Merge branch '21143-customize-branch-name-when-using-create-branch-in-an-issue' into 'master'

Resolve "Customize branch name when using create branch in an issue"

Closes #21143

See merge request gitlab-org/gitlab-ce!13884

15 files changed, 831 insertions, 271 deletions

diff --git a/app/assets/javascripts/create_merge_request_dropdown.js b/app/assets/javascripts/create_merge_request_dropdown.js
index bf40eb3ee11..23425672b16 100644
--- a/app/assets/javascripts/create_merge_request_dropdown.js
+++ b/app/assets/javascripts/create_merge_request_dropdown.js
@@ -2,6 +2,7 @@
 import Flash from './flash';
 import DropLab from './droplab/drop_lab';
 import ISetter from './droplab/plugins/input_setter';
+import { __, sprintf } from './locale';
 
 // Todo: Remove this when fixing issue in input_setter plugin
 const InputSetter = Object.assign({}, ISetter);
@@ -12,28 +13,49 @@ const CREATE_BRANCH = 'create-branch';
 export default class CreateMergeRequestDropdown {
   constructor(wrapperEl) {
     this.wrapperEl = wrapperEl;
+    this.availableButton = this.wrapperEl.querySelector('.available');
+    this.branchInput = this.wrapperEl.querySelector('.js-branch-name');
+    this.branchMessage = this.wrapperEl.querySelector('.js-branch-message');
     this.createMergeRequestButton = this.wrapperEl.querySelector('.js-create-merge-request');
-    this.dropdownToggle = this.wrapperEl.querySelector('.js-dropdown-toggle');
+    this.createTargetButton = this.wrapperEl.querySelector('.js-create-target');
     this.dropdownList = this.wrapperEl.querySelector('.dropdown-menu');
-    this.availableButton = this.wrapperEl.querySelector('.available');
+    this.dropdownToggle = this.wrapperEl.querySelector('.js-dropdown-toggle');
+    this.refInput = this.wrapperEl.querySelector('.js-ref');
+    this.refMessage = this.wrapperEl.querySelector('.js-ref-message');
     this.unavailableButton = this.wrapperEl.querySelector('.unavailable');
     this.unavailableButtonArrow = this.unavailableButton.querySelector('.fa');
     this.unavailableButtonText = this.unavailableButton.querySelector('.text');
 
-    this.createBranchPath = this.wrapperEl.dataset.createBranchPath;
+    this.branchCreated = false;
+    this.branchIsValid = true;
     this.canCreatePath = this.wrapperEl.dataset.canCreatePath;
+    this.createBranchPath = this.wrapperEl.dataset.createBranchPath;
     this.createMrPath = this.wrapperEl.dataset.createMrPath;
     this.droplabInitialized = false;
+    this.isCreatingBranch = false;
     this.isCreatingMergeRequest = false;
+    this.isGettingRef = false;
     this.mergeRequestCreated = false;
-    this.isCreatingBranch = false;
-    this.branchCreated = false;
+    this.refDebounce = _.debounce((value, target) => this.getRef(value, target), 500);
+    this.refIsValid = true;
+    this.refsPath = this.wrapperEl.dataset.refsPath;
+    this.suggestedRef = this.refInput.value;
 
-    this.init();
-  }
+    // These regexps are used to replace
+    // a backend generated new branch name and its source (ref)
+    // with user's inputs.
+    this.regexps = {
+      branch: {
+        createBranchPath: new RegExp('(branch_name=)(.+?)(?=&issue)'),
+        createMrPath: new RegExp('(branch_name=)(.+?)(?=&ref)'),
+      },
+      ref: {
+        createBranchPath: new RegExp('(ref=)(.+?)$'),
+        createMrPath: new RegExp('(ref=)(.+?)$'),
+      },
+    };
 
-  init() {
-    this.checkAbilityToCreateBranch();
+    this.init();
   }
 
   available() {
@@ -41,41 +63,13 @@ export default class CreateMergeRequestDropdown {
     this.unavailableButton.classList.add('hide');
   }
 
