositoryblobideforkandeditpath"></a>`ideForkAndEditPath` | [`String`](#string) | Web path to edit this blob in the Web IDE using a forked project. |
 | <a id="repositorybloblfsoid"></a>`lfsOid` | [`String`](#string) | LFS OID of the blob. |
 | <a id="repositoryblobmode"></a>`mode` | [`String`](#string) | Blob mode. |
 | <a id="repositoryblobname"></a>`name` | [`String`](#string) | Blob name. |

spec/graphql/types/repository/blob_type_spec.rb

@@ -25,7 +25,12 @@ RSpec.describe Types::Repository::BlobType do
       :replace_path,
       :simple_viewer,
       :rich_viewer,
-      :plain_data
+      :plain_data,
+      :can_modify_blob,
+      :ide_edit_path,
+      :external_storage_url,
+      :fork_and_edit_path,
+      :ide_fork_and_edit_path
     )
   end
 end

spec/presenters/blob_presenter_spec.rb

@@ -4,11 +4,12 @@ require 'spec_helper'
 
 RSpec.describe BlobPresenter do
   let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:user) { project.owner }
 
   let(:repository) { project.repository }
   let(:blob) { repository.blob_at('HEAD', 'files/ruby/regex.rb') }
 
-  subject(:presenter) { described_class.new(blob) }
+  subject(:presenter) { described_class.new(blob, current_user: user) }
 
   describe '#web_url' do
     it { expect(presenter.web_url).to eq("http://localhost/#{project.full_path}/-/blob/#{blob.commit_id}/#{blob.path}") }
@@ -30,6 +31,42 @@ RSpec.describe BlobPresenter do
     it { expect(presenter.replace_path).to eq("/#{project.full_path}/-/create/#{blob.commit_id}/#{blob.path}") }
   end
 
+  describe '#ide_edit_path' do
+    it { expect(presenter.ide_edit_path).to eq("/-/ide/project/#{project.full_path}/edit/HEAD/-/files/ruby/regex.rb") }
+  end
+
+  describe '#fork_and_edit_path' do
+    it 'generates expected URI + query' do
+      uri = URI.parse(presenter.fork_and_edit_path)
+      query = Rack::Utils.parse_query(uri.query)
+
+      expect(uri.path).to eq("/#{project.full_path}/-/forks")
+      expect(query).to include('continue[to]' => presenter.edit_blob_path, 'namespace_key' => user.namespace_id.to_s)
+    end
+
+    context 'current_user is nil' do
+      let(:user) { nil }
+
+      it { expect(presenter.fork_and_edit_path).to be_nil }
+    end
+  end
+
+  describe '#ide_fork_and_edit_path' do
+    it 'generates expected URI + query' do
+      uri = URI.parse(presenter.ide_fork_and_edit_path)
+      query = Rack::Utils.parse_query(uri.query)
+
+      expect(uri.path).to eq("/#{project.full_path}/-/forks")
+      expect(query).to include('continue[to]' => presenter.ide_edit_path, 'namespace_key' => user.namespace_id.to_s)
+    end
+
+    context 'current_user is nil' do
+      let(:user) { nil }
+
+      it { expect(presenter.ide_fork_and_edit_path).to be_nil }
+    end
+  end
+
   context 'given a Gitlab::Graphql::Representation::TreeEntry' do
     let(:blob) { Gitlab::Graphql::Representation::TreeEntry.new(super(), repository) }