Merge branch 'master' into fl-prettify-2

* master: (74 commits)
  Add changelog for 2fa filter in users api
  Add 2FA filter to users API for admins only
  Fix project creation for user endpoint bug
  Flowdock uses Gitaly, not Grit
  Add missing changelog type to docs
  Removes 'no job log' from trace action
  Fix missing namespace for some internal users
  Dedupe yarn dependencies
  Downgrade MySQL CI service from 8.0 to 5.7
  Atomic internal ids for all models
  Add documentation on how to configure Redis Sentinel by persistent class
  Update CHANGELOG.md for 10.7.0
  Update index.md
  Resolve "Text from the diff is showing within a table header inside the discussion after the discussion is resolved"
  Ignore ordering in IssueDueSchedulerWorker spec
  Don't include lfs_file_locks data in export bundle
  Documentation: Frontend Building Checklist
  Fix a documentation typo for GitLab pages
  Refactored activity calendar
  Add an API endpoint to download git repository snapshots
  ...

44 files changed, 1132 insertions, 390 deletions

diff --git a/app/assets/javascripts/boards/models/list.js b/app/assets/javascripts/boards/models/list.js
index e210d69895e..7144f4190e7 100644
--- a/app/assets/javascripts/boards/models/list.js
+++ b/app/assets/javascripts/boards/models/list.js
@@ -113,6 +113,8 @@ class List {
         issue.id = data.id;
         issue.iid = data.iid;
         issue.project = data.project;
+        issue.path = data.real_path;
+        issue.referencePath = data.reference_path;
 
         if (this.issuesSize > 1) {
           const moveBeforeId = this.issues[1].id;
diff --git a/app/assets/javascripts/create_merge_request_dropdown.js b/app/assets/javascripts/create_merge_request_dropdown.js
index fb1fc9cd32e..a88b6971f90 100644
--- a/app/assets/javascripts/create_merge_request_dropdown.js
+++ b/app/assets/javascripts/create_merge_request_dropdown.js
@@ -84,20 +84,21 @@ export default class CreateMergeRequestDropdown {
         if (data.can_create_branch) {
           this.available();
           this.enable();
+          this.updateBranchName(data.suggested_branch_name);
 
           if (!this.droplabInitialized) {
             this.droplabInitialized = true;
             this.initDroplab();
             this.bindEvents();
           }
-        } else if (data.has_related_branch) {
+        } else {
           this.hide();
         }
       })
       .catch(() => {
         this.unavailable();
         this.disable();
-        Flash('Failed to check if a new branch can be created.');
+        Flash(__('Failed to check related branches.'));
       });
   }
 
@@ -409,13 +410,16 @@ export default class CreateMergeRequestDropdown {
     this.unavailableButton.classList.remove('hide');
   }
 
+  updateBranchName(suggestedBranchName) {
+    this.branchInput.value = suggestedBranchName;
+    this.updateCreatePaths('branch', suggestedBranchName);
+  }
+
   updateInputState(target, ref, result) {
     // target - 'branch' or 'ref' - which the input field we are searching a ref for.
     // ref - string - what a user typed.
     // result - string - what has been found on backend.
 
-    const pathReplacement = `$1${ref}`;
-
     // If a found branch equals exact the same text a user typed,
     // that means a new branch cannot be created as it already exists.
     if (ref === result) {
@@ -426,18 +430,12 @@ export default class CreateMergeRequestDropdown {
         this.refIsValid = true;
         this.refInput.dataset.value = ref;
         this.showAvailableMessage('ref');
-        this.createBranchPath = this.createBranchPath.replace(this.regexps.ref.createBranchPath,
-          pathReplacement);
-        this.createMrPath = this.createMrPath.replace(this.regexps.ref.createMrPath,
-          pathReplacement);
+        this.updateCreatePaths(target, ref);
       }
     } else if (target === 'branch') {
       this.branchIsValid = true;
       this.showAvailableMessage('branch');
-      this.createBranchPath = this.createBranchPath.replace(this.regexps.branch.createBranchPath,
-        pathReplacement);
-      this.createMrPath = this.createMrPath.replace(this.regexps.branch.createMrPath,
-        pathReplacement);
+      this.updateCreatePaths(target, ref);
     } else {
       this.refIsValid = false;
       this.refInput.dataset.value = ref;
@@ -457,4 +455,15 @@ export default class CreateMergeRequestDropdown {
       this.disableCreateAction();
     }
   }
+
+  // target - 'branch' or 'ref'
+  // ref - string - the new value to use as branch or ref
+  updateCreatePaths(target, ref) {
+    const pathReplacement = `$1${ref}`;
+
+    this.createBranchPath = this.createBranchPath.replace(this.regexps[target].createBranchPath,
+      pathReplacement);
+    this.createMrPath = this.createMrPath.replace(this.regexps[target].createMrPath,
+      pathReplacement);
+  }
 }
diff --git a/app/assets/javascripts/due_date_select.js b/app/assets/javascripts/due_date_select.js
index 842a4255f08..4164149dd06 100644
--- a/app/assets/javascripts/due_date_select.js
+++ b/app/assets/javascripts/due_date_select.js
@@ -2,7 +2,9 @@
 
 import $ from 'jquery';
 import Pikaday from 'pikaday';
+import { __ } from '~/locale';
 import axios from './lib/utils/axios_utils';
+import { timeFor } from './lib/utils/datetime_utility';
 import { parsePikadayDate, pikadayToString } from './lib/utils/datefix';
 
 class DueDateSelect {
@@ -14,6 +16,7 @@ class DueDateSelect {
     this.$dropdownParent = $dropdownParent;
     this.$datePicker = $dropdownParent.find('.js-due-date-calendar');
     this.$block = $block;
+    this.$sidebarCollapsedValue = $block.find('.sidebar-collapsed-icon');
     this.$selectbox = $dropdown.closest('.selectbox');
     this.$value = $block.find('.value');
     this.$valueContent = $block.find('.value-content');
@@ -128,7 +131,8 @@ class DueDateSelect {
 
   submitSelectedDate(isDropdown) {
     const selectedDateValue = this.datePayload[this.abilityName].due_date;
-    const displayedDateStyle = this.displayedDate !== 'No due date' ? 'bold' : 'no-value';
+    const hasDueDate = this.displayedDate !== 'No due date';
+    const displayedDateStyle = hasDueDate ? 'bold' : 'no-value';
 
     this.$loading.removeClass('hidden').fadeIn();
 
@@ -145,10 +149,13 @@ class DueDateSelect {
 
     return axios.put(this.issueUpdateURL, this.datePayload)
       .then(() => {
+        const tooltipText = hasDueDate ? `${__('Due date')}<br />${selectedDateValue} (${timeFor(selectedDateValue)})` : __('Due date');
         if (isDropdown) {
           this.$dropdown.trigger('loaded.gl.dropdown');
           this.$dropdown.dropdown('toggle');
         }
+        this.$sidebarCollapsedValue.attr('data-original-title', tooltipText);
+
         return this.$loading.fadeOut();
       });
   }
diff --git a/app/assets/javascripts/ide/components/changed_file_icon.vue b/app/assets/javascripts/ide/components/changed_file_icon.vue
index 037e3efb4ce..1fc11c84639 100644
--- a/app/assets/javascripts/ide/components/changed_file_icon.vue
+++ b/app/assets/javascripts/ide/components/changed_file_icon.vue
@@ -1,31 +1,87 @@
 <script>
-import icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+import Icon from '~/vue_shared/components/icon.vue';
+import { pluralize } from '~/lib/utils/text_utility';
+import { __, sprintf } from '~/locale';
 
 export default {
   components: {
-    icon,
+    Icon,
+  },
+  directives: {
+    tooltip,
   },
   props: {
     file: {
       type: Object,
       required: true,
     },
+    showTooltip: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    showStagedIcon: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
   },
   computed: {
     changedIcon() {
-      return this.file.tempFile ? 'file-addition' : 'file-modified';
+      const suffix = this.file.staged && !this.showStagedIcon ? '-solid' : '';
+      return this.file.tempFile ? `file-addition${suffix}` : `file-modified${suffix}`;
+    },
+    stagedIcon() {
+      return `${this.changedIcon}-solid`;
     },
     changedIconClass() {
-      return `multi-${this.changedIcon}`;
+      return `multi-${this.changedIcon} prepend-left-5 pull-left`;
+    },
+    tooltipTitle() {
+      if (!this.showTooltip) return undefined;
+
+      const type = this.file.tempFile ? 'addition' : 'modification';
+
+      if (this.file.changed && !this.file.staged) {
+        return sprintf(__('Unstaged %{type}'), {
+          type,
+        });
+      } else if (!this.file.changed && this.file.staged) {
+        return sprintf(__('Staged %{type}'), {
+          type,
+        });
+      } else if (this.file.changed && this.file.staged) {
+        return sprintf(__('Unstaged and staged %{type}'), {
+          type: pluralize(type),
+        });
+      }
+
+      return undefined;
     },
   },
 };
 </script>
 
 <template>
-  <icon
-    :name="changedIcon"
-    :size="12"
-    :css-classes="`ide-file-changed-icon ${changedIconClass}`"
-  />
+  <span
+    v-tooltip
+    :title="tooltipTitle"
+    data-container="body"
+    data-placement="right"
+    class="ide-file-changed-icon"
+  >
+    <icon
+      v-if="file.staged && showStagedIcon"
+      :name="stagedIcon"
+      :size="12"
+      :css-classes="changedIconClass"
+    />
+    <icon
+      v-if="file.changed || file.tempFile || (file.staged && !showStagedIcon)"
+      :name="changedIcon"
+      :size="12"
+      :css-classes="changedIconClass"
+    />
+  </span>
 </template>
diff --git a/app/assets/javascripts/ide/components/commit_sidebar/empty_state.vue b/app/assets/javascripts/ide/components/commit_sidebar/empty_state.vue
new file mode 100644
index 00000000000..6424b93ce54
--- /dev/null
+++ b/app/assets/javascripts/ide/components/commit_sidebar/empty_state.vue
@@ -0,0 +1,93 @@
+<script>
+import { mapActions, mapState, mapGetters } from 'vuex';
+import Icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+
+export default {
+  components: {
+    Icon,
+  },
+  directives: {
+    tooltip,
+  },
+  props: {
+    noChangesStateSvgPath: {
+      type: String,
+      required: true,
+    },
+    committedStateSvgPath: {
+      type: String,
+      required: true,
+    },
+  },
+  computed: {
+    ...mapState(['lastCommitMsg', 'rightPanelCollapsed']),
+    ...mapGetters(['collapseButtonIcon', 'collapseButtonTooltip']),
+    statusSvg() {
+      return this.lastCommitMsg ? this.committedStateSvgPath : this.noChangesStateSvgPath;
+    },
+  },
+  methods: {
+    ...mapActions(['toggleRightPanelCollapsed']),
+  },
+};
+</script>
+
+<template>
+  <div
+    class="multi-file-commit-panel-section ide-commit-empty-state js-empty-state"
+  >
+    <header
+      class="multi-file-commit-panel-header"
+      :class="{
+        'is-collapsed': rightPanelCollapsed,
+      }"
+    >
+      <button
+        v-tooltip
+        :title="collapseButtonTooltip"
+        data-container="body"
+        data-placement="left"
+        type="button"
+        class="btn btn-transparent multi-file-commit-panel-collapse-btn"
+        :aria-label="__('Toggle sidebar')"
+        @click.stop="toggleRightPanelCollapsed"
+      >
+        <icon
+          :name="collapseButtonIcon"
+          :size="18"
+        />
+      </button>
+    </header>
+    <div
+      class="ide-commit-empty-state-container"
+      v-if="!rightPanelCollapsed"
+    >
+      <div class="svg-content svg-80">
+        <img :src="statusSvg" />
+      </div>
+      <div class="append-right-default prepend-left-default">
+        <div
+          class="text-content text-center"
+          v-if="!lastCommitMsg"
+        >
+          <h4>
+            {{ __('No changes') }}
+          </h4>
+          <p>
+            {{ __('Edit files in the editor and commit changes here') }}
+          </p>
+        </div>
+        <div
+          class="text-content text-center"
+          v-else
+        >
+          <h4>
+            {{ __('All changes are committed') }}
+          </h4>
+          <p v-html="lastCommitMsg"></p>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>
diff --git a/app/assets/javascripts/ide/components/commit_sidebar/list.vue b/app/assets/javascripts/ide/components/commit_sidebar/list.vue
index 453208f3f19..ff05ee8682a 100644
--- a/app/assets/javascripts/ide/components/commit_sidebar/list.vue
+++ b/app/assets/javascripts/ide/components/commit_sidebar/list.vue
@@ -1,56 +1,132 @@
 <script>
-  import { mapState } from 'vuex';
-  import icon from '~/vue_shared/components/icon.vue';
-  import listItem from './list_item.vue';
-  import listCollapsed from './list_collapsed.vue';
+import { mapActions, mapState, mapGetters } from 'vuex';
+import { __, sprintf } from '~/locale';
+import Icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+import ListItem from './list_item.vue';
+import ListCollapsed from './list_collapsed.vue';
 