-  unavailable() {
-    this.availableButton.classList.add('hide');
-    this.unavailableButton.classList.remove('hide');
-  }
-
-  enable() {
-    this.createMergeRequestButton.classList.remove('disabled');
-    this.createMergeRequestButton.removeAttribute('disabled');
-
-    this.dropdownToggle.classList.remove('disabled');
-    this.dropdownToggle.removeAttribute('disabled');
-  }
-
-  disable() {
-    this.createMergeRequestButton.classList.add('disabled');
-    this.createMergeRequestButton.setAttribute('disabled', 'disabled');
-
-    this.dropdownToggle.classList.add('disabled');
-    this.dropdownToggle.setAttribute('disabled', 'disabled');
-  }
-
-  hide() {
-    this.wrapperEl.classList.add('hide');
-  }
-
-  setUnavailableButtonState(isLoading = true) {
-    if (isLoading) {
-      this.unavailableButtonArrow.classList.add('fa-spinner', 'fa-spin');
-      this.unavailableButtonArrow.classList.remove('fa-exclamation-triangle');
-      this.unavailableButtonText.textContent = 'Checking branch availability…';
-    } else {
-      this.unavailableButtonArrow.classList.remove('fa-spinner', 'fa-spin');
-      this.unavailableButtonArrow.classList.add('fa-exclamation-triangle');
-      this.unavailableButtonText.textContent = 'New branch unavailable';
-    }
+  bindEvents() {
+    this.createMergeRequestButton.addEventListener('click', this.onClickCreateMergeRequestButton.bind(this));
+    this.createTargetButton.addEventListener('click', this.onClickCreateMergeRequestButton.bind(this));
+    this.branchInput.addEventListener('keyup', this.onChangeInput.bind(this));
+    this.dropdownToggle.addEventListener('click', this.onClickSetFocusOnBranchNameInput.bind(this));
+    this.refInput.addEventListener('keyup', this.onChangeInput.bind(this));
+    this.refInput.addEventListener('keydown', CreateMergeRequestDropdown.processTab.bind(this));
   }
 
   checkAbilityToCreateBranch() {
@@ -107,49 +101,233 @@ export default class CreateMergeRequestDropdown {
     });
   }
 
-  initDroplab() {
-    this.droplab = new DropLab();
+  createBranch() {
+    return $.ajax({
+      method: 'POST',
+      dataType: 'json',
+      url: this.createBranchPath,
+      beforeSend: () => (this.isCreatingBranch = true),
+    })
+    .done((data) => {
+      this.branchCreated = true;
+      window.location.href = data.url;
+    })
+    .fail(() => new Flash('Failed to create a branch for this issue. Please try again.'));
+  }
 
-    this.droplab.init(this.dropdownToggle, this.dropdownList, [InputSetter],
-      this.getDroplabConfig());
+  createMergeRequest() {
+    return $.ajax({
+      method: 'POST',
+      dataType: 'json',
+      url: this.createMrPath,
+      beforeSend: () => (this.isCreatingMergeRequest = true),
+    })
+    .done((data) => {
+      this.mergeRequestCreated = true;
+      window.location.href = data.url;
+    })
+    .fail(() => new Flash('Failed to create Merge Request. Please try again.'));
+  }
+
+  disable() {
+    this.disableCreateAction();
+
+    this.dropdownToggle.classList.add('disabled');
+    this.dropdownToggle.setAttribute('disabled', 'disabled');
+  }
+
+  disableCreateAction() {
+    this.createMergeRequestButton.classList.add('disabled');
+    this.createMergeRequestButton.setAttribute('disabled', 'disabled');
+
+    this.createTargetButton.classList.add('disabled');
+    this.createTargetButton.setAttribute('disabled', 'disabled');
+  }
+
+  enable() {
+    this.createMergeRequestButton.classList.remove('disabled');
+    this.createMergeRequestButton.removeAttribute('disabled');
+
+    this.createTargetButton.classList.remove('disabled');
+    this.createTargetButton.removeAttribute('disabled');
+
+    this.dropdownToggle.classList.remove('disabled');
+    this.dropdownToggle.removeAttribute('disabled');
+  }
+
+  static findByValue(objects, ref, returnFirstMatch = false) {
+    if (!objects || !objects.length) return false;
+    if (objects.indexOf(ref) > -1) return ref;
+    if (returnFirstMatch) return objects.find(item => new RegExp(`^${ref}`).test(item));
+
+    return false;
   }
 
   getDroplabConfig() {
     return {
-      InputSetter: [{
-        input: this.createMergeRequestButton,
-        valueAttribute: 'data-value',
-        inputAttribute: 'data-action',
-      }, {
-        input: this.createMergeRequestButton,
-        valueAttribute: 'data-text',
-      }],
+      addActiveClassToDropdownButton: true,
+      InputSetter: [
+        {
+          input: this.createMergeRequestButton,
+          valueAttribute: 'data-value',
+          inputAttribute: 'data-action',
+        },
+        {
+          input: this.createMergeRequestButton,
+          valueAttribute: 'data-text',
+        },
+        {
+          input: this.createTargetButton,
+          valueAttribute: 'data-value',
+          inputAttribute: 'data-action',
+        },
+        {
+          input: this.createTargetButton,
+          valueAttribute: 'data-text',
+        },
+      ],
     };
   }
 
-  bindEvents() {
-    this.createMergeRequestButton
-      .addEventListener('click', this.onClickCreateMergeRequestButton.bind(this));
+  static getInputSelectedText(input) {
+    const start = input.selectionStart;
+    const end = input.selectionEnd;
+
+    return input.value.substr(start, end - start);
+  }
+
+  getRef(ref, target = 'all') {
+    if (!ref) return false;
+
+    return $.ajax({
+      method: 'GET',
+      dataType: 'json',
+      url: this.refsPath + ref,
+      beforeSend: () => {
+        this.isGettingRef = true;
+      },
+    })
+    .always(() => {
+      this.isGettingRef = false;
+    })
+    .done((data) => {
+      const branches = data[Object.keys(data)[0]];
+      const tags = data[Object.keys(data)[1]];
+      let result;
+
+      if (target === 'branch') {
+        result = CreateMergeRequestDropdown.findByValue(branches, ref);
+      } else {
+        result = CreateMergeRequestDropdown.findByValue(branches, ref, true) ||
+          CreateMergeRequestDropdown.findByValue(tags, ref, true);
+        this.suggestedRef = result;
+      }
+
+      return this.updateInputState(target, ref, result);
+    })
+    .fail(() => {
+      this.unavailable();
+      this.disable();
+      new Flash('Failed to get ref.');
+
+      return false;
+    });
+  }
+
+  getTargetData(target) {
+    return {
+      input: this[`${target}Input`],
+      message: this[`${target}Message`],
+    };
+  }
+
+  hide() {
+    this.wrapperEl.classList.add('hide');
+  }
+
+  init() {
+    this.checkAbilityToCreateBranch();
+  }
+
+  initDroplab() {
+    this.droplab = new DropLab();
+
+    this.droplab.init(
+      this.dropdownToggle,
+      this.dropdownList,
+      [InputSetter],
+      this.getDroplabConfig(),
+    );
+  }
+
+  inputsAreValid() {
+    return this.branchIsValid && this.refIsValid;
   }
 
   isBusy() {
     return this.isCreatingMergeRequest ||
       this.mergeRequestCreated ||
       this.isCreatingBranch ||
-      this.branchCreated;
+      this.branchCreated ||
+      this.isGettingRef;
   }
 
-  onClickCreateMergeRequestButton(e) {
+  onChangeInput(event) {
+    let target;
+    let value;
+
+    if (event.srcElement === this.branchInput) {
+      target = 'branch';
+      value = this.branchInput.value;
+    } else if (event.srcElement === this.refInput) {
+      target = 'ref';
+      value = event.srcElement.value.slice(0, event.srcElement.selectionStart) +
+        event.srcElement.value.slice(event.srcElement.selectionEnd);
+    } else {
+      return false;
+    }
+
+    if (this.isGettingRef) return false;
+
+    // `ENTER` key submits the data.
+    if (event.keyCode === 13 && this.inputsAreValid()) {
+      event.preventDefault();
+      return this.createMergeRequestButton.click();
+    }
+
+    // If the input is empty, use the original value generated by the backend.
+    if (!value) {
+      this.createBranchPath = this.wrapperEl.dataset.createBranchPath;
+      this.createMrPath = this.wrapperEl.dataset.createMrPath;
+
+      if (target === 'branch') {
+        this.branchIsValid = true;
+      } else {
+        this.refIsValid = true;
+      }
+
+      this.enable();
+      this.showAvailableMessage(target);
+      return true;
+    }
+
+    this.showCheckingMessage(target);
+    this.refDebounce(value, target);
+
+    return true;
+  }
+
+  onClickCreateMergeRequestButton(event) {
     let xhr = null;
-    e.preventDefault();
+    event.preventDefault();
 
     if (this.isBusy()) {
       return;
     }
 
-    if (e.target.dataset.action === CREATE_MERGE_REQUEST) {
+    if (event.target.dataset.action === CREATE_MERGE_REQUEST) {
       xhr = this.createMergeRequest();
-    } else if (e.target.dataset.action === CREATE_BRANCH) {
+    } else if (event.target.dataset.action === CREATE_BRANCH) {
       xhr = this.createBranch();
     }
 
@@ -163,31 +341,131 @@ export default class CreateMergeRequestDropdown {
     this.disable();
   }
 
-  createMergeRequest() {
-    return $.ajax({
-      method: 'POST',
-      dataType: 'json',
-      url: this.createMrPath,
-      beforeSend: () => (this.isCreatingMergeRequest = true),
-    })
-    .done((data) => {
-      this.mergeRequestCreated = true;
-      window.location.href = data.url;
-    })
-    .fail(() => new Flash('Failed to create Merge Request. Please try again.'));
+  onClickSetFocusOnBranchNameInput() {
+    this.branchInput.focus();
   }
 
-  createBranch() {
-    return $.ajax({
-      method: 'POST',
-      dataType: 'json',
-      url: this.createBranchPath,
-      beforeSend: () => (this.isCreatingBranch = true),
-    })
-    .done((data) => {
-      this.branchCreated = true;
-      window.location.href = data.url;
-    })
-    .fail(() => new Flash('Failed to create a branch for this issue. Please try again.'));
+  // `TAB` autocompletes the source.
+  static processTab(event) {
+    if (event.keyCode !== 9 || this.isGettingRef) return;
+
+    const selectedText = CreateMergeRequestDropdown.getInputSelectedText(this.refInput);
+
+    // if nothing selected, we don't need to autocomplete anything. Do the default TAB action.
+    // If a user manually selected text, don't autocomplete anything. Do the default TAB action.
+    if (!selectedText || this.refInput.dataset.value === this.suggestedRef) return;
+
+    event.preventDefault();
+    window.getSelection().removeAllRanges();
+  }
+
+  removeMessage(target) {
+    const { input, message } = this.getTargetData(target);
+    const inputClasses = ['gl-field-error-outline', 'gl-field-success-outline'];
+    const messageClasses = ['gl-field-hint', 'gl-field-error-message', 'gl-field-success-message'];
+
+    inputClasses.forEach(cssClass => input.classList.remove(cssClass));
+    messageClasses.forEach(cssClass => message.classList.remove(cssClass));
+    message.style.display = 'none';
+  }
+
+  setUnavailableButtonState(isLoading = true) {
+    if (isLoading) {
+      this.unavailableButtonArrow.classList.add('fa-spin');
+      this.unavailableButtonArrow.classList.add('fa-spinner');
+      this.unavailableButtonArrow.classList.remove('fa-exclamation-triangle');
+      this.unavailableButtonText.textContent = __('Checking branch availability...');
+    } else {
+      this.unavailableButtonArrow.classList.remove('fa-spin');
+      this.unavailableButtonArrow.classList.remove('fa-spinner');
+      this.unavailableButtonArrow.classList.add('fa-exclamation-triangle');
+      this.unavailableButtonText.textContent = __('New branch unavailable');
+    }
+  }
+
+  showAvailableMessage(target) {
+    const { input, message } = this.getTargetData(target);
+    const text = target === 'branch' ? __('Branch name') : __('Source');
+
+    this.removeMessage(target);
+    input.classList.add('gl-field-success-outline');
+    message.classList.add('gl-field-success-message');
+    message.textContent = sprintf(__('%{text} is available'), { text });
+    message.style.display = 'inline-block';
+  }
+
+  showCheckingMessage(target) {
+    const { message } = this.getTargetData(target);
+    const text = target === 'branch' ? __('branch name') : __('source');
+
+    this.removeMessage(target);
+    message.classList.add('gl-field-hint');
+    message.textContent = sprintf(__('Checking %{text} availability…'), { text });
+    message.style.display = 'inline-block';
+  }
+
+  showNotAvailableMessage(target) {
+    const { input, message } = this.getTargetData(target);
+    const text = target === 'branch' ? __('Branch is already taken') : __('Source is not available');
+
+    this.removeMessage(target);
+    input.classList.add('gl-field-error-outline');
+    message.classList.add('gl-field-error-message');
+    message.textContent = text;
+    message.style.display = 'inline-block';
+  }
+
+  unavailable() {
+    this.availableButton.classList.add('hide');
+    this.unavailableButton.classList.remove('hide');
+  }
+
+  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) {
+      if (target === 'branch') {
+        this.branchIsValid = false;
+        this.showNotAvailableMessage('branch');
+      } else {
+        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);
+      }
+    } 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);
+    } else {
+      this.refIsValid = