Add full option for blob diff action

Returns all diff lines for frontend if full is true.
Turn UnfoldForm into presenter, and move controller logic to presenter.

app/controllers/projects/blob_controller.rb

@@ -90,20 +90,9 @@ class Projects::BlobController < Projects::ApplicationController
   def diff
     apply_diff_view_cookie!
 
-    @blob.load_all_data!
-    @lines = @blob.present.highlight.lines
-
-    @form = UnfoldForm.new(params.to_unsafe_h)
-
-    @lines = @lines[@form.since - 1..@form.to - 1].map(&:html_safe)
-
-    if @form.bottom?
-      @match_line = ''
-    else
-      lines_length = @lines.length - 1
-      line = [@form.since, lines_length].join(',')
-      @match_line = "@@ -#{line}+#{line} @@"
-    end
+    @form = Blobs::UnfoldPresenter.new(blob, params.to_unsafe_h)
+    @lines = @form.lines
+    @match_line = @form.match_line_text
 
     # We can keep only 'render_diff_lines' from this conditional when
     # https://gitlab.com/gitlab-org/gitlab-ce/issues/44988 is done
@@ -231,6 +220,8 @@ class Projects::BlobController < Projects::ApplicationController
   end
 
   def validate_diff_params
+    return if params[:full]
+
     if [:since, :to, :offset].any? { |key| params[key].blank? }
       head :ok
     end

app/presenters/blobs/unfold_presenter.rb

+# frozen_string_literal: true
+
+require 'gt_one_coercion'
+
+module Blobs
+  class UnfoldPresenter < BlobPresenter
+    include Virtus.model
+    include Gitlab::Utils::StrongMemoize
+
+    attribute :full, Boolean, default: false
+    attribute :since, GtOneCoercion
+    attribute :to, GtOneCoercion
+    attribute :bottom, Boolean
+    attribute :unfold, Boolean, default: true
+    attribute :offset, Integer
+    attribute :indent, Integer, default: 0
+
+    def initialize(blob, params)
+      @subject = blob
+      @all_lines = highlight.lines
+      super(params)
+
+      if full?
+        self.attributes = { since: 1, to: @all_lines.size, bottom: false, unfold: false, offset: 0, indent: 0 }
+      end
+    end
+
+    def lines
+      strong_memoize(:lines) do
+        lines = @all_lines
+        lines = lines[since - 1..to - 1] unless full?
+        lines.map(&:html_safe)
+      end
+    end
+
+    def match_line_text
+      return '' if bottom?
+
+      lines_length = lines.length - 1
+      line = [since, lines_length].join(',')
+      "@@ -#{line}+#{line} @@"
+    end
+  end
+end

lib/unfold_form.rb

-# frozen_string_literal: true
-
-require_relative 'gt_one_coercion'
-
-class UnfoldForm
-  include Virtus.model
-
-  attribute :since, GtOneCoercion
-  attribute :to, GtOneCoercion
-  attribute :bottom, Boolean
-  attribute :unfold, Boolean, default: true
-  attribute :offset, Integer
-  attribute :indent, Integer, default: 0
-end

spec/controllers/projects/blob_controller_spec.rb

@@ -192,6 +192,18 @@ describe Projects::BlobController do
 
             expect(match_line['type']).to be_nil
           end
+
+          it 'returns all lines if "full" is true' do
+            commit_id = project.repository.commit('master').id
+            blob = project.repository.blob_at(commit_id, 'CHANGELOG')
+            do_get(full: true, from_merge_request: true, bottom: true)
+
+            match_lines = JSON.parse(response.body)
+
+            expect(match_lines.size).to eq(blob.lines.count - 1)
+            expect(match_lines.last['type']).to be_nil
+            expect(match_lines.last['text']).to include(blob.lines.last)
+          end
         end
       end
     end

spec/presenters/blobs/unfold_presenter_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Blobs::UnfoldPresenter do
+  include FakeBlobHelpers
+
+  let(:project) { create(:project, :repository) }
+  let(:blob) { fake_blob(path: 'foo', data: "1\n2\n3") }
+  let(:subject) { described_class.new(blob, params) }
+
+  describe '#initialize' do
+    context 'when full is false' do
+      let(:params) { { full: false, since: 2, to: 3, bottom: false, offset: 1, indent: 1 } }
+
+      it 'sets attributes' do
+        result = subject
+
+        expect(result.full?).to eq(false)
+        expect(result.since).to eq(2)
+        expect(result.to).to eq(3)
+        expect(result.bottom).to eq(false)
+        expect(result.offset).to eq(1)
+        expect(result.indent).to eq(1)
+      end
+    end
+
+    context 'when full is true' do
+      let(:params) { { full: true, since: 2, to: 3, bottom: false, offset: 1, indent: 1 } }
+
+      it 'sets other attributes' do
+        result = subject
+
+        expect(result.full?).to eq(true)
+        expect(result.since).to eq(1)
+        expect(result.to).to eq(blob.lines.size)
+        expect(result.bottom).to eq(false)
+        expect(result.offset).to eq(0)
+        expect(result.indent).to eq(0)
+      end
+    end
+  end
+
+  describe '#lines' do
+    context 'when scope is specified' do
+      let(:params) { { since: 2, to: 3 } }
+
+      it 'returns lines cropped by params' do
+        expect(subject.lines.size).to eq(2)
+        expect(subject.lines[0]).to include('LC2')
+        expect(subject.lines[1]).to include('LC3')
+      end
+    end
+
+    context 'when full is true' do
+      let(:params) { { full: true } }
+
+      it 'returns all lines' do
+        expect(subject.lines.size).to eq(3)
+        expect(subject.lines[0]).to include('LC1')
+        expect(subject.lines[1]).to include('LC2')
+        expect(subject.lines[2]).to include('LC3')
+      end
+    end
+  end
+
+  describe '#match_line_text' do
+    context 'when bottom is true' do
+      let(:params) { { since: 2, to: 3, bottom: true } }
+
+      it 'returns empty string' do
+        expect(subject.match_line_text).to eq('')
+      end
+    end
+
+    context 'when bottom is false' do
+      let(:params) { { since: 2, to: 3, bottom: false } }
+
+      it 'returns match line string' do
+        expect(subject.match_line_text).to eq("@@ -2,1+2,1 @@")
+      end
+    end
+  end
+end