Merge branch 'osw-comment-on-any-line-on-diffs' into 'master'

Comment on any expanded diff line on MRs

See merge request gitlab-org/gitlab-ce!22398

8 files changed, 891 insertions, 31 deletions

diff --git a/spec/controllers/projects/blob_controller_spec.rb b/spec/controllers/projects/blob_controller_spec.rb
index 64b589a6d83..f58aa25cbdd 100644
--- a/spec/controllers/projects/blob_controller_spec.rb
+++ b/spec/controllers/projects/blob_controller_spec.rb
@@ -157,7 +157,7 @@ describe Projects::BlobController do
 
             match_line = JSON.parse(response.body).first
 
-            expect(match_line['type']).to eq('context')
+            expect(match_line['type']).to be_nil
           end
 
           it 'adds bottom match line when "t"o is less than blob size' do
@@ -177,7 +177,7 @@ describe Projects::BlobController do
 
             match_line = JSON.parse(response.body).last
 
-            expect(match_line['type']).to eq('context')
+            expect(match_line['type']).to be_nil
           end
         end
       end
diff --git a/spec/features/merge_request/user_posts_diff_notes_spec.rb b/spec/features/merge_request/user_posts_diff_notes_spec.rb
index fa148715855..51b78d3e7d1 100644
--- a/spec/features/merge_request/user_posts_diff_notes_spec.rb
+++ b/spec/features/merge_request/user_posts_diff_notes_spec.rb
@@ -85,12 +85,13 @@ describe 'Merge request > User posts diff notes', :js do
       # `.line_holder` will be an unfolded line.
       let(:line_holder) { first('#a5cc2925ca8258af241be7e5b0381edf30266302 .line_holder') }
 
-      it 'does not allow commenting on the left side' do
-        should_not_allow_commenting(line_holder, 'left')
+      it 'allows commenting on the left side' do
+        should_allow_commenting(line_holder, 'left')
       end
 
-      it 'does not allow commenting on the right side' do
-        should_not_allow_commenting(line_holder, 'right')
+      it 'allows commenting on the right side' do
+        # Automatically shifts comment box to left side.
+        should_allow_commenting(line_holder, 'right')
       end
     end
   end
@@ -147,8 +148,8 @@ describe 'Merge request > User posts diff notes', :js do
       # `.line_holder` will be an unfolded line.
       let(:line_holder) { first('.line_holder[id="a5cc2925ca8258af241be7e5b0381edf30266302_1_1"]') }
 
-      it 'does not allow commenting' do
-        should_not_allow_commenting line_holder
+      it 'allows commenting' do
+        should_allow_commenting line_holder
       end
     end
 
diff --git a/spec/javascripts/diffs/store/mutations_spec.js b/spec/javascripts/diffs/store/mutations_spec.js
index fed04cbaed8..8821cde76f4 100644
--- a/spec/javascripts/diffs/store/mutations_spec.js
+++ b/spec/javascripts/diffs/store/mutations_spec.js
@@ -98,7 +98,7 @@ describe('DiffsStoreMutations', () => {
     it('should call utils.addContextLines with proper params', () => {
       const options = {
         lineNumbers: { oldLineNumber: 1, newLineNumber: 2 },
-        contextLines: [{ oldLine: 1 }],
+        contextLines: [{ oldLine: 1, newLine: 1, lineCode: 'ff9200_1_1', discussions: [] }],
         fileHash: 'ff9200',
         params: {
           bottom: true,
@@ -110,7 +110,7 @@ describe('DiffsStoreMutations', () => {
         parallelDiffLines: [],
       };
       const state = { diffFiles: [diffFile] };
-      const lines = [{ oldLine: 1 }];
+      const lines = [{ oldLine: 1, newLine: 1 }];
 
       const findDiffFileSpy = spyOnDependency(mutations, 'findDiffFile').and.returnValue(diffFile);
       const removeMatchLineSpy = spyOnDependency(mutations, 'removeMatchLine');
diff --git a/spec/lib/gitlab/diff/file_spec.rb b/spec/lib/gitlab/diff/file_spec.rb
index 2f51642b58e..3417896e259 100644
--- a/spec/lib/gitlab/diff/file_spec.rb
+++ b/spec/lib/gitlab/diff/file_spec.rb
@@ -41,6 +41,52 @@ describe Gitlab::Diff::File do
     end
   end
 
+  describe '#unfold_diff_lines' do
+    let(:unfolded_lines) { double('expanded-lines') }
+    let(:unfolder) { instance_double(Gitlab::Diff::LinesUnfolder) }
+    let(:position) { instance_double(Gitlab::Diff::Position, old_line: 10) }
+
+    before do
+      allow(Gitlab::Diff::LinesUnfolder).to receive(:new) { unfolder }
+    end
+
+    context 'when unfold required' do
+      before do
+        allow(unfolder).to receive(:unfold_required?) { true }
+        allow(unfolder).to receive(:unfolded_diff_lines) { unfolded_lines }
+      end
+
+      it 'changes @unfolded to true' do
+        diff_file.unfold_diff_lines(position)
+
+        expect(diff_file).to be_unfolded
+      end
+
+      it 'updates @diff_lines' do
+        diff_file.unfold_diff_lines(position)
+
+        expect(diff_file.diff_lines).to eq(unfolded_lines)
+      end
+    end
+
+    context 'when unfold not required' do
+      before do
+        allow(unfolder).to receive(:unfold_required?) { false }
+      end
+
+      it 'keeps @unfolded false' do
+        diff_file.unfold_diff_lines(position)
+
+        expect(diff_file).not_to be_unfolded
+      end
+
+      it 'does not update @diff_lines' do
+        expect { diff_file.unfold_diff_lines(position) }
+          .not_to change(diff_file, :diff_lines)
+      end
+    end
+  end
+
   describe '#mode_changed?' do
     it { expect(diff_file.mode_changed?).to be_falsey }
   end
diff --git a/spec/lib/gitlab/diff/lines_unfolder_spec.rb b/spec/lib/gitlab/diff/lines_unfolder_spec.rb
new file mode 100644
index 00000000000..8e00c8e0e30
--- /dev/null
+++ b/spec/lib/gitlab/diff/lines_unfolder_spec.rb
@@ -0,0 +1,750 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Diff::LinesUnfolder do
+  let(:raw_diff) do
+    <<-DIFF.strip_heredoc
+      @@ -7,9 +7,6 @@
+           "tags": ["devel", "development", "nightly"],
+           "desktop-file-name-prefix": "(Development) ",
+           "finish-args": [
+      -        "--share=ipc", "--socket=x11",
+      -        "--socket=wayland",
+      -        "--talk-name=org.gnome.OnlineAccounts",
+               "--talk-name=org.freedesktop.Tracker1",
+               "--filesystem=home",
+               "--talk-name=org.gtk.vfs", "--talk-name=org.gtk.vfs.*",
+      @@ -62,7 +59,7 @@
+               },
+               {
+                   "name": "gnome-desktop",
+      -            "config-opts": ["--disable-debug-tools", "--disable-udev"],
+      +            "config-opts": ["--disable-debug-tools", "--disable-"],
+                   "sources": [
+                       {
+                           "type": "git",
+      @@ -83,11 +80,6 @@
+                   "buildsystem": "meson",
+                   "builddir": true,
+                   "name": "nautilus",
+      -            "config-opts": [
+      -                "-Denable-desktop=false",
+      -                "-Denable-selinux=false",
+      -                "--libdir=/app/lib"
+      -            ],
+                   "sources": [
+                       {
+                           "type": "git",
+    DIFF
+  end
+
+  let(:raw_old_blob) do
+    <<-BLOB.strip_heredoc
+      {
+          "app-id": "org.gnome.Nautilus",
+          "runtime": "org.gnome.Platform",
+          "runtime-version": "master",
+          "sdk": "org.gnome.Sdk",
+          "command": "nautilus",
+          "tags": ["devel", "development", "nightly"],
+          "desktop-file-name-prefix": "(Development) ",
+          "finish-args": [
+              "--share=ipc", "--socket=x11",
+              "--socket=wayland",
+              "--talk-name=org.gnome.OnlineAccounts",
+              "--talk-name=org.freedesktop.Tracker1",
+              "--filesystem=home",
+              "--talk-name=org.gtk.vfs", "--talk-name=org.gtk.vfs.*",
+              "--filesystem=xdg-run/dconf", "--filesystem=~/.config/dconf:ro",
+              "--talk-name=ca.desrt.dconf", "--env=DCONF_USER_CONFIG_DIR=.config/dconf"
+          ],
+          "cleanup": [ "/include", "/share/bash-completion" ],
+          "modules": [
+              {
+                  "name": "exiv2",
+                  "sources": [
+                      {
+                          "type": "archive",
+                          "url": "http://exiv2.org/builds/exiv2-0.26-trunk.tar.gz",
+                          "sha256": "c75e3c4a0811bf700d92c82319373b7a825a2331c12b8b37d41eb58e4f18eafb"
+                      },
+                      {
+                          "type": "shell",
+                          "commands": [
+                              "cp -f /usr/share/gnu-config/config.sub ./config/",
+                              "cp -f /usr/share/gnu-config/config.guess ./config/"
+                          ]
+                      }
+                  ]
+              },
+              {
+                  "name": "gexiv2",
+                  "config-opts": [ "--disable-introspection" ],
+                  "sources": [
+                      {
+                          "type": "git",
+                          "url": "https://git.gnome.org/browse/gexiv2"
+                      }
+                  ]
+              },
+              {
+                  "name": "tracker",
+                  "cleanup": [ "/bin", "/etc", "/libexec" ],
+                  "config-opts": [ "--disable-miner-apps", "--disable-static",
+                                   "--disable-tracker-extract", "--disable-tracker-needle",
+                                   "--disable-tracker-preferences", "--disable-artwork",
+                                   "--disable-tracker-writeback", "--disable-miner-user-guides",
+                                   "--with-bash-completion-dir=no" ],
+                  "sources": [
+                      {
+                          "type": "git",
+                          "url": "https://git.gnome.org/browse/tracker"
+                      }
+                  ]
+              },
+              {
+                  "name": "gnome-desktop",
+                  "config-opts": ["--disable-debug-tools", "--disable-udev"],
+                  "sources": [
+                      {
+                          "type": "git",
+                          "url": "https://git.gnome.org/browse/gnome-desktop"
+                      }
+                  ]
+              },
+              {
+                  "name": "gnome-autoar",
+                  "sources": [
+                      {
+                          "type": "git",
+                          "url": "https://git.gnome.org/browse/gnome-autoar"
+                      }
+                  ]
+              },
+              {
+                  "buildsystem": "meson",
+                  "builddir": true,
+                  "name": "nautilus",
+                  "config-opts": [
+                      "-Denable-desktop=false",
+                      "-Denable-selinux=false",
+                      "--libdir=/app/lib"
+                  ],
+                  "sources": [
+                      {
+                          "type": "git",
+                          "url": "https://gitlab.gnome.org/GNOME/nautilus.git"
+                      }
+                  ]
+              }
+          ]
+      },
+      {
+          "app-id": "foo",
+          "runtime": "foo",
+          "runtime-version": "foo",
+          "sdk": "foo",
+          "command": "foo",
+          "tags": ["foo", "bar", "kux"],
+          "desktop-file-name-prefix": "(Foo) ",
+          {
+            "buildsystem": "meson",
+            "builddir": true,
+            "name": "nautilus",
+            "sources": [
+              {
+                "type": "git",
+                "url": "https://gitlab.gnome.org/GNOME/nautilus.git"
+              }
+            ]
+          }
+      },
+      {
+          "app-id": "foo",
+          "runtime": "foo",
+          "runtime-version": "foo",
+          "sdk": "foo",
+          "command": "foo",
+          "tags": ["foo", "bar", "kux"],
+          "desktop-file-name-prefix": "(Foo) ",
+          {
+            "buildsystem": "meson",
+            "builddir": true,
+            "name": "nautilus",
+            "sources": [
+              {
+                "type": "git",
+                "url": "https://gitlab.gnome.org/GNOME/nautilus.git"
+              }
+            ]
+          }
+      }
+    BLOB
+  end
+
+  let(:project) { create(:project) }
+
+  let(:old_blob) { Gitlab::Git::Blob.new(data: raw_old_blob) }
+
+  let(:diff) do
+    Gitlab::Git::Diff.new(diff: raw_diff,
+                          new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                          old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                          a_mode: "100644",
+                          b_mode: "100644",
+                          new_file: false,
+                          renamed_file: false,
+                          deleted_file: false,
+                          too_large: false)
+  end
+
+  let(:diff_file) do
+    Gitlab::Diff::File.new(diff, repository: project.repository)
+  end
+
+  before do
+    allow(old_blob).to receive(:load_all_data!)
+    allow(diff_file).to receive(:old_blob) { old_blob }
+  end
+
+  subject { described_class.new(diff_file, position) }
+
+  context 'position requires a middle expansion and new match lines' do
+    let(:position) do
+      Gitlab::Diff::Position.new(base_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 start_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 head_sha: "1487062132228de836236c522fe52fed4980a46c",
+                                 old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 position_type:  "text",
+                                 old_line: 43,
+                                 new_line: 40)
+    end
+
+    context 'blob lines' do
+      let(:expected_blob_lines) do
+        [[40, 40, "             \"config-opts\": [ \"--disable-introspection\" ],"],
+         [41, 41, "             \"sources\": ["],
+         [42, 42, "                 {"],
+         [43, 43, "                     \"type\": \"git\","],
+         [44, 44, "                     \"url\": \"https://git.gnome.org/browse/gexiv2\""],
+         [45, 45, "                 }"],
+         [46, 46, "             ]"]]
+      end
+
+      it 'returns the extracted blob lines correctly' do
+        extracted_lines = subject.blob_lines
+
+        expect(extracted_lines.size).to eq(7)
+
+        extracted_lines.each_with_index do |line, i|
+          expect([line.old_line, line.new_line, line.text]).to eq(expected_blob_lines[i])
+        end
+      end
+    end
+
+    context 'diff lines' do
+      let(:expected_diff_lines) do
+        [[7, 7, "@@ -7,9 +7,6 @@"],
+         [7, 7, "     \"tags\": [\"devel\", \"development\", \"nightly\"],"],
+         [8, 8, "     \"desktop-file-name-prefix\": \"(Development) \","],
+         [9, 9, "     \"finish-args\": ["],
+         [10, 10, "-        \"--share=ipc\", \"--socket=x11\","],
+         [11, 10, "-        \"--socket=wayland\","],
+         [12, 10, "-        \"--talk-name=org.gnome.OnlineAccounts\","],
+         [13, 10, "         \"--talk-name=org.freedesktop.Tracker1\","],
+         [14, 11, "         \"--filesystem=home\","],
+         [15, 12, "         \"--talk-name=org.gtk.vfs\", \"--talk-name=org.gtk.vfs.*\","],
+
+         # New match line
+         [40, 37, "@@ -40,7+37,7 @@"],
+
+         # Injected blob lines
+         [40, 37, "             \"config-opts\": [ \"--disable-introspection\" ],"],
+         [41, 38, "             \"sources\": ["],
+         [42, 39, "                 {"],
+         [43, 40, "                     \"type\": \"git\","], # comment
+         [44, 41, "                     \"url\": \"https://git.gnome.org/browse/gexiv2\""],
+         [45, 42, "                 }"],
+         [46, 43, "             ]"],
+         # end
+
+         # Second match line
+         [62, 59, "@@ -62,7+59,7 @@"],
+
+         [62, 59, "         },"],
+         [63, 60, "         {"],
+         [64, 61, "             \"name\": \"gnome-desktop\","],
+         [65, 62, "-            \"config-opts\": [\"--disable-debug-tools\", \"--disable-udev\"],"],
+         [66, 62, "+            \"config-opts\": [\"--disable-debug-tools\", \"--disable-\"],"],
+         [66, 63, "             \"sources\": ["],
+         [67, 64, "                 {"],
+         [68, 65, "                     \"type\": \"git\","],
+         [83, 80, "@@ -83,11 +80,6 @@"],
+         [83, 80, "             \"buildsystem\": \"meson\","],
+         [84, 81, "             \"builddir\": true,"],
+         [85, 82, "             \"name\": \"nautilus\","],
+         [86, 83, "-            \"config-opts\": ["],
+         [87, 83, "-                \"-Denable-desktop=false\","],
+         [88, 83, "-                \"-Denable-selinux=false\","],
+         [89, 83, "-                \"--libdir=/app/lib\""],
+         [90, 83, "-            ],"],
+         [91, 83, "             \"sources\": ["],
+         [92, 84, "                 {"],
+         [93, 85, "                     \"type\": \"git\","]]
+      end
+
+      it 'return merge of blob lines with diff lines correctly' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        expected_diff_lines.each_with_index do |expected_line, i|
+          line = new_diff_lines[i]
+
+          expect([line.old_pos, line.new_pos, line.text])
+            .to eq([expected_line[0], expected_line[1], expected_line[2]])
+        end
+      end
+
+      it 'merged lines have correct line codes' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        new_diff_lines.each_with_index do |line, i|
+          old_pos, new_pos = expected_diff_lines[i][0], expected_diff_lines[i][1]
+
+          unless line.type == 'match'
+            expect(line.line_code).to eq(Gitlab::Git.diff_line_code(diff_file.file_path, new_pos, old_pos))
+          end
+        end
+      end
+    end
+  end
+
+  context 'position requires a middle expansion and no top match line' do
+    let(:position) do
+      Gitlab::Diff::Position.new(base_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 start_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 head_sha: "1487062132228de836236c522fe52fed4980a46c",
+                                 old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 position_type:  "text",
+                                 old_line: 16,
+                                 new_line: 17)
+    end
+
+    context 'blob lines' do
+      let(:expected_blob_lines) do
+        [[16, 16, "         \"--filesystem=xdg-run/dconf\", \"--filesystem=~/.config/dconf:ro\","],
+         [17, 17, "         \"--talk-name=ca.desrt.dconf\", \"--env=DCONF_USER_CONFIG_DIR=.config/dconf\""],
+         [18, 18, "     ],"],
+         [19, 19, "     \"cleanup\": [ \"/include\", \"/share/bash-completion\" ],"]]
+      end
+
+      it 'returns the extracted blob lines correctly' do
+        extracted_lines = subject.blob_lines
+
+        expect(extracted_lines.size).to eq(4)
+
+        extracted_lines.each_with_index do |line, i|
+          expect([line.old_line, line.new_line, line.text]).to eq(expected_blob_lines[i])
+        end
+      end
+    end
+
+    context 'diff lines' do
+      let(:expected_diff_lines) do
+        [[7, 7, "@@ -7,9 +7,6 @@"],
+         [7, 7, "     \"tags\": [\"devel\", \"development\", \"nightly\"],"],
+         [8, 8, "     \"desktop-file-name-prefix\": \"(Development) \","],
+         [9, 9, "     \"finish-args\": ["],
+         [10, 10, "-        \"--share=ipc\", \"--socket=x11\","],
+         [11, 10, "-        \"--socket=wayland\","],
+         [12, 10, "-        \"--talk-name=org.gnome.OnlineAccounts\","],
+         [13, 10, "         \"--talk-name=org.freedesktop.Tracker1\","],
+         [14, 11, "         \"--filesystem=home\","],
+         [15, 12, "         \"--talk-name=org.gtk.vfs\", \"--talk-name=org.gtk.vfs.*\","],
+         # No new match needed
+
+         # Injected blob lines
+         [16, 13, "         \"--filesystem=xdg-run/dconf\", \"--filesystem=~/.config/dconf:ro\","],
+         [17, 14, "         \"--talk-name=ca.desrt.dconf\", \"--env=DCONF_USER_CONFIG_DIR=.config/dconf\""],
+         [18, 15, "     ],"],
+         [19, 16, "     \"cleanup\": [ \"/include\", \"/share/bash-completion\" ],"],
+         # end
+
+         # Second match line
+         [62, 59, "@@ -62,4+59,4 @@"],
+
+         [62, 59, "         },"],
+         [63, 60, "         {"],
+         [64, 61, "             \"name\": \"gnome-desktop\","],
+         [65, 62, "-            \"config-opts\": [\"--disable-debug-tools\", \"--disable-udev\"],"],
+         [66, 62, "+            \"config-opts\": [\"--disable-debug-tools\", \"--disable-\"],"],
+         [66, 63, "             \"sources\": ["],
+         [67, 64, "                 {"],
+         [68, 65, "                     \"type\": \"git\","],
+         [83, 80, "@@ -83,11 +80,6 @@"],
+         [83, 80, "             \"buildsystem\": \"meson\","],
+         [84, 81, "             \"builddir\": true,"],
+         [85, 82, "             \"name\": \"nautilus\","],
+         [86, 83, "-            \"config-opts\": ["],
+         [87, 83, "-                \"-Denable-desktop=false\","],
+         [88, 83, "-                \"-Denable-selinux=false\","],
+         [89, 83, "-                \"--libdir=/app/lib\""],
+         [90, 83, "-            ],"],
+         [91, 83, "             \"sources\": ["],
+         [92, 84, "                 {"],
+         [93, 85, "                     \"type\": \"git\","]]
+      end
+
+      it 'return merge of blob lines with diff lines correctly' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        expected_diff_lines.each_with_index do |expected_line, i|
+          line = new_diff_lines[i]
+
+          expect([line.old_pos, line.new_pos, line.text])
+            .to eq([expected_line[0], expected_line[1], expected_line[2]])
+        end
+      end
+
+      it 'merged lines have correct line codes' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        new_diff_lines.each_with_index do |line, i|
+          old_pos, new_pos = expected_diff_lines[i][0], expected_diff_lines[i][1]
+
+          unless line.type == 'match'
+            expect(line.line_code).to eq(Gitlab::Git.diff_line_code(diff_file.file_path, new_pos, old_pos))
+          end
+        end
+      end
+    end
+  end
+
+  context 'position requires a middle expansion and no bottom match line' do
+    let(:position) do
+      Gitlab::Diff::Position.new(base_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 start_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 head_sha: "1487062132228de836236c522fe52fed4980a46c",
+                                 old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 position_type:  "text",
+                                 old_line: 82,
+                                 new_line: 79)
+    end
+
+    context 'blob lines' do
+      let(:expected_blob_lines) do
+        [[79, 79, "                 }"],
+         [80, 80, "             ]"],
+         [81, 81, "         },"],
+         [82, 82, "         {"]]
+      end
+
+      it 'returns the extracted blob lines correctly' do
+        extracted_lines = subject.blob_lines
+
+        expect(extracted_lines.size).to eq(4)
+
+        extracted_lines.each_with_index do |line, i|
+          expect([line.old_line, line.new_line, line.text]).to eq(expected_blob_lines[i])
+        end
+      end
+    end
+
+    context 'diff lines' do
+      let(:expected_diff_lines) do
+        [[7, 7, "@@ -7,9 +7,6 @@"],
+         [7, 7, "     \"tags\": [\"devel\", \"development\", \"nightly\"],"],
+         [8, 8, "     \"desktop-file-name-prefix\": \"(Development) \","],
+         [9, 9, "     \"finish-args\": ["],
+         [10, 10, "-        \"--share=ipc\", \"--socket=x11\","],
+         [11, 10, "-        \"--socket=wayland\","],
+         [12, 10, "-        \"--talk-name=org.gnome.OnlineAccounts\","],
+         [13, 10, "         \"--talk-name=org.freedesktop.Tracker1\","],
+         [14, 11, "         \"--filesystem=home\","],
+         [15, 12, "         \"--talk-name=org.gtk.vfs\", \"--talk-name=org.gtk.vfs.*\","],
+         [62, 59, "@@ -62,7 +59,7 @@"],
+         [62, 59, "         },"],
+         [63, 60, "         {"],
+         [64, 61, "             \"name\": \"gnome-desktop\","],
+         [65, 62, "-            \"config-opts\": [\"--disable-debug-tools\", \"--disable-udev\"],"],
+         [66, 62, "+            \"config-opts\": [\"--disable-debug-tools\", \"--disable-\"],"],
+         [66, 63, "             \"sources\": ["],
+         [67, 64, "                 {"],
+         [68, 65, "                     \"type\": \"git\","],
+
+         # New top match line
+         [79, 76, "@@ -79,4+76,4 @@"],
+
+         # Injected blob lines
+         [79, 76, "                 }"],
+         [80, 77, "             ]"],
+         [81, 78, "         },"],
+         [82, 79, "         {"],
+         # end
+
+         # No new second match line
+         [83, 80, "             \"buildsystem\": \"meson\","],
+         [84, 81, "             \"builddir\": true,"],
+         [85, 82, "             \"name\": \"nautilus\","],
+         [86, 83, "-            \"config-opts\": ["],
+         [87, 83, "-                \"-Denable-desktop=false\","],
+         [88, 83, "-                \"-Denable-selinux=false\","],
+         [89, 83, "-                \"--libdir=/app/lib\""],
+         [90, 83, "-            ],"],
+         [91, 83, "             \"sources\": ["],
+         [92, 84, "                 {"],
+         [93, 85, "                     \"type\": \"git\","]]
+      end
+
+      it 'return merge of blob lines with diff lines correctly' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        expected_diff_lines.each_with_index do |expected_line, i|
+          line = new_diff_lines[i]
+
+          expect([line.old_pos, line.new_pos, line.text])
+            .to eq([expected_line[0], expected_line[1], expected_line[2]])
+        end
+      end
+
+      it 'merged lines have correct line codes' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        new_diff_lines.each_with_index do |line, i|
+          old_pos, new_pos = expected_diff_lines[i][0], expected_diff_lines[i][1]
+
+          unless line.type == 'match'
+            expect(line.line_code).to eq(Gitlab::Git.diff_line_code(diff_file.file_path, new_pos, old_pos))
+          end
+        end
+      end
+    end
+  end
+
+  context 'position requires a short top expansion' do
+    let(:position) do
+      Gitlab::Diff::Position.new(base_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 start_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 head_sha: "1487062132228de836236c522fe52fed4980a46c",
+                                 old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 position_type: "text",
+                                 old_line: 6,
+                                 new_line: 6)
+    end
+
+    context 'blob lines' do
+      let(:expected_blob_lines) do
+        [[3, 3, "     \"runtime\": \"org.gnome.Platform\","],
+         [4, 4, "     \"runtime-version\": \"master\","],
+         [5, 5, "     \"sdk\": \"org.gnome.Sdk\","],
+         [6, 6, "     \"command\": \"nautilus\","]]
+      end
+
+      it 'returns the extracted blob lines correctly' do
+        extracted_lines = subject.blob_lines
+
+        expect(extracted_lines.size).to eq(4)
+
+        extracted_lines.each_with_index do |line, i|
+          expect([line.old_line, line.new_line, line.text]).to eq(expected_blob_lines[i])
+        end
+      end
+    end
+
+    context 'diff lines' do
+      let(:expected_diff_lines) do
+        # New match line
+        [[3, 3, "@@ -3,4+3,4 @@"],
+
+         # Injected blob lines
+         [3, 3, "     \"runtime\": \"org.gnome.Platform\","],
+         [4, 4, "     \"runtime-version\": \"master\","],
+         [5, 5, "     \"sdk\": \"org.gnome.Sdk\","],
+         [6, 6, "     \"command\": \"nautilus\","],
+         # end
+         [7, 7, "     \"tags\": [\"devel\", \"development\", \"nightly\"],"],
+         [8, 8, "     \"desktop-file-name-prefix\": \"(Development) \","],
+         [9, 9, "     \"finish-args\": ["],
+         [10, 10, "-        \"--share=ipc\", \"--socket=x11\","],
+         [11, 10, "-        \"--socket=wayland\","],
+         [12, 10, "-        \"--talk-name=org.gnome.OnlineAccounts\","],
+         [13, 10, "         \"--talk-name=org.freedesktop.Tracker1\","],
+         [14, 11, "         \"--filesystem=home\","],
+         [15, 12, "         \"--talk-name=org.gtk.vfs\", \"--talk-name=org.gtk.vfs.*\","],
+         [62, 59, "@@ -62,7 +59,7 @@"],
+         [62, 59, "         },"],
+         [63, 60, "         {"],
+         [64, 61, "             \"name\": \"gnome-desktop\","],
+         [65, 62, "-            \"config-opts\": [\"--disable-debug-tools\", \"--disable-udev\"],"],
+         [66, 62, "+            \"config-opts\": [\"--disable-debug-tools\", \"--disable-\"],"],
+         [66, 63, "             \"sources\": ["],
+         [67, 64, "                 {"],
+         [68, 65, "                     \"type\": \"git\","],
+         [83, 80, "@@ -83,11 +80,6 @@"],
+         [83, 80, "             \"buildsystem\": \"meson\","],
+         [84, 81, "             \"builddir\": true,"],
+         [85, 82, "             \"name\": \"nautilus\","],
+         [86, 83, "-            \"config-opts\": ["],
+         [87, 83, "-                \"-Denable-desktop=false\","],
+         [88, 83, "-                \"-Denable-selinux=false\","],
+         [89, 83, "-                \"--libdir=/app/lib\""],
+         [90, 83, "-            ],"],
+         [91, 83, "             \"sources\": ["],
+         [92, 84, "                 {"],
+         [93, 85, "                     \"type\": \"git\","]]
+      end
+
+      it 'return merge of blob lines with diff lines correctly' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        expected_diff_lines.each_with_index do |expected_line, i|
+          line = new_diff_lines[i]
+
+          expect([line.old_pos, line.new_pos, line.text])
+            .to eq([expected_line[0], expected_line[1], expected_line[2]])
+        end
+      end
+
+      it 'merged lines have correct line codes' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        new_diff_lines.each_with_index do |line, i|
+          old_pos, new_pos = expected_diff_lines[i][0], expected_diff_lines[i][1]
+
+          unless line.type == 'match'
+            expect(line.line_code).to eq(Gitlab::Git.diff_line_code(diff_file.file_path, new_pos, old_pos))
+          end
+        end
+      end
+    end
+  end
+
+  context 'position sits between two match lines (no expasion needed)' do
+    let(:position) do
+      Gitlab::Diff::Position.new(base_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 start_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 head_sha: "1487062132228de836236c522fe52fed4980a46c",
+                                 old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 position_type: "text",
+                                 old_line: 64,
+                                 new_line: 61)
+    end
+
+    context 'diff lines' do
+      it 'returns nil' do
+        expect(subject.unfolded_diff_lines).to be_nil
+      end
+    end
+  end
+
+  context 'position requires bottom expansion and new match lines' do
+    let(:position) do
+      Gitlab::Diff::Position.new(base_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 start_sha: "1c59dfa64afbea8c721bb09a06a9d326c952ea19",
+                                 head_sha: "1487062132228de836236c522fe52fed4980a46c",
+                                 old_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 new_path: "build-aux/flatpak/org.gnome.Nautilus.json",
+                                 position_type: "text",
+                                 old_line: 107,
+                                 new_line: 99)
+    end
+
+    context 'blob lines' do
+      let(:expected_blob_lines) do
+        [[104, 104, "     \"sdk\": \"foo\","],
+         [105, 105, "     \"command\": \"foo\","],
+         [106, 106, "     \"tags\": [\"foo\", \"bar\", \"kux\"],"],
+         [107, 107, "     \"desktop-file-name-prefix\": \"(Foo) \","],
+         [108, 108, "     {"],
+         [109, 109, "       \"buildsystem\": \"meson\","],
+         [110, 110, "       \"builddir\": true,"]]
+      end
+
+      it 'returns the extracted blob lines correctly' do
+        extracted_lines = subject.blob_lines
+
+        expect(extracted_lines.size).to eq(7)
+
+        extracted_lines.each_with_index do |line, i|
+          expect([line.old_line, line.new_line, line.text]).to eq(expected_blob_lines[i])
+        end
+      end
+    end
+
+    context 'diff lines' do
+      let(:expected_diff_lines) do
+        [[7, 7, "@@ -7,9 +7,6 @@"],
+         [7, 7, "     \"tags\": [\"devel\", \"development\", \"nightly\"],"],
+         [8, 8, "     \"desktop-file-name-prefix\": \"(Development) \","],
+         [9, 9, "     \"finish-args\": ["],
+         [10, 10, "-        \"--share=ipc\", \"--socket=x11\","],
+         [11, 10, "-        \"--socket=wayland\","],
+         [12, 10, "-        \"--talk-name=org.gnome.OnlineAccounts\","],
+         [13, 10, "         \"--talk-name=org.freedesktop.Tracker1\","],
+         [14, 11, "         \"--filesystem=home\","],
+         [15, 12, "         \"--talk-name=org.gtk.vfs\", \"--talk-name=org.gtk.vfs.*\","],
+         [62, 59, "@@ -62,7 +59,7 @@"],
+         [62, 59, "         },"],
+         [63, 60, "         {"],
+         [64, 61, "             \"name\": \"gnome-desktop\","],
+         [65, 62, "-            \"config-opts\": [\"--disable-debug-tools\", \"--disable-udev\"],"],
+         [66, 62, "+            \"config-opts\": [\"--disable-debug-tools\", \"--disable-\"],"],
+         [66, 63, "             \"sources\": ["],
+         [67, 64, "                 {"],
+         [68, 65, "                     \"type\": \"git\","],
+         [83, 80, "@@ -83,11 +80,6 @@"],
+         [83, 80, "             \"buildsystem\": \"meson\","],
+         [84, 81, "             \"builddir\": true,"],
+         [85, 82, "             \"name\": \"nautilus\","],
+         [86, 83, "-            \"config-opts\": ["],
+         [87, 83, "-                \"-Denable-desktop=false\","],
+         [88, 83, "-                \"-Denable-selinux=false\","],
+         [89, 83, "-                \"--libdir=/app/lib\""],
+         [90, 83, "-            ],"],
+         [91, 83, "             \"sources\": ["],
+         [92, 84, "                 {"],
+         [93, 85, "                     \"type\": \"git\","],
+         # New match line
+         [104, 96, "@@ -104,7+96,7 @@"],
+
+         # Injected blob lines
+         [104, 96, "     \"sdk\": \"foo\","],
+         [105, 97, "     \"command\": \"foo\","],
+         [106, 98, "     \"tags\": [\"foo\", \"bar\", \"kux\"],"],
+         [107, 99, "     \"desktop-file-name-prefix\": \"(Foo) \","],
+         [108, 100, "     {"],
+         [109, 101, "       \"buildsystem\": \"meson\","],
+         [110, 102, "       \"builddir\": true,"]]
+        # end
+      end
+
+      it 'return merge of blob lines with diff lines correctly' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        expected_diff_lines.each_with_index do |expected_line, i|
+          line = new_diff_lines[i]
+
+          expect([line.old_pos, line.new_pos, line.text])
+            .to eq([expected_line[0], expected_line[1], expected_line[2]])
+        end
+      end
+
+      it 'merged lines have correct line codes' do
+        new_diff_lines = subject.unfolded_diff_lines
+
+        new_diff_lines.each_with_index do |line, i|
+          old_pos, new_pos = expected_diff_lines[i][0], expected_diff_lines[i][1]
+
+          unless line.type == 'match'
+            expect(line.line_code).to eq(Gitlab::Git.diff_line_code(diff_file.file_path, new_pos, old_pos))
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/services/merge_requests/reload_diffs_service_spec.rb b/spec/services/merge_requests/reload_diffs_service_spec.rb
index 546c9f277c5..5acd01828cb 100644
--- a/spec/services/merge_requests/reload_diffs_service_spec.rb
+++ b/spec/services/merge_requests/reload_diffs_service_spec.rb
@@ -31,32 +31,11 @@ describe MergeRequests::ReloadDiffsService, :use_clean_rails_memory_store_cachin
     end
 
     context 'cache clearing' do
-      before do
-        allow_any_instance_of(Gitlab::Diff::File).to receive(:text?).and_return(true)
-        allow_any_instance_of(Gitlab::Diff::File).to receive(:diffable?).and_return(true)
-      end
-
-      it 'retrieves the diff files to cache the highlighted result' do
-        new_diff = merge_request.create_merge_request_diff
-        cache_key = new_diff.diffs_collection.cache_key
-
-        expect(merge_request).to receive(:create_merge_request_diff).and_return(new_diff)
-        expect(Rails.cache).to receive(:read).with(cache_key).and_call_original
-        expect(Rails.cache).to receive(:write).with(cache_key, anything, anything).and_call_original
-
-        subject.execute
-      end
-
       it 'clears the cache for older diffs on the merge request' do
         old_diff = merge_request.merge_request_diff
         old_cache_key = old_diff.diffs_collection.cache_key
-        new_diff = merge_request.create_merge_request_diff
-        new_cache_key = new_diff.diffs_collection.cache_key
 
-        expect(merge_request).to receive(:create_merge_request_diff).and_return(new_diff)
         expect(Rails.cache).to receive(:delete).with(old_cache_key).and_call_original
-        expect(Rails.cache).to receive(:read).with(new_cache_key).and_call_original
-        expect(Rails.cache).to receive(:write).with(new_cache_key, anything, anything).and_call_original
 
         subject.execute
       end
diff --git a/spec/services/notes/create_service_spec.rb b/spec/services/notes/create_service_spec.rb
index b1290fd0d47..80b015d4cd0 100644
--- a/spec/services/notes/create_service_spec.rb
+++ b/spec/services/notes/create_service_spec.rb
@@ -57,6 +57,57 @@ describe Notes::CreateService do
       end
     end
 
+    context 'noteable highlight cache clearing' do
+      let(:project_with_repo) { create(:project, :repository) }
+      let(:merge_request) do
+        create(:merge_request, source_project: project_with_repo,
+                               target_project: project_with_repo)
+      end
+
+      let(:position) do
+        Gitlab::Diff::Position.new(old_path: "files/ruby/popen.rb",
+                                   new_path: "files/ruby/popen.rb",
+                                   old_line: nil,
+                                   new_line: 14,
+                                   diff_refs: merge_request.diff_refs)
+      end
+
+      let(:new_opts) do
+        opts.merge(in_reply_to_discussion_id: nil,
+                   type: 'DiffNote',
+                   noteable_type: 'MergeRequest',
+                   noteable_id: merge_request.id,
+                   position: position.to_h)
+      end
+
+      before do
+        allow_any_instance_of(Gitlab::Diff::Position)
+          .to receive(:unfolded_diff?) { true }
+      end
+
+      it 'clears noteable diff cache when it was unfolded for the note position' do
+        expect_any_instance_of(Gitlab::Diff::HighlightCache).to receive(:clear)
+
+        described_class.new(project_with_repo, user, new_opts).execute
+      end
+
+      it 'does not clear cache when note is not the first of the discussion' do
+        prev_note =
+          create(:diff_note_on_merge_request, noteable: merge_request,
+                                              project: project_with_repo)
+        reply_opts =
+          opts.merge(in_reply_to_discussion_id: prev_note.discussion_id,
+                     type: 'DiffNote',
+                     noteable_type: 'MergeRequest',
+                     noteable_id: merge_request.id,
+                     position: position.to_h)
+
+        expect(merge_request).not_to receive(:diffs)
+
+        described_class.new(project_with_repo, user, reply_opts).execute
+      end
+    end
+
     context 'note diff file' do
       let(:project_with_repo) { create(:project, :repository) }
       let(:merge_request) do
diff --git a/spec/services/notes/destroy_service_spec.rb b/spec/services/notes/destroy_service_spec.rb
index 64445be560e..b1f4e87e8ea 100644
--- a/spec/services/notes/destroy_service_spec.rb
+++ b/spec/services/notes/destroy_service_spec.rb
@@ -21,5 +21,38 @@ describe Notes::DestroyService do
       expect { described_class.new(project, user).execute(note) }
         .to change { user.todos_pending_count }.from(1).to(0)
     end
+
+    context 'noteable highlight cache clearing' do
+      let(:repo_project) { create(:project, :repository) }
+      let(:merge_request) do
+        create(:merge_request, source_project: repo_project,
+                               target_project: repo_project)
+      end
+
+      let(:note) do
+        create(:diff_note_on_merge_request, project: repo_project,
+                                            noteable: merge_request)
+      end
+
+      before do
+        allow(note.position).to receive(:unfolded_diff?) { true }
+      end
+
+      it 'clears noteable diff cache when it was unfolded for the note position' do
+        expect(merge_request).to receive_message_chain(:diffs, :clear_cache)
+
+        described_class.new(repo_project, user).execute(note)
+      end
+
+      it 'does not clear cache when note is not the first of the discussion' do
+        reply_note = create(:diff_note_on_merge_request, in_reply_to: note,
+                                                         project: repo_project,
+                                                         noteable: merge_request)
+
+        expect(merge_request).not_to receive(:diffs)
+
+        described_class.new(repo_project, user).execute(reply_note)
+      end
+    end
   end
 end