-  export default {
-    components: {
-      icon,
-      listItem,
-      listCollapsed,
+export default {
+  components: {
+    Icon,
+    ListItem,
+    ListCollapsed,
+  },
+  directives: {
+    tooltip,
+  },
+  props: {
+    title: {
+      type: String,
+      required: true,
     },
-    props: {
-      title: {
-        type: String,
-        required: true,
-      },
-      fileList: {
-        type: Array,
-        required: true,
-      },
+    fileList: {
+      type: Array,
+      required: true,
     },
-    computed: {
-      ...mapState([
-        'currentProjectId',
-        'currentBranchId',
-        'rightPanelCollapsed',
-      ]),
-      isCommitInfoShown() {
-        return this.rightPanelCollapsed || this.fileList.length;
-      },
+    showToggle: {
+      type: Boolean,
+      required: false,
+      default: true,
     },
-    methods: {
-      toggleCollapsed() {
-        this.$emit('toggleCollapsed');
-      },
+    iconName: {
+      type: String,
+      required: true,
     },
-  };
+    action: {
+      type: String,
+      required: true,
+    },
+    actionBtnText: {
+      type: String,
+      required: true,
+    },
+    itemActionComponent: {
+      type: String,
+      required: true,
+    },
+    stagedList: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  computed: {
+    ...mapState(['rightPanelCollapsed']),
+    ...mapGetters(['collapseButtonIcon', 'collapseButtonTooltip']),
+    titleText() {
+      return sprintf(__('%{title} changes'), {
+        title: this.title,
+      });
+    },
+  },
+  methods: {
+    ...mapActions(['toggleRightPanelCollapsed', 'stageAllChanges', 'unstageAllChanges']),
+    actionBtnClicked() {
+      this[this.action]();
+    },
+  },
+};
 </script>
 
 <template>
   <div
+    class="ide-commit-list-container"
     :class="{
-      'multi-file-commit-list': isCommitInfoShown
+      'is-collapsed': rightPanelCollapsed,
     }"
   >
+    <header
+      class="multi-file-commit-panel-header"
+    >
+      <div
+        v-if="!rightPanelCollapsed"
+        class="multi-file-commit-panel-header-title"
+        :class="{
+          'append-right-10': showToggle,
+        }"
+      >
+        <icon
+          v-once
+          :name="iconName"
+          :size="18"
+        />
+        {{ titleText }}
+        <button
+          type="button"
+          class="btn btn-blank btn-link ide-staged-action-btn"
+          @click="actionBtnClicked"
+        >
+          {{ actionBtnText }}
+        </button>
+      </div>
+      <button
+        v-if="showToggle"
+        v-tooltip
+        :title="collapseButtonTooltip"
+        data-container="body"
+        data-placement="left"
+        type="button"
+        class="btn btn-transparent multi-file-commit-panel-collapse-btn"
+        :aria-label="__('Toggle sidebar')"
+        @click.stop="toggleRightPanelCollapsed"
+      >
+        <icon
+          :name="collapseButtonIcon"
+          :size="18"
+        />
+      </button>
+    </header>
     <list-collapsed
       v-if="rightPanelCollapsed"
+      :files="fileList"
+      :icon-name="iconName"
+      :title="title"
     />
     <template v-else>
       <ul
         v-if="fileList.length"
-        class="list-unstyled append-bottom-0"
+        class="multi-file-commit-list list-unstyled append-bottom-0"
       >
         <li
           v-for="file in fileList"
@@ -58,9 +134,18 @@
         >
           <list-item
             :file="file"
+            :action-component="itemActionComponent"
+            :key-prefix="title"
+            :staged-list="stagedList"
           />
         </li>
       </ul>
+      <p
+        v-else
+        class="multi-file-commit-list help-block"
+      >
+        {{ __('No changes') }}
+      </p>
     </template>
   </div>
 </template>
diff --git a/app/assets/javascripts/ide/components/commit_sidebar/list_collapsed.vue b/app/assets/javascripts/ide/components/commit_sidebar/list_collapsed.vue
index 15918ac9631..2254271c679 100644
--- a/app/assets/javascripts/ide/components/commit_sidebar/list_collapsed.vue
+++ b/app/assets/javascripts/ide/components/commit_sidebar/list_collapsed.vue
@@ -1,35 +1,110 @@
 <script>
-  import { mapGetters } from 'vuex';
-  import icon from '~/vue_shared/components/icon.vue';
+import Icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+import { sprintf, n__, __ } from '~/locale';
 
-  export default {
-    components: {
-      icon,
+export default {
+  components: {
+    Icon,
+  },
+  directives: {
+    tooltip,
+  },
+  props: {
+    files: {
+      type: Array,
+      required: true,
     },
-    computed: {
-      ...mapGetters([
-        'addedFiles',
-        'modifiedFiles',
-      ]),
+    iconName: {
+      type: String,
+      required: true,
     },
-  };
+    title: {
+      type: String,
+      required: true,
+    },
+  },
+  computed: {
+    addedFilesLength() {
+      return this.files.filter(f => f.tempFile).length;
+    },
+    modifiedFilesLength() {
+      return this.files.filter(f => !f.tempFile).length;
+    },
+    addedFilesIconClass() {
+      return this.addedFilesLength ? 'multi-file-addition' : '';
+    },
+    modifiedFilesClass() {
+      return this.modifiedFilesLength ? 'multi-file-modified' : '';
+    },
+    additionsTooltip() {
+      return sprintf(n__('1 %{type} addition', '%d %{type} additions', this.addedFilesLength), {
+        type: this.title.toLowerCase(),
+      });
+    },
+    modifiedTooltip() {
+      return sprintf(
+        n__('1 %{type} modification', '%d %{type} modifications', this.modifiedFilesLength),
+        { type: this.title.toLowerCase() },
+      );
+    },
+    titleTooltip() {
+      return sprintf(__('%{title} changes'), { title: this.title });
+    },
+    additionIconName() {
+      return this.title.toLowerCase() === 'staged' ? 'file-addition-solid' : 'file-addition';
+    },
+    modifiedIconName() {
+      return this.title.toLowerCase() === 'staged' ? 'file-modified-solid' : 'file-modified';
+    },
+  },
+};
 </script>
 
 <template>
   <div
     class="multi-file-commit-list-collapsed text-center"
   >
-    <icon
-      name="file-addition"
-      :size="18"
-      css-classes="multi-file-addition append-bottom-10"
-    />
-    {{ addedFiles.length }}
-    <icon
-      name="file-modified"
-      :size="18"
-      css-classes="multi-file-modified prepend-top-10 append-bottom-10"
-    />
-    {{ modifiedFiles.length }}
+    <div
+      v-tooltip
+      :title="titleTooltip"
+      data-container="body"
+      data-placement="left"
+      class="append-bottom-15"
+    >
+      <icon
+        v-once
+        :name="iconName"
+        :size="18"
+      />
+    </div>
+    <div
+      v-tooltip
+      :title="additionsTooltip"
+      data-container="body"
+      data-placement="left"
+      class="append-bottom-10"
+    >
+      <icon
+        :name="additionIconName"
+        :size="18"
+        :css-classes="addedFilesIconClass"
+      />
+    </div>
+    {{ addedFilesLength }}
+    <div
+      v-tooltip
+      :title="modifiedTooltip"
+      data-container="body"
+      data-placement="left"
+      class="prepend-top-10 append-bottom-10"
+    >
+      <icon
+        :name="modifiedIconName"
+        :size="18"
+        :css-classes="modifiedFilesClass"
+      />
+    </div>
+    {{ modifiedFilesLength }}
   </div>
 </template>
diff --git a/app/assets/javascripts/ide/components/commit_sidebar/list_item.vue b/app/assets/javascripts/ide/components/commit_sidebar/list_item.vue
index 560cdd941cd..ad4713c40d5 100644
--- a/app/assets/javascripts/ide/components/commit_sidebar/list_item.vue
+++ b/app/assets/javascripts/ide/components/commit_sidebar/list_item.vue
@@ -1,34 +1,69 @@
 <script>
 import { mapActions } from 'vuex';
 import Icon from '~/vue_shared/components/icon.vue';
+import StageButton from './stage_button.vue';
+import UnstageButton from './unstage_button.vue';
 
 export default {
   components: {
     Icon,
+    StageButton,
+    UnstageButton,
   },
   props: {
     file: {
       type: Object,
       required: true,
     },
+    actionComponent: {
+      type: String,
+      required: true,
+    },
+    keyPrefix: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    stagedList: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
   },
   computed: {
     iconName() {
-      return this.file.tempFile ? 'file-addition' : 'file-modified';
+      const prefix = this.stagedList ? '-solid' : '';
+      return this.file.tempFile ? `file-addition${prefix}` : `file-modified${prefix}`;
     },
     iconClass() {
-      return `multi-file-${this.file.tempFile ? 'addition' : 'modified'} append-right-8`;
+      return `multi-file-${this.file.tempFile ? 'additions' : 'modified'} append-right-8`;
     },
   },
   methods: {
-    ...mapActions(['discardFileChanges', 'updateViewer', 'openPendingTab']),
-    openFileInEditor(file) {
-      return this.openPendingTab(file).then(changeViewer => {
+    ...mapActions([
+      'discardFileChanges',
+      'updateViewer',
+      'openPendingTab',
+      'unstageChange',
+      'stageChange',
+    ]),
+    openFileInEditor() {
+      return this.openPendingTab({
+        file: this.file,
+        keyPrefix: this.keyPrefix.toLowerCase(),
+      }).then(changeViewer => {
         if (changeViewer) {
           this.updateViewer('diff');
         }
       });
     },
+    fileAction() {
+      if (this.file.staged) {
+        this.unstageChange(this.file.path);
+      } else {
+        this.stageChange(this.file.path);
+      }
+    },
   },
 };
 </script>
@@ -38,7 +73,9 @@ export default {
     <button
       type="button"
       class="multi-file-commit-list-path"
-      @click="openFileInEditor(file)">
+      @dblclick="fileAction"
+      @click="openFileInEditor"
+    >
       <span class="multi-file-commit-list-file-path">
         <icon
           :name="iconName"
@@ -47,12 +84,9 @@ export default {
         />{{ file.path }}
       </span>
     </button>
-    <button
-      type="button"
-      class="btn btn-blank multi-file-discard-btn"
-      @click="discardFileChanges(file.path)"
-    >
-      Discard
-    </button>
+    <component
+      :is="actionComponent"
+      :path="file.path"
+    />
   </div>
 </template>
diff --git a/app/assets/javascripts/ide/components/commit_sidebar/stage_button.vue b/app/assets/javascripts/ide/components/commit_sidebar/stage_button.vue
new file mode 100644
index 00000000000..52dce8412ab
--- /dev/null
+++ b/app/assets/javascripts/ide/components/commit_sidebar/stage_button.vue
@@ -0,0 +1,59 @@
+<script>
+import { mapActions } from 'vuex';
+import Icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+
+export default {
+  components: {
+    Icon,
+  },
+  directives: {
+    tooltip,
+  },
+  props: {
+    path: {
+      type: String,
+      required: true,
+    },
+  },
+  methods: {
+    ...mapActions(['stageChange', 'discardFileChanges']),
+  },
+};
+</script>
+
+<template>
+  <div
+    v-once
+    class="multi-file-discard-btn"
+  >
+    <button
+      v-tooltip
+      type="button"
+      class="btn btn-blank append-right-5"
+      :aria-label="__('Stage changes')"
+      :title="__('Stage changes')"
+      data-container="body"
+      @click.stop="stageChange(path)"
+    >
+      <icon
+        name="mobile-issue-close"
+        :size="12"
+      />
+    </button>
+    <button
+      v-tooltip
+      type="button"
+      class="btn btn-blank"
+      :aria-label="__('Discard changes')"
+      :title="__('Discard changes')"
+      data-container="body"
+      @click.stop="discardFileChanges(path)"
+    >
+      <icon
+        name="remove"
+        :size="12"
+      />
+    </button>
+  </div>
+</template>
diff --git a/app/assets/javascripts/ide/components/commit_sidebar/unstage_button.vue b/app/assets/javascripts/ide/components/commit_sidebar/unstage_button.vue
new file mode 100644
index 00000000000..123d60da47e
--- /dev/null
+++ b/app/assets/javascripts/ide/components/commit_sidebar/unstage_button.vue
@@ -0,0 +1,45 @@
+<script>
+import { mapActions } from 'vuex';
+import Icon from '~/vue_shared/components/icon.vue';
+import tooltip from '~/vue_shared/directives/tooltip';
+
+export default {
+  components: {
+    Icon,
+  },
+  directives: {
+    tooltip,
+  },
+  props: {
+    path: {
+      type: String,
+      required: true,
+    },
+  },
+  methods: {
+    ...mapActions(['unstageChange']),
+  },
+};
+</script>
+
+<template>
+  <div
+    v-once
+    class="multi-file-discard-btn"
+  >
+    <button
+      v-tooltip
+      type="button"
+      class="btn btn-blank"
+      :aria-label="__('Unstage changes')"
+      :title="__('Unstage changes')"
+      data-container="body"
+      @click="unstageChange(path)"
+    >
+      <icon
+        name="history"
+        :size="12"
+      />
+    </button>
+  </div>
+</template>
diff --git a/app/assets/javascripts/ide/components/ide_context_bar.vue b/app/assets/javascripts/ide/components/ide_context_bar.vue
index 79a83b47994..627fbeb9adf 100644
--- a/app/assets/javascripts/ide/components/ide_context_bar.vue
+++ b/app/assets/javascripts/ide/components/ide_context_bar.vue
@@ -1,5 +1,4 @@
 <script>
-import { mapActions, mapGetters, mapState } from 'vuex';
 import icon from '~/vue_shared/components/icon.vue';
 import panelResizer from '~/vue_shared/components/panel_resizer.vue';
 import repoCommitSection from './repo_commit_section.vue';
@@ -22,13 +21,6 @@ export default {
       required: true,
     },
   },
-  computed: {
-    ...mapState(['changedFiles', 'rightPanelCollapsed']),
-    ...mapGetters(['currentIcon']),
-  },
-  methods: {
-    ...mapActions(['setPanelCollapsedStatus']),
-  },
 };
 </script>
 
@@ -41,40 +33,6 @@ export default {
     <div
       class="multi-file-commit-panel-section"
     >
-      <header
-        class="multi-file-commit-panel-header"
-        :class="{
-          'is-collapsed': rightPanelCollapsed,
-        }"
-      >
-        <div
-          class="multi-file-commit-panel-header-title"
-          v-if="!rightPanelCollapsed"
-        >
-          <div
-            v-if="changedFiles.length"
-          >
-            <icon
-              name="list-bulleted"
-              :size="18"
-            />
-            Staged
-          </div>
-        </div>
-        <button
-          type="button"
-          class="btn btn-transparent multi-file-commit-panel-collapse-btn"
-          @click.stop="setPanelCollapsedStatus({
-            side: 'right',
-            collapsed: !rightPanelCollapsed,
-          })"
-        >
-          <icon
-            :name="currentIcon"
-            :size="18"
-          />
-        </button>
-      </header>
       <repo-commit-section
         :no-changes-state-svg-path="noChangesStateSvgPath"
         :committed-state-svg-path="committedStateSvgPath"
diff --git a/app/assets/javascripts/ide/components/repo_commit_section.vue b/app/assets/javascripts/ide/components/repo_commit_section.vue
index 14673754503..877d1b5e026 100644
--- a/app/assets/javascripts/ide/components/repo_commit_section.vue
+++ b/app/assets/javascripts/ide/components/repo_commit_section.vue
@@ -1,10 +1,11 @@
 <script>
 import { mapState, mapActions, mapGetters } from 'vuex';
 import tooltip from '~/vue_shared/directives/tooltip';
-import icon from '~/vue_shared/components/icon.vue';
+import Icon from '~/vue_shared/components/icon.vue';
 import DeprecatedModal from '~/vue_shared/components/deprecated_modal.vue';
 import LoadingButton from '~/vue_shared/components/loading_button.vue';
-import commitFilesList from './commit_sidebar/list.vue';
+import CommitFilesList from './commit_sidebar/list.vue';
+import EmptyState from './commit_sidebar/empty_state.vue';
 import CommitMessageField from './commit_sidebar/message_field.vue';
 import * as consts from '../stores/modules/commit/constants';
 import Actions from './commit_sidebar/actions.vue';
@@ -12,8 +13,9 @@ import Actions from './commit_sidebar/actions.vue';
 export default {
   components: {
     DeprecatedModal,
-    icon,
-    commitFilesList,
+    Icon,
+    CommitFilesList,
+    EmptyState,
     Actions,
     LoadingButton,
     CommitMessageField,
@@ -32,33 +34,17 @@ export default {
     },
   },
   computed: {
-    ...mapState([
-      'currentProjectId',
-      'currentBranchId',
-      'rightPanelCollapsed',
-      'lastCommitMsg',
-      'changedFiles',
-    ]),
+    ...mapState(['changedFiles', 'stagedFiles', 'rightPanelCollapsed']),
     ...mapState('commit', ['commitMessage', 'submitCommitLoading']),
     ...mapGetters('commit', ['commitButtonDisabled', 'discardDraftButtonDisabled', 'branchName']),
-    statusSvg() {
-      return this.lastCommitMsg ? this.committedStateSvgPath : this.noChangesStateSvgPath;
-    },
   },
   methods: {
-    ...mapActions(['setPanelCollapsedStatus']),
     ...mapActions('commit', [
       'updateCommitMessage',
       'discardDraft',
       'commitChanges',
       'updateCommitAction',
     ]),
-    toggleCollapsed() {
-      this.setPanelCollapsedStatus({
-        side: 'right',
-        collapsed: !this.rightPanelCollapsed,
-      });
-    },
     forceCreateNewBranch() {
       return this.updateCommitAction(consts.COMMIT_TO_NEW_BRANCH).then(() => this.commitChanges());
     },
@@ -69,9 +55,6 @@ export default {
 <template>
   <div
     class="multi-file-commit-panel-section"
-    :class="{
-      'multi-file-commit-empty-state-container': !changedFiles.length
-    }"
   >
     <deprecated-modal
       id="ide-create-branch-modal"
@@ -85,15 +68,27 @@ export default {
           Would you like to create a new branch?`) }}
       </template>
     </deprecated-modal>
-    <commit-files-list
-      title="Staged"
-      :file-list="changedFiles"
-      :collapsed="rightPanelCollapsed"
-      @toggleCollapsed="toggleCollapsed"
-    />
     <template
-      v-if="changedFiles.length"
+      v-if="changedFiles.length || stagedFiles.length"
     >
+      <commit-files-list
+        icon-name="unstaged"
+        :title="__('Unstaged')"
+        :file-list="changedFiles"
+        action="stageAllChanges"
+        :action-btn-text="__('Stage all')"
+        item-action-component="stage-button"
+      />
+      <commit-files-list
+        icon-name="staged"
+        :title="__('Staged')"
+        :file-list="stagedFiles"
+        action="unstageAllChanges"
+        :action-btn-text="__('Unstage all')"
+        item-action-component="unstage-button"
+        :show-toggle="false"
+        :staged-list="true"
+      />
       <form
         class="form-horizontal multi-file-commit-form"
         @submit.prevent.stop="commitChanges"
@@ -123,38 +118,10 @@ export default {
         </div>
       </form>
     </template>
-    <div
-      v-else-if="!rightPanelCollapsed"
-      class="row js-empty-state"
-    >
-      <div class="col-xs-10 col-xs-offset-1">
-        <div class="svg-content svg-80">
-          <img :src="statusSvg" />
-        </div>
-      </div>
-      <div class="col-xs-10 col-xs-offset-1">
-        <div
-          class="text-content text-center"
-          v-if="!lastCommitMsg"
-        >
-          <h4>
-            {{ __('No changes') }}
-          </h4>
-          <p>
-            {{ __('Edit files in the editor and commit changes here') }}
-          </p>
-        </div>
-        <div
-          class="text-content text-center"
-          v-else
-        >
-          <h4>
-            {{ __('All changes are committed') }}
-          </h4>
-          <p v-html="lastCommitMsg">
-          </p>
-        </div>
-      </div>
-    </div>
+    <empty-state
+      v-else
+      :no-changes-state-svg-path="noChangesStateSvgPath"
+      :committed-state-svg-path="committedStateSvgPath"
+    />
   </div>
 </template>
diff --git a/app/assets/javascripts/ide/components/repo_editor.vue b/app/assets/javascripts/ide/components/repo_editor.vue
index 711bafa17a9..3a04cdd8e46 100644
--- a/app/assets/javascripts/ide/components/repo_editor.vue
+++ b/app/assets/javascripts/ide/components/repo_editor.vue
@@ -20,7 +20,7 @@ export default {
   },
   computed: {
     ...mapState(['rightPanelCollapsed', 'viewer', 'delayViewerUpdated', 'panelResizing']),
-    ...mapGetters(['currentMergeRequest']),
+    ...mapGetters(['currentMergeRequest', 'getStagedFile']),
     shouldHideEditor() {
       return this.file && this.file.binary && !this.file.content;
     },
@@ -120,7 +120,12 @@ export default {
     setupEditor() {
       if (!this.file || !this.editor.instance) return;
 
-      this.model = this.editor.createModel(this.file);
+      const head = this.getStagedFile(this.file.path);
+
+      this.model = this.editor.createModel(
+        this.file,
+        this.file.staged && this.file.key.indexOf('unstaged-') === 0 ? head : null,
+      );
 
       if (this.viewer === 'mrdiff') {
         this.editor.attachMergeRequestModel(this.model);
diff --git a/app/assets/javascripts/ide/components/repo_file.vue b/app/assets/javascripts/ide/components/repo_file.vue
index 3b5068d4910..8b18c7d28b4 100644
--- a/app/assets/javascripts/ide/components/repo_file.vue
+++ b/app/assets/javascripts/ide/components/repo_file.vue
@@ -102,8 +102,11 @@ export default {
             v-if="file.mrChange"
           />
           <changed-file-icon
+            v-if="file.changed || file.tempFile || file.staged"
             :file="file"
-            v-if="file.changed || file.tempFile"
+            :show-tooltip="true"
+            :show-staged-icon="true"
+            class="prepend-top-5 pull-right"
           />
         </span>
         <new-dropdown
diff --git a/app/assets/javascripts/ide/components/repo_tab.vue b/app/assets/javascripts/ide/components/repo_tab.vue
index 304a73ed1ad..35a362b01e0 100644
--- a/app/assets/javascripts/ide/components/repo_tab.vue
+++ b/app/assets/javascripts/ide/components/repo_tab.vue
@@ -26,13 +26,16 @@ export default {
   },
   computed: {
     closeLabel() {
-      if (this.tab.changed || this.tab.tempFile) {
+      if (this.fileHasChanged) {
         return `${this.tab.name} changed`;
       }
       return `Close ${this.tab.name}`;
     },
     showChangedIcon() {
-      return this.tab.changed ? !this.tabMouseOver : false;
+      return this.fileHasChanged ? !this.tabMouseOver : false;
+    },
+    fileHasChanged() {
+      return this.tab.changed || this.tab.tempFile || this.tab.staged;
     },
   },
 
@@ -42,18 +45,18 @@ export default {
       this.updateDelayViewerUpdated(true);
 
       if (tab.pending) {
-        this.openPendingTab(tab);
+        this.openPendingTab({ file: tab, keyPrefix: tab.staged ? 'staged' : 'unstaged' });
       } else {
         this.$router.push(`/project${tab.url}`);
       }
     },
     mouseOverTab() {
-      if (this.tab.changed) {
+      if (this.fileHasChanged) {
         this.tabMouseOver = true;
       }
     },
     mouseOutTab() {
-      if (this.tab.changed) {
+      if (this.fileHasChanged) {
         this.tabMouseOver = false;
       }
     },
diff --git a/app/assets/javascripts/ide/lib/common/model.js b/app/assets/javascripts/ide/lib/common/model.js
index e47adae99ed..016dcda1fa1 100644
--- a/app/assets/javascripts/ide/lib/common/model.js
+++ b/app/assets/javascripts/ide/lib/common/model.js
@@ -3,15 +3,16 @@ import Disposable from './disposable';
 import eventHub from '../../eventhub';
 
 export default class Model {
-  constructor(monaco, file) {
+  constructor(monaco, file, head = null) {
     this.monaco = monaco;
     this.disposable = new Disposable();
     this.file = file;
+    this.head = head;
     this.content = file.content !== '' ? file.content : file.raw;
 
     this.disposable.add(
       (this.originalModel = this.monaco.editor.createModel(
-        this.file.raw,
+        head ? head.content : this.file.raw,
         undefined,
         new this.monaco.Uri(null, null, `original/${this.file.key}`),
       )),
@@ -31,13 +32,15 @@ export default class Model {
       );
     }
 
-    this.events = new Map();
+    this.events = new Set();
 
     this.updateContent = this.updateContent.bind(this);
+    this.updateNewContent = this.updateNewContent.bind(this);
     this.dispose = this.dispose.bind(this);
 
     eventHub.$on(`editor.update.model.dispose.${this.file.key}`, this.dispose);
-    eventHub.$on(`editor.update.model.content.${this.file.path}`, this.updateContent);
+    eventHub.$on(`editor.update.model.content.${this.file.key}`, this.updateContent);
+    eventHub.$on(`editor.update.model.new.content.${this.file.key}`, this.updateNewContent);
   }
 
   get url() {
@@ -73,22 +76,36 @@ export default class Model {
   }
 
   onChange(cb) {
-    this.events.set(
-      this.path,
-      this.disposable.add(this.model.onDidChangeContent(e => cb(this, e))),
-    );
+    this.events.add(this.disposable.add(this.model.onDidChangeContent(e => cb(this, e))));
+  }
+
+  onDispose(cb) {
+    this.events.add(cb);
   }
 
-  updateContent(content) {
+  updateContent({ content, changed }) {
     this.getOriginalModel().setValue(content);
+
+    if (!changed) {
+      this.getModel().setValue(content);
+    }
+  }
+
+  updateNewContent(content) {
     this.getModel().setValue(content);
   }
 
   dispose() {
     this.disposable.dispose();
+
+    this.events.forEach(cb => {
+      if (typeof cb === 'function') cb();
+    });
+
     this.events.clear();
 
     eventHub.$off(`editor.update.model.dispose.${this.file.key}`, this.dispose);
-    eventHub.$off(`editor.update.model.content.${this.file.path}`, this.updateContent);
+    eventHub.$off(`editor.update.model.content.${this.file.key}`, this.updateContent);
+    eventHub.$off(`editor.update.model.new.content.${this.file.key}`, this.updateNewContent);
   }
 }
diff --git a/app/assets/javascripts/ide/lib/common/model_manager.js b/app/assets/javascripts/ide/lib/common/model_manager.js
index 0e7b563b5d6..7f643969480 100644
--- a/app/assets/javascripts/ide/lib/common/model_manager.js
+++ b/app/assets/javascripts/ide/lib/common/model_manager.js
@@ -17,12 +17,12 @@ export default class ModelManager {
     return this.models.get(key);
   }
 
-  addModel(file) {
+  addModel(file, head = null) {
     if (this.hasCachedModel(file.key)) {
       return this.getModel(file.key);
     }
 
-    const model = new Model(this.monaco, file);
+    const model = new Model(this.monaco, file, head);
     this.models.set(model.path, model);
     this.disposable.add(model);
 
diff --git a/app/assets/javascripts/ide/lib/decorations/controller.js b/app/assets/javascripts/ide/lib/decorations/controller.js
index 42904774747..13d477bb2cf 100644
--- a/app/assets/javascripts/ide/lib/decorations/controller.js
+++ b/app/assets/javascripts/ide/lib/decorations/controller.js
@@ -38,6 +38,15 @@ export default class DecorationsController {
     );
   }
 
+  hasDecorations(model) {
+    return this.decorations.has(model.url);
+  }
+
+  removeDecorations(model) {
+    this.decorations.delete(model.url);
+    this.editorDecorations.delete(model.url);
+  }
+
   dispose() {
     this.decorations.clear();
     this.editorDecorations.clear();
diff --git a/app/assets/javascripts/ide/lib/diff/controller.js b/app/assets/javascripts/ide/lib/diff/controller.js
index b136545ad11..f579424cf33 100644
--- a/app/assets/javascripts/ide/lib/diff/controller.js
+++ b/app/assets/javascripts/ide/lib/diff/controller.js
@@ -3,7 +3,7 @@ import { throttle } from 'underscore';
 import DirtyDiffWorker from './diff_worker';
 import Disposable from '../common/disposable';
 
-export const getDiffChangeType = (change) => {
+export const getDiffChangeType = change => {
   if (change.modified) {
     return 'modified';
   } else if (change.added) {
@@ -16,12 +16,7 @@ export const getDiffChangeType = (change) => {
 };
 
 export const getDecorator = change => ({
-  range: new monaco.Range(
-    change.lineNumber,
-    1,
-    change.endLineNumber,
-    1,
-  ),
+  range: new monaco.Range(change.lineNumber, 1, change.endLineNumber, 1),
   options: {
     isWholeLine: true,
     linesDecorationsClassName: `dirty-diff dirty-diff-${getDiffChangeType(change)}`,
@@ -31,6 +26,7 @@ export const getDecorator = change => ({
 export default class DirtyDiffController {
   constructor(modelManager, decorationsController) {
     this.disposable = new Disposable();
+    this.models = new Map();
     this.editorSimpleWorker = null;
     this.modelManager = modelManager;
     this.decorationsController = decorationsController;
@@ -42,7 +38,15 @@ export default class DirtyDiffController {
   }
 
   attachModel(model) {
+    if (this.models.has(model.url)) return;
+
     model.onChange(() => this.throttledComputeDiff(model));
+    model.onDispose(() => {
+      this.decorationsController.removeDecorations(model);
+      this.models.delete(model.url);
+    });
+
+    this.models.set(model.url, model);
   }
 
   computeDiff(model) {
@@ -54,7 +58,11 @@ export default class DirtyDiffController {
   }
 
   reDecorate(model) {
-    this.decorationsController.decorate(model);
+    if (this.decorationsController.hasDecorations(model)) {
+      this.decorationsController.decorate(model);
+    } else {
+      this.computeDiff(model);
+    }
   }
 
   decorate({ data }) {
@@ -65,6 +73,7 @@ export default class DirtyDiffController {
 
   dispose() {
     this.disposable.dispose();
+    this.models.clear();
 
     this.dirtyDiffWorker.removeEventListener('message', this.decorate);
     this.dirtyDiffWorker.terminate();
diff --git a/app/assets/javascripts/ide/lib/editor.js b/app/assets/javascripts/ide/lib/editor.js
index 001737d6ee8..2d3ee7d4f48 100644
--- a/app/assets/javascripts/ide/lib/editor.js
+++ b/app/assets/javascripts/ide/lib/editor.js
@@ -77,8 +77,8 @@ export default class Editor {
     }
   }
 
-  createModel(file) {
-    return this.modelManager.addModel(file);
+  createModel(file, head = null) {
+    return this.modelManager.addModel(file, head);
   }
 
   attachModel(model) {
diff --git a/app/assets/javascripts/ide/stores/actions.js b/app/assets/javascripts/ide/stores/actions.js
index c6ba679d99c..cecb4d215ba 100644
--- a/app/assets/javascripts/ide/stores/actions.js
+++ b/app/assets/javascripts/ide/stores/actions.js
@@ -1,3 +1,4 @@
+import $ from 'jquery';
 import Vue from 'vue';
 import { visitUrl } from '~/lib/utils/url_utility';
 import flash from '~/flash';
@@ -32,6 +33,22 @@ export const setPanelCollapsedStatus = ({ commit }, { side, collapsed }) => {
   }
 };
 
+export const toggleRightPanelCollapsed = (
+  { dispatch, state },
+  e = undefined,
+) => {
+  if (e) {
+    $(e.currentTarget)
+      .tooltip('hide')
+      .blur();
+  }
+
+  dispatch('setPanelCollapsedStatus', {
+    side: 'right',
+    collapsed: !state.rightPanelCollapsed,
+  });
+};
+
 export const setResizingStatus = ({ commit }, resizing) => {
   commit(types.SET_RESIZING_STATUS, resizing);
 };
@@ -104,6 +121,14 @@ export const scrollToTab = () => {
   });
 };
 
+export const stageAllChanges = ({ state, commit }) => {
+  state.changedFiles.forEach(file => commit(types.STAGE_CHANGE, file.path));
+};
+
+export const unstageAllChanges = ({ state, commit }) => {
+  state.stagedFiles.forEach(file => commit(types.UNSTAGE_CHANGE, file.path));
+};
+
 export const updateViewer = ({ commit }, viewer) => {
   commit(types.UPDATE_VIEWER, viewer);
 };
diff --git a/app/assets/javascripts/ide/stores/actions/file.js b/app/assets/javascripts/ide/stores/actions/file.js
index 1a17320a1ea..d782e0a84d2 100644
--- a/app/assets/javascripts/ide/stores/actions/file.js
+++ b/app/assets/javascripts/ide/stores/actions/file.js
@@ -24,7 +24,10 @@ export const closeFile = ({ commit, state, dispatch }, file) => {
 
     if (nextFileToOpen.pending) {
       dispatch('updateViewer', 'diff');
-      dispatch('openPendingTab', nextFileToOpen);
+      dispatch('openPendingTab', {
+        file: nextFileToOpen,
+        keyPrefix: nextFileToOpen.staged ? 'staged' : 'unstaged',
+      });
     } else {
       dispatch('updateDelayViewerUpdated', true);
       router.push(`/project${nextFileToOpen.url}`);
@@ -153,7 +156,7 @@ export const setFileViewMode = ({ state, commit }, { file, viewMode }) => {
   commit(types.SET_FILE_VIEWMODE, { file, viewMode });
 };
 
-export const discardFileChanges = ({ state, commit }, path) => {
+export const discardFileChanges = ({ dispatch, state, commit, getters }, path) => {
   const file = state.entries[path];
 
   commit(types.DISCARD_FILE_CHANGES, path);
@@ -161,17 +164,40 @@ export const discardFileChanges = ({ state, commit }, path) => {
 
   if (file.tempFile && file.opened) {
     commit(types.TOGGLE_FILE_OPEN, path);
+  } else if (getters.activeFile && file.path === getters.activeFile.path) {
+    dispatch('updateDelayViewerUpdated', true)
+      .then(() => {
+        router.push(`/project${file.url}`);
+      })
+      .catch(e => {
+        throw e;
+      });
+  }
+
+  eventHub.$emit(`editor.update.model.new.content.${file.key}`, file.content);
+  eventHub.$emit(`editor.update.model.dispose.unstaged-${file.key}`, file.content);
+};
+
+export const stageChange = ({ commit, state }, path) => {
+  const stagedFile = state.stagedFiles.find(f => f.path === path);
+
+  commit(types.STAGE_CHANGE, path);
+
+  if (stagedFile) {
+    eventHub.$emit(`editor.update.model.new.content.staged-${stagedFile.key}`, stagedFile.content);
   }
+};
 
-  eventHub.$emit(`editor.update.model.content.${file.path}`, file.raw);
+export const unstageChange = ({ commit }, path) => {
+  commit(types.UNSTAGE_CHANGE, path);
 };
 
-export const openPendingTab = ({ commit, getters, dispatch, state }, file) => {
-  if (getters.activeFile && getters.activeFile.path === file.path && state.viewer === 'diff') {
+export const openPendingTab = ({ commit, getters, dispatch, state }, { file, keyPrefix }) => {
+  if (getters.activeFile && getters.activeFile === file && state.viewer === 'diff') {
     return false;
   }
 
-  commit(types.ADD_PENDING_TAB, { file });
+  commit(types.ADD_PENDING_TAB, { file, keyPrefix });
 
   dispatch('scrollToTab');
 
diff --git a/app/assets/javascripts/ide/stores/getters.js b/app/assets/javascripts/ide/stores/getters.js
index a77cdbc13c8..8518d2f6f06 100644
--- a/app/assets/javascripts/ide/stores/getters.js
+++ b/app/assets/javascripts/ide/stores/getters.js
@@ -1,3 +1,5 @@
+import { __ } from '~/locale';
+
 export const activeFile = state => state.openFiles.find(file => file.active) || null;
 
 export const addedFiles = state => state.changedFiles.filter(f => f.tempFile);
@@ -29,9 +31,15 @@ export const currentMergeRequest = state => {
 };
 
 // eslint-disable-next-line no-confusing-arrow
-export const currentIcon = state =>
+export const collapseButtonIcon = state =>
   state.rightPanelCollapsed ? 'angle-double-left' : 'angle-double-right';
 
-export const hasChanges = state => !!state.changedFiles.length;
+export const hasChanges = state => !!state.changedFiles.length || !!state.stagedFiles.length;
+
+// eslint-disable-next-line no-confusing-arrow
+export const collapseButtonTooltip = state =>
+  state.rightPanelCollapsed ? __('Expand sidebar') : __('Collapse sidebar');
 
 export const hasMergeRequest = state => !!state.currentMergeRequestId;
+
+export const getStagedFile = state => path => state.stagedFiles.find(f => f.path === path);
diff --git a/app/assets/javascripts/ide/stores/modules/commit/actions.js b/app/assets/javascripts/ide/stores/modules/commit/actions.js
index 367c45f7e2d..b26512e213a 100644
--- a/app/assets/javascripts/ide/stores/modules/commit/actions.js
+++ b/app/assets/javascripts/ide/stores/modules/commit/actions.js
@@ -98,40 +98,25 @@ export const updateFilesAfterCommit = (
     { root: true },
   );
 
-  rootState.changedFiles.forEach(entry => {
-    commit(
-      rootTypes.SET_LAST_COMMIT_DATA,
-      {
-        entry,
-        lastCommit,
-      },
-      { root: true },
-    );
-
-    eventHub.$emit(`editor.update.model.content.${entry.path}`, entry.content);
+  rootState.stagedFiles.forEach(file => {
+    const changedFile = rootState.changedFiles.find(f => f.path === file.path);
 
     commit(
-      rootTypes.SET_FILE_RAW_DATA,
+      rootTypes.UPDATE_FILE_AFTER_COMMIT,
       {
-        file: entry,
-        raw: entry.content,
+        file,
+        lastCommit,
       },
       { root: true },
     );
 
-    commit(
-      rootTypes.TOGGLE_FILE_CHANGED,
-      {
-        file: entry,
-        changed: false,
-      },
-      { root: true },
-    );
+    eventHub.$emit(`editor.update.model.content.${file.key}`, {
+      content: file.content,
+      changed: !!changedFile,
+    });
   });
 
-  commit(rootTypes.REMOVE_ALL_CHANGES_FILES, null, { root: true });
-
-  if (state.commitAction === consts.COMMIT_TO_NEW_BRANCH) {
+  if (state.commitAction === consts.COMMIT_TO_NEW_BRANCH && rootGetters.activeFile) {
     router.push(
       `/project/${rootState.currentProjectId}/blob/${branch}/${rootGetters.activeFile.path}`,
     );
@@ -184,6 +169,8 @@ export const commitChanges = ({ commit, state, getters, dispatch, rootState }) =
               { root: true },
             );
           }
+
+          commit(rootTypes.CLEAR_STAGED_CHANGES, null, { root: true });
         })
         .then(() => dispatch('updateCommitAction', consts.COMMIT_TO_CURRENT_BRANCH));
     })
diff --git a/app/assets/javascripts/ide/stores/modules/commit/getters.js b/app/assets/javascripts/ide/stores/modules/commit/getters.js
index f7cdd6adb0c..9c3905a0b0d 100644
--- a/app/assets/javascripts/ide/stores/modules/commit/getters.js
+++ b/app/assets/javascripts/ide/stores/modules/commit/getters.js
@@ -1,12 +1,17 @@
 import * as consts from './constants';
 
-export const discardDraftButtonDisabled = state => state.commitMessage === '' || state.submitCommitLoading;
+const BRANCH_SUFFIX_COUNT = 5;
+
+export const discardDraftButtonDisabled = state =>
+  state.commitMessage === '' || state.submitCommitLoading;
 
 export const commitButtonDisabled = (state, getters, rootState) =>
-  getters.discardDraftButtonDisabled || !rootState.changedFiles.length;
+  getters.discardDraftButtonDisabled || !rootState.stagedFiles.length;
 
 export const newBranchName = (state, _, rootState) =>
-  `${gon.current_username}-${rootState.currentBranchId}-patch-${`${new Date().getTime()}`.substr(-5)}`;
+  `${gon.current_username}-${rootState.currentBranchId}-patch-${`${new Date().getTime()}`.substr(
+    -BRANCH_SUFFIX_COUNT,
+  )}`;
 
 export const branchName = (state, getters, rootState) => {
   if (
diff --git a/app/assets/javascripts/ide/stores/mutation_types.js b/app/assets/javascripts/ide/stores/mutation_types.js
index e3f504e5ab0..f5f95b755c8 100644
--- a/app/assets/javascripts/ide/stores/mutation_types.js
+++ b/app/assets/javascripts/ide/stores/mutation_types.js
@@ -51,5 +51,10 @@ export const SET_FILE_MERGE_REQUEST_CHANGE = 'SET_FILE_MERGE_REQUEST_CHANGE';
 export const UPDATE_VIEWER = 'UPDATE_VIEWER';
 export const UPDATE_DELAY_VIEWER_CHANGE = 'UPDATE_DELAY_VIEWER_CHANGE';
 
+export const CLEAR_STAGED_CHANGES = 'CLEAR_STAGED_CHANGES';
+export const STAGE_CHANGE = 'STAGE_CHANGE';
+export const UNSTAGE_CHANGE = 'UNSTAGE_CHANGE';
+
+export const UPDATE_FILE_AFTER_COMMIT = 'UPDATE_FILE_AFTER_COMMIT';
 export const ADD_PENDING_TAB = 'ADD_PENDING_TAB';
 export const REMOVE_PENDING_TAB = 'REMOVE_PENDING_TAB';
diff --git a/app/assets/javascripts/ide/stores/mutations.js b/app/assets/javascripts/ide/stores/mutations.js
index 5e5eb831662..fbe342f9126 100644
--- a/app/assets/javascripts/ide/stores/mutations.js
+++ b/app/assets/javascripts/ide/stores/mutations.js
@@ -49,6 +49,11 @@ export default {
       lastCommitMsg,
     });
   },
+  [types.CLEAR_STAGED_CHANGES](state) {
+    Object.assign(state, {
+      stagedFiles: [],
+    });
+  },
   [types.SET_ENTRIES](state, entries) {
     Object.assign(state, {
       entries,
@@ -95,6 +100,22 @@ export default {
       delayViewerUpdated,
     });
   },
+  [types.UPDATE_FILE_AFTER_COMMIT](state, { file, lastCommit }) {
+    const changedFile = state.changedFiles.find(f => f.path === file.path);
+
+    Object.assign(state.entries[file.path], {
+      raw: file.content,
+      changed: !!changedFile,
+      staged: false,
+      lastCommit: Object.assign(state.entries[file.path].lastCommit, {
+        id: lastCommit.commit.id,
+        url: lastCommit.commit_path,
+        message: lastCommit.commit.message,
+        author: lastCommit.commit.author_name,
+        updatedAt: lastCommit.commit.authored_date,
+      }),
+    });
+  },
   ...projectMutations,
   ...mergeRequestMutation,
   ...fileMutations,
diff --git a/app/assets/javascripts/ide/stores/mutations/file.js b/app/assets/javascripts/ide/stores/mutations/file.js
index eeb14b5490c..dd7dcba8ac7 100644
--- a/app/assets/javascripts/ide/stores/mutations/file.js
+++ b/app/assets/javascripts/ide/stores/mutations/file.js
@@ -57,7 +57,9 @@ export default {
     });
   },
   [types.UPDATE_FILE_CONTENT](state, { path, content }) {
-    const changed = content !== state.entries[path].raw;
+    const stagedFile = state.stagedFiles.find(f => f.path === path);
+    const rawContent = stagedFile ? stagedFile.content : state.entries[path].raw;
+    const changed = content !== rawContent;
 
     Object.assign(state.entries[path], {
       content,
@@ -91,8 +93,10 @@ export default {
     });
   },
   [types.DISCARD_FILE_CHANGES](state, path) {
+    const stagedFile = state.stagedFiles.find(f => f.path === path);
+
     Object.assign(state.entries[path], {
-      content: state.entries[path].raw,
+      content: stagedFile ? stagedFile.content : state.entries[path].raw,
       changed: false,
     });
   },
@@ -106,16 +110,67 @@ export default {
       changedFiles: state.changedFiles.filter(f => f.path !== path),
     });
   },
+  [types.STAGE_CHANGE](state, path) {
+    const stagedFile = state.stagedFiles.find(f => f.path === path);
+
+    Object.assign(state, {
+      changedFiles: state.changedFiles.filter(f => f.path !== path),
+      entries: Object.assign(state.entries, {
+        [path]: Object.assign(state.entries[path], {
+          staged: true,
+          changed: false,
+        }),
+      }),
+    });
+
+    if (stagedFile) {
+      Object.assign(stagedFile, {
+        ...state.entries[path],
+      });
+    } else {
+      Object.assign(state, {
+        stagedFiles: state.stagedFiles.concat({
+          ...state.entries[path],
+        }),
+      });
+    }
+  },
+  [types.UNSTAGE_CHANGE](state, path) {
+    const changedFile = state.changedFiles.find(f => f.path === path);
+    const stagedFile = state.stagedFiles.find(f => f.path === path);
+
+    if (!changedFile && stagedFile) {
+      Object.assign(state.entries[path], {
+        ...stagedFile,
+        key: state.entries[path].key,
+        active: state.entries[path].active,
+        opened: state.entries[path].opened,
+        changed: true,
+      });
+
+      Object.assign(state, {
+        changedFiles: state.changedFiles.concat(state.entries[path]),
+      });
+    }
+
+    Object.assign(state, {
+      stagedFiles: state.stagedFiles.filter(f => f.path !== path),
+      entries: Object.assign(state.entries, {
+        [path]: Object.assign(state.entries[path], {
+          staged: false,
+        }),
+      }),
+    });
+  },
   [types.TOGGLE_FILE_CHANGED](state, { file, changed }) {
     Object.assign(state.entries[file.path], {
       changed,
     });
   },
   [types.ADD_PENDING_TAB](state, { file, keyPrefix = 'pending' }) {
-    const pendingTab = state.openFiles.find(f => f.path === file.path && f.pending);
-    let openFiles = state.openFiles.map(f =>
-      Object.assign(f, { active: f.path === file.path, opened: false }),
-    );
+    const key = `${keyPrefix}-${file.key}`;
+    const pendingTab = state.openFiles.find(f => f.key === key && f.pending);
+    let openFiles = state.openFiles.map(f => Object.assign(f, { active: false, opened: false }));
 
     if (!pendingTab) {
       const openFile = openFiles.find(f => f.path === file.path);
@@ -126,10 +181,11 @@ export default {
         if (f.path === file.path) {
           return acc.concat({
             ...f,
+            content: file.content,
             active: true,
             pending: true,
             opened: true,
-            key: `${keyPrefix}-${f.key}`,
+            key,
           });
         }
 
diff --git a/app/assets/javascripts/ide/stores/state.js b/app/assets/javascripts/ide/stores/state.js
index e5cc8814000..34975ac3144 100644
--- a/app/assets/javascripts/ide/stores/state.js
+++ b/app/assets/javascripts/ide/stores/state.js
@@ -3,6 +3,7 @@ export default () => ({
   currentBranchId: '',
   currentMergeRequestId: '',
   changedFiles: [],
+  stagedFiles: [],
   endpoints: {},
   lastCommitMsg: '',
   lastCommitPath: '',
diff --git a/app/assets/javascripts/ide/stores/utils.js b/app/assets/javascripts/ide/stores/utils.js
index 05a019de54f..8a222da14c0 100644
--- a/app/assets/javascripts/ide/stores/utils.js
+++ b/app/assets/javascripts/ide/stores/utils.js
@@ -15,6 +15,7 @@ export const dataStructure = () => ({
   opened: false,
   active: false,
   changed: false,
+  staged: false,
   lastCommitPath: '',
   lastCommit: {
     id: '',
@@ -101,7 +102,7 @@ export const setPageTitle = title => {
 export const createCommitPayload = (branch, newBranch, state, rootState) => ({
   branch,
   commit_message: state.commitMessage,
-  actions: rootState.changedFiles.map(f => ({
+  actions: rootState.stagedFiles.map(f => ({
     action: f.tempFile ? 'create' : 'update',
     file_path: f.path,
     content: f.content,
diff --git a/app/assets/javascripts/labels_select.js b/app/assets/javascripts/labels_select.js
index d0050abb8e9..9b62cfb8206 100644
--- a/app/assets/javascripts/labels_select.js
+++ b/app/assets/javascripts/labels_select.js
@@ -83,7 +83,7 @@ export default class LabelsSelect {
         $dropdown.trigger('loading.gl.dropdown');
         axios.put(issueUpdateURL, data)
           .then(({ data }) => {
-            var labelCount, template, labelTooltipTitle, labelTitles;
+            var labelCount, template, labelTooltipTitle, labelTitles, formattedLabels;
             $loading.fadeOut();
             $dropdown.trigger('loaded.gl.dropdown');
             $selectbox.hide();
@@ -115,8 +115,7 @@ export default class LabelsSelect {
               labelTooltipTitle = labelTitles.join(', ');
             }
             else {
-              labelTooltipTitle = '';
-              $sidebarLabelTooltip.tooltip('destroy');
+              labelTooltipTitle = __('Labels');
             }
 
             $sidebarLabelTooltip
diff --git a/app/assets/javascripts/milestone_select.js b/app/assets/javascripts/milestone_select.js
index d0a2b27b0e6..7e9a50a885d 100644
--- a/app/assets/javascripts/milestone_select.js
+++ b/app/assets/javascripts/milestone_select.js
@@ -4,6 +4,7 @@
 
 import $ from 'jquery';
 import _ from 'underscore';
+import { __ } from '~/locale';
 import axios from './lib/utils/axios_utils';
 import { timeFor } from './lib/utils/datetime_utility';
 import ModalStore from './boards/stores/modal_store';
@@ -25,7 +26,7 @@ export default class MilestoneSelect {
     }
 
     $els.each((i, dropdown) => {
-      let collapsedSidebarLabelTemplate, milestoneLinkNoneTemplate, milestoneLinkTemplate, selectedMilestone, selectedMilestoneDefault;
+      let milestoneLinkNoneTemplate, milestoneLinkTemplate, selectedMilestone, selectedMilestoneDefault;
       const $dropdown = $(dropdown);
       const projectId = $dropdown.data('projectId');
       const milestonesUrl = $dropdown.data('milestones');
@@ -52,7 +53,6 @@ export default class MilestoneSelect {
       if (issueUpdateURL) {
         milestoneLinkTemplate = _.template('<a href="/<%- full_path %>/milestones/<%- iid %>" class="bold has-tooltip" data-container="body" title="<%- remaining %>"><%- title %></a>');
         milestoneLinkNoneTemplate = '<span class="no-value">None</span>';
-        collapsedSidebarLabelTemplate = _.template('<span class="has-tooltip" data-container="body" title="<%- name %><br /><%- remaining %>" data-placement="left" data-html="true"> <%- title %> </span>');
       }
       return $dropdown.glDropdown({
         showMenuAbove: showMenuAbove,
@@ -214,10 +214,16 @@ export default class MilestoneSelect {
                   data.milestone.remaining = timeFor(data.milestone.due_date);
                   data.milestone.name = data.milestone.title;
                   $value.html(milestoneLinkTemplate(data.milestone));
-                  return $sidebarCollapsedValue.find('span').html(collapsedSidebarLabelTemplate(data.milestone));
+                  return $sidebarCollapsedValue
+                    .attr('data-original-title', `${data.milestone.name}<br />${data.milestone.remaining}`)
+                    .find('span')
+                    .text(data.milestone.title);
                 } else {
                   $value.html(milestoneLinkNoneTemplate);
-                  return $sidebarCollapsedValue.find('span').text('No');
+                  return $sidebarCollapsedValue
+                    .attr('data-original-title', __('Milestone'))
+                    .find('span')
+                    .text(__('None'));
                 }
               })
               .catch(() => {
diff --git a/app/assets/javascripts/notes.js b/app/assets/javascripts/notes.js
index 2121907dff0..96f2b3eac98 100644
--- a/app/assets/javascripts/notes.js
+++ b/app/assets/javascripts/notes.js
@@ -1427,7 +1427,7 @@ export default class Notes {
     const { discussion_html } = data;
     const lines = $(discussion_html).find('.line_holder');
     lines.addClass('fade-in');
-    $container.find('tbody').prepend(lines);
+    $container.find('.diff-content > table > tbody').prepend(lines);
     const fileHolder = $container.find('.file-holder');
     $container.find('.line-holder-placeholder').remove();
     syntaxHighlight(fileHolder);
diff --git a/app/assets/javascripts/pages/users/activity_calendar.js b/app/assets/javascripts/pages/users/activity_calendar.js
index 8ce938c958b..cbc2d80ee18 100644
--- a/app/assets/javascripts/pages/users/activity_calendar.js
+++ b/app/assets/javascripts/pages/users/activity_calendar.js
@@ -19,7 +19,7 @@ function getSystemDate(systemUtcOffsetSeconds) {
   const date = new Date();
   const localUtcOffsetMinutes = 0 - date.getTimezoneOffset();
   const systemUtcOffsetMinutes = systemUtcOffsetSeconds / 60;
-  date.setMinutes((date.getMinutes() - localUtcOffsetMinutes) + systemUtcOffsetMinutes);
+  date.setMinutes(date.getMinutes() - localUtcOffsetMinutes + systemUtcOffsetMinutes);
   return date;
 }
 
@@ -35,18 +35,36 @@ function formatTooltipText({ date, count }) {
   return `${contribText}<br />${dateDayName} ${dateText}`;
 }
 
-const initColorKey = () => d3.scaleLinear().range(['#acd5f2', '#254e77']).domain([0, 3]);
+const initColorKey = () =>
+  d3
+    .scaleLinear()
+    .range(['#acd5f2', '#254e77'])
+    .domain([0, 3]);
 
 export default class ActivityCalendar {
-  constructor(container, timestamps, calendarActivitiesPath, utcOffset = 0) {
+  constructor(container, timestamps, calendarActivitiesPath, utcOffset = 0, firstDayOfWeek = 0) {
     this.calendarActivitiesPath = calendarActivitiesPath;
     this.clickDay = this.clickDay.bind(this);
     this.currentSelectedDate = '';
     this.daySpace = 1;
     this.daySize = 15;
-    this.daySizeWithSpace = this.daySize + (this.daySpace * 2);
-    this.monthNames = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
+    this.daySizeWithSpace = this.daySize + this.daySpace * 2;
+    this.monthNames = [
+      'Jan',
+      'Feb',
+      'Mar',
+      'Apr',
+      'May',
+      'Jun',
+      'Jul',
+      'Aug',
+      'Sep',
+      'Oct',
+      'Nov',
+      'Dec',
+    ];
     this.months = [];
+    this.firstDayOfWeek = firstDayOfWeek;
 
     // Loop through the timestamps to create a group of objects
     // The group of objects will be grouped based on the day of the week they are
@@ -70,7 +88,7 @@ export default class ActivityCalendar {
 
       // Create a new group array if this is the first day of the week
       // or if is first object
-      if ((day === 0 && i !== 0) || i === 0) {
+      if ((day === this.firstDayOfWeek && i !== 0) || i === 0) {
         this.timestampsTmp.push([]);
         group += 1;
       }
@@ -109,21 +127,30 @@ export default class ActivityCalendar {
   }
 
   renderSvg(container, group) {
-    const width = ((group + 1) * this.daySizeWithSpace) + this.getExtraWidthPadding(group);
-    return d3.select(container)
+    const width = (group + 1) * this.daySizeWithSpace + this.getExtraWidthPadding(group);
+    return d3
+      .select(container)
       .append('svg')
-        .attr('width', width)
-        .attr('height', 167)
-        .attr('class', 'contrib-calendar');
+      .attr('width', width)
+      .attr('height', 167)
+      .attr('class', 'contrib-calendar');
+  }
+
+  dayYPos(day) {
+    return this.daySizeWithSpace * ((day + 7 - this.firstDayOfWeek) % 7);
   }
 
   renderDays() {
-    this.svg.selectAll('g').data(this.timestampsTmp).enter().append('g')
+    this.svg
+      .selectAll('g')
+      .data(this.timestampsTmp)
+      .enter()
+      .append('g')
       .attr('transform', (group, i) => {
         _.each(group, (stamp, a) => {
           if (a === 0 && stamp.day === 0) {
             const month = stamp.date.getMonth();
-            const x = (this.daySizeWithSpace * i) + 1 + this.daySizeWithSpace;
+            const x = this.daySizeWithSpace * i + 1 + this.daySizeWithSpace;
             const lastMonth = _.last(this.months);
             if (
               lastMonth == null ||
@@ -133,86 +160,113 @@ export default class ActivityCalendar {
             }
           }
         });
-        return `translate(${(this.daySizeWithSpace * i) + 1 + this.daySizeWithSpace}, 18)`;
+        return `translate(${this.daySizeWithSpace * i + 1 + this.daySizeWithSpace}, 18)`;
       })
       .selectAll('rect')
-        .data(stamp => stamp)
-        .enter()
-        .append('rect')
-          .attr('x', '0')
-          .attr('y', stamp => this.daySizeWithSpace * stamp.day)
-          .attr('width', this.daySize)
-          .attr('height', this.daySize)
-          .attr('fill', stamp => (
-            stamp.count !== 0 ? this.color(Math.min(stamp.count, 40)) : '#ededed'
-          ))
-          .attr('title', stamp => formatTooltipText(stamp))
-          .attr('class', 'user-contrib-cell js-tooltip')
-          .attr('data-container', 'body')
-          .on('click', this.clickDay);
+      .data(stamp => stamp)
+      .enter()
+      .append('rect')
+      .attr('x', '0')
+      .attr('y', stamp => this.dayYPos(stamp.day))
+      .attr('width', this.daySize)
+      .attr('height', this.daySize)
+      .attr(
+        'fill',
+        stamp => (stamp.count !== 0 ? this.color(Math.min(stamp.count, 40)) : '#ededed'),
+      )
+      .attr('title', stamp => formatTooltipText(stamp))
+      .attr('class', 'user-contrib-cell js-tooltip')
+      .attr('data-container', 'body')
+      .on('click', this.clickDay);
   }
 
   renderDayTitles() {
     const days = [
       {
         text: 'M',
-        y: 29 + (this.daySizeWithSpace * 1),
-      }, {
+        y: 29 + this.dayYPos(1),
+      },
+      {
         text: 'W',
-        y: 29 + (this.daySizeWithSpace * 3),
-      }, {
+        y: 29 + this.dayYPos(2),
+      },
+      {
         text: 'F',
-        y: 29 + (this.daySizeWithSpace * 5),
+        y: 29 + this.dayYPos(3),
       },
     ];
-    this.svg.append('g')
+    this.svg
+      .append('g')
       .selectAll('text')
-        .data(days)
-        .enter()
-        .append('text')
-          .attr('text-anchor', 'middle')
-          .attr('x', 8)
-          .attr('y', day => day.y)
-          .text(day => day.text)
-          .attr('class', 'user-contrib-text');
+      .data(days)
+      .enter()
+      .append('text')
+      .attr('text-anchor', 'middle')
+      .attr('x', 8)
+      .attr('y', day => day.y)
+      .text(day => day.text)
+      .attr('class', 'user-contrib-text');
   }
 
   renderMonths() {
-    this.svg.append('g')
+    this.svg
+      .append('g')
       .attr('direction', 'ltr')
       .selectAll('text')
-        .data(this.months)
-        .enter()
-        .append('text')
-          .attr('x', date => date.x)
-          .attr('y', 10)
-          .attr('class', 'user-contrib-text')
-          .text(date => this.monthNames[date.month]);
+      .data(this.months)
+      .enter()
+      .append('text')
+      .attr('x', date => date.x)
+      .attr('y', 10)
+      .attr('class', 'user-contrib-text')
+      .text(date => this.monthNames[date.month]);
   }
 
   renderKey() {
-    const keyValues = ['no contributions', '1-9 contributions', '10-19 contributions', '20-29 contributions', '30+ contributions'];
-    const keyColors = ['#ededed', this.colorKey(0), this.colorKey(1), this.colorKey(2), this.colorKey(3)];
+    const keyValues = [
+      'no contributions',
+      '1-9 contributions',
+      '10-19 contributions',
+      '20-29 contributions',
+      '30+ contributions',
+    ];
+    const keyColors = [
+      '#ededed',
+      this.colorKey(0),
+      this.colorKey(1),
+      this.colorKey(2),
+      this.colorKey(3),
+    ];
 
-    this.svg.append('g')
-      .attr('transform', `translate(18, ${(this.daySizeWithSpace * 8) + 16})`)
+    this.svg
+      .append('g')
+      .attr('transform', `translate(18, ${this.daySizeWithSpace * 8 + 16})`)
       .selectAll('rect')
-        .data(keyColors)
-        .enter()
-        .append('rect')
-          .attr('width', this.daySize)
-          .attr('height', this.daySize)
-          .attr('x', (color, i) => this.daySizeWithSpace * i)
-          .attr('y', 0)
-          .attr('fill', color => color)
-          .attr('class', 'js-tooltip')
-          .attr('title', (color, i) => keyValues[i])
-          .attr('data-container', 'body');
+      .data(keyColors)
+      .enter()
+      .append('rect')
+      .attr('width', this.daySize)
+      .attr('height', this.daySize)
+      .attr('x', (color, i) => this.daySizeWithSpace * i)
+      .attr('y', 0)
+      .attr('fill', color => color)
+      .attr('class', 'js-tooltip')
+      .attr('title', (color, i) => keyValues[i])
+      .attr('data-container', 'body');
   }
 
   initColor() {
-    const colorRange = ['#ededed', this.colorKey(0), this.colorKey(1), this.colorKey(2), this.colorKey(3)];
-    return d3.scaleThreshold().domain([0, 10, 20, 30]).range(colorRange);
+    const colorRange = [
+      '#ededed',
+      this.colorKey(0),
+      this.colorKey(1),
+      this.colorKey(2),
+      this.colorKey(3),
+    ];
+    return d3
+      .scaleThreshold()
+      .domain([0, 10, 20, 30])
+      .range(colorRange);
   }
 
   clickDay(stamp) {
@@ -227,14 +281,15 @@ export default class ActivityCalendar {
 
       $('.user-calendar-activities').html(LOADING_HTML);
 
-      axios.get(this.calendarActivitiesPath, {
-        params: {
-          date,
-        },
-        responseType: 'text',
-      })
-      .then(({ data }) => $('.user-calendar-activities').html(data))
-      .catch(() => flash(__('An error occurred while retrieving calendar activity')));
+      axios
+        .get(this.calendarActivitiesPath, {
+          params: {
+            date,
+          },
+          responseType: 'text',
+        })
+        .then(({ data }) => $('.user-calendar-activities').html(data))
+        .catch(() => flash(__('An error occurred while retrieving calendar activity')));
     } else {
       this.currentSelectedDate = '';
       $('.user-calendar-activities').html('');
diff --git a/app/assets/javascripts/right_sidebar.js b/app/assets/javascripts/right_sidebar.js
index 2088a49590a..6eb0b62fa1c 100644
--- a/app/assets/javascripts/right_sidebar.js
+++ b/app/assets/javascripts/right_sidebar.js
@@ -5,6 +5,7 @@ import _ from 'underscore';
 import Cookies from 'js-cookie';
 import flash from './flash';
 import axios from './lib/utils/axios_utils';
+import { __ } from './locale';
 
 function Sidebar(currentUser) {
   this.toggleTodo = this.toggleTodo.bind(this);
@@ -41,12 +42,14 @@ Sidebar.prototype.addEventListeners = function() {
 };
 
 Sidebar.prototype.sidebarToggleClicked = function (e, triggered) {
-  var $allGutterToggleIcons, $this, $thisIcon;
+  var $allGutterToggleIcons, $this, isExpanded, tooltipLabel;
   e.preventDefault();
   $this = $(this);
-  $thisIcon = $this.find('i');
+  isExpanded = $this.find('i').hasClass('fa-angle-double-right');
+  tooltipLabel = isExpanded ? __('Expand sidebar') : __('Collapse sidebar');
   $allGutterToggleIcons = $('.js-sidebar-toggle i');
-  if ($thisIcon.hasClass('fa-angle-double-right')) {
+
+  if (isExpanded) {
     $allGutterToggleIcons.removeClass('fa-angle-double-right').addClass('fa-angle-double-left');
     $('aside.right-sidebar').removeClass('right-sidebar-expanded').addClass('right-sidebar-collapsed');
     $('.layout-page').removeClass('right-sidebar-expanded').addClass('right-sidebar-collapsed');
@@ -57,6 +60,9 @@ Sidebar.prototype.sidebarToggleClicked = function (e, triggered) {
 
     if (gl.lazyLoader) gl.lazyLoader.loadCheck();
   }
+
+  $this.attr('data-original-title', tooltipLabel);
+
   if (!triggered) {
     Cookies.set("collapsed_gutter", $('.right-sidebar').hasClass('right-sidebar-collapsed'));
   }
diff --git a/app/assets/javascripts/sidebar/components/assignees/assignees.vue b/app/assets/javascripts/sidebar/components/assignees/assignees.vue
index 1e7f46454bf..2d00e8ac7e0 100644
--- a/app/assets/javascripts/sidebar/components/assignees/assignees.vue
+++ b/app/assets/javascripts/sidebar/components/assignees/assignees.vue
@@ -1,6 +1,12 @@
 <script>
+import { __ } from '~/locale';
+import tooltip from '~/vue_shared/directives/tooltip';
+
 export default {
   name: 'Assignees',
+  directives: {
+    tooltip,
+  },
   props: {
     rootPath: {
       type: String,
@@ -14,6 +20,11 @@ export default {
       type: Boolean,
       required: true,
     },
+    issuableType: {
+      type: String,
+      require: true,
+      default: 'issue',
+    },
   },
   data() {
     return {
@@ -62,6 +73,12 @@ export default {
         names.push(`+ ${this.users.length - maxRender} more`);
       }
 
+      if (!this.users.length) {
+        const emptyTooltipLabel = this.issuableType === 'issue' ?
+          __('Assignee(s)') : __('Assignee');
+        names.push(emptyTooltipLabel);
+      }
+
       return names.join(', ');
     },
     sidebarAvatarCounter() {
@@ -109,7 +126,8 @@ export default {
   <div>
     <div
       class="sidebar-collapsed-icon sidebar-collapsed-user"
-      :class="{ 'multiple-users': hasMoreThanOneAssignee, 'has-tooltip': hasAssignees }"
+      :class="{ 'multiple-users': hasMoreThanOneAssignee }"
+      v-tooltip
       data-container="body"
       data-placement="left"
       :title="collapsedTooltipTitle"
diff --git a/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue b/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue
index 3c6b9c27814..b04a2eff798 100644
--- a/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue
+++ b/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue
@@ -1,9 +1,9 @@
 <script>
-import Flash from '../../../flash';
+import Flash from '~/flash';
+import eventHub from '~/sidebar/event_hub';
+import Store from '~/sidebar/stores/sidebar_store';
 import AssigneeTitle from './assignee_title.vue';
 import Assignees from './assignees.vue';
-import Store from '../../stores/sidebar_store';
-import eventHub from '../../event_hub';
 
 export default {
   name: 'SidebarAssignees',
@@ -25,6 +25,11 @@ export default {
       required: false,
       default: false,
     },
+    issuableType: {
+      type: String,
+      require: true,
+      default: 'issue',
+    },
   },
   data() {
     return {
@@ -90,6 +95,7 @@ export default {
       :users="store.assignees"
       :editable="store.editable"
       @assign-self="assignSelf"
+      :issuable-type="issuableType"
     />
   </div>
 </template>
diff --git a/app/assets/javascripts/sidebar/components/confidential/confidential_issue_sidebar.vue b/app/assets/javascripts/sidebar/components/confidential/confidential_issue_sidebar.vue
index ceb02309959..7f0de722f61 100644
--- a/app/assets/javascripts/sidebar/components/confidential/confidential_issue_sidebar.vue
+++ b/app/assets/javascripts/sidebar/components/confidential/confidential_issue_sidebar.vue
@@ -1,15 +1,19 @@
 <script>
-import Flash from '../../../flash';
+import { __ } from '~/locale';
+import Flash from '~/flash';
+import tooltip from '~/vue_shared/directives/tooltip';
+import Icon from '~/vue_shared/components/icon.vue';
+import eventHub from '~/sidebar/event_hub';
 import editForm from './edit_form.vue';
-import Icon from '../../../vue_shared/components/icon.vue';
-import { __ } from '../../../locale';
-import eventHub from '../../event_hub';
 
 export default {
   components: {
     editForm,
     Icon,
   },
+  directives: {
+    tooltip,
+  },
   props: {
     isConfidential: {
       required: true,
@@ -33,6 +37,9 @@ export default {
     confidentialityIcon() {
       return this.isConfidential ? 'eye-slash' : 'eye';
     },
+    tooltipLabel() {
+      return this.isConfidential ? __('Confidential') : __('Not confidential');
+    },
   },
   created() {
     eventHub.$on('closeConfidentialityForm', this.toggleForm);
@@ -65,6 +72,10 @@ export default {
     <div
       class="sidebar-collapsed-icon"
       @click="toggleForm"
+      v-tooltip
+      data-container="body"
+      data-placement="left"
+      :title="tooltipLabel"
     >
       <icon
         :name="confidentialityIcon"
diff --git a/app/assets/javascripts/sidebar/components/lock/lock_issue_sidebar.vue b/app/assets/javascripts/sidebar/components/lock/lock_issue_sidebar.vue
index e4893451af3..1a5e7b67eca 100644
--- a/app/assets/javascripts/sidebar/components/lock/lock_issue_sidebar.vue
+++ b/app/assets/javascripts/sidebar/components/lock/lock_issue_sidebar.vue
@@ -1,15 +1,22 @@
 <script>
+import { __ } from '~/locale';
 import Flash from '~/flash';
+import tooltip from '~/vue_shared/directives/tooltip';
+import issuableMixin from '~/vue_shared/mixins/issuable';
+import Icon from '~/vue_shared/components/icon.vue';
+import eventHub from '~/sidebar/event_hub';
 import editForm from './edit_form.vue';
-import issuableMixin from '../../../vue_shared/mixins/issuable';
-import Icon from '../../../vue_shared/components/icon.vue';
-import eventHub from '../../event_hub';
 
 export default {
   components: {
     editForm,
     Icon,
   },
+
+  directives: {
+    tooltip,
+  },
+
   mixins: [issuableMixin],
 
   props: {
@@ -44,6 +51,10 @@ export default {
     isLockDialogOpen() {
       return this.mediator.store.isLockDialogOpen;
     },
+
+    tooltipLabel() {
+      return this.isLocked ? __('Locked') : __('Unlocked');
+    },
   },
 
   created() {
@@ -85,6 +96,10 @@ export default {
     <div
       class="sidebar-collapsed-icon"
       @click="toggleForm"
+      v-tooltip
+      data-container="body"
+      data-placement="left"
+      :title="tooltipLabel"
     >
       <icon
         :name="lockIcon"
diff --git a/app/assets/javascripts/sidebar/components/participants/participants.vue b/app/assets/javascripts/sidebar/components/participants/participants.vue
index 006a6d2905d..6d95153af28 100644
--- a/app/assets/javascripts/sidebar/components/participants/participants.vue
+++ b/app/assets/javascripts/sidebar/components/participants/participants.vue
@@ -1,9 +1,13 @@
 <script>
-  import { __, n__, sprintf } from '../../../locale';
-  import loadingIcon from '../../../vue_shared/components/loading_icon.vue';
-  import userAvatarImage from '../../../vue_shared/components/user_avatar/user_avatar_image.vue';
+  import { __, n__, sprintf } from '~/locale';
+  import tooltip from '~/vue_shared/directives/tooltip';
+  import loadingIcon from '~/vue_shared/components/loading_icon.vue';
+  import userAvatarImage from '~/vue_shared/components/user_avatar/user_avatar_image.vue';
 
   export default {
+    directives: {
+      tooltip,
+    },
     components: {
       loadingIcon,
       userAvatarImage,
@@ -72,7 +76,13 @@
 
 <template>
   <div>
-    <div class="sidebar-collapsed-icon">
+    <div
+      class="sidebar-collapsed-icon"
+      v-tooltip
+      data-container="body"
+      data-placement="left"
+      :title="participantLabel"
+    >
       <i
         class="fa fa-users"
         aria-hidden="true"
diff --git a/app/assets/javascripts/sidebar/components/time_tracking/collapsed_state.vue b/app/assets/javascripts/sidebar/components/time_tracking/collapsed_state.vue
index 3b86f1145d1..9d9ee9dea4d 100644
--- a/app/assets/javascripts/sidebar/components/time_tracking/collapsed_state.vue
+++ b/app/assets/javascripts/sidebar/components/time_tracking/collapsed_state.vue
@@ -1,12 +1,17 @@
 <script>
-  import icon from '../../../vue_shared/components/icon.vue';
-  import { abbreviateTime } from '../../../lib/utils/pretty_time';
+  import { __, sprintf } from '~/locale';
+  import { abbreviateTime } from '~/lib/utils/pretty_time';
+  import icon from '~/vue_shared/components/icon.vue';
+  import tooltip from '~/vue_shared/directives/tooltip';
 
   export default {
     name: 'TimeTrackingCollapsedState',
     components: {
       icon,
     },
+    directives: {
+      tooltip,
+    },
     props: {
       showComparisonState: {
         type: Boolean,
@@ -79,6 +84,21 @@
 
         return '';
       },
+      timeTrackedTooltipText() {
+        let title;
+        if (this.showComparisonState) {
+          title = __('Time remaining');
+        } else if (this.showEstimateOnlyState) {
+          title = __('Estimated');
+        } else if (this.showSpentOnlyState) {
+          title = __('Time spent');
+        }
+
+        return sprintf('%{title}: %{text}', ({ title, text: this.text }));
+      },
+      tooltipText() {
+        return this.showNoTimeTrackingState ? __('Time tracking') : this.timeTrackedTooltipText;
+      },
     },
     methods: {
       abbreviateTime(timeStr) {
@@ -89,7 +109,13 @@
 </script>
 
 <template>
-  <div class="sidebar-collapsed-icon">
+  <div
+    class="sidebar-collapsed-icon"
+    v-tooltip
+    data-container="body"
+    data-placement="left"
+    :title="tooltipText"
+  >
     <icon name="timer" />
     <div class="time-tracking-collapsed-summary">
       <div :class="divClass">
diff --git a/app/assets/javascripts/sidebar/mount_sidebar.js b/app/assets/javascripts/sidebar/mount_sidebar.js
index 9f5d852260e..26eb4cffba3 100644
--- a/app/assets/javascripts/sidebar/mount_sidebar.js
+++ b/app/assets/javascripts/sidebar/mount_sidebar.js
@@ -27,6 +27,7 @@ function mountAssigneesComponent(mediator) {
         mediator,
         field: el.dataset.field,
         signedIn: el.hasAttribute('data-signed-in'),
+        issuableType: gl.utils.isInIssuePage() ? 'issue' : 'merge_request',
       },
     }),
   });
diff --git a/app/assets/javascripts/users_select.js b/app/assets/javascripts/users_select.js
index 520a0b3f424..8486019897d 100644
--- a/app/assets/javascripts/users_select.js
+++ b/app/assets/javascripts/users_select.js
@@ -5,6 +5,7 @@
 import $ from 'jquery';
 import _ from 'underscore';
 import axios from './lib/utils/axios_utils';
+import { __ } from './locale';
 import ModalStore from './boards/stores/modal_store';
 
 // TODO: remove eventHub hack after code splitting refactor
@@ -182,7 +183,7 @@ function UsersSelect(currentUser, els, options = {}) {
 
         return axios.put(issueURL, data)
           .then(({ data }) => {
-            var user;
+            var user, tooltipTitle;
             $dropdown.trigger('loaded.gl.dropdown');
             $loading.fadeOut();
             if (data.assignee) {
@@ -191,15 +192,17 @@ function UsersSelect(currentUser, els, options = {}) {
                 username: data.assignee.username,
                 avatar: data.assignee.avatar_url
               };
+              tooltipTitle = _.escape(user.name);
             } else {
               user = {
                 name: 'Unassigned',
                 username: '',
                 avatar: ''
               };
+              tooltipTitle = __('Assignee');
             }
             $value.html(assigneeTemplate(user));
-            $collapsedSidebar.attr('title', _.escape(user.name)).tooltip('fixTitle');
+            $collapsedSidebar.attr('title', tooltipTitle).tooltip('fixTitle');
             return $collapsedSidebar.html(collapsedAssigneeTemplate(user));
           });
       };
diff --git a/app/assets/javascripts/vue_shared/components/sidebar/toggle_sidebar.vue b/app/assets/javascripts/vue_shared/components/sidebar/toggle_sidebar.vue
index 8211d425b1f..de6f8c32e74 100644
--- a/app/assets/javascripts/vue_shared/components/sidebar/toggle_sidebar.vue
+++ b/app/assets/javascripts/vue_shared/components/sidebar/toggle_sidebar.vue
@@ -1,18 +1,29 @@
 <script>
-  export default {
-    name: 'ToggleSidebar',
-    props: {
-      collapsed: {
-        type: Boolean,
-        required: true,
-      },
+import { __ } from '~/locale';
+import tooltip from '~/vue_shared/directives/tooltip';
+
+export default {
+  name: 'ToggleSidebar',
+  directives: {
+    tooltip,
+  },
+  props: {
+    collapsed: {
+      type: Boolean,
+      required: true,
+    },
+  },
+  computed: {
+    tooltipLabel() {
+      return this.collapsed ? __('Expand sidebar') : __('Collapse sidebar');
     },
-    methods: {
-      toggle() {
-        this.$emit('toggle');
-      },
+  },
+  methods: {
+    toggle() {
+      this.$emit('toggle');
     },
-  };
+  },
+};
 </script>
 
 <template>
@@ -20,6 +31,10 @@
     type="button"
     class="btn btn-blank gutter-toggle btn-sidebar-action"
     @click="toggle"
+    v-tooltip
+    data-container="body"
+    data-placement="left"
+    :title="tooltipLabel"
   >
     <i
       aria-label="toggle collapse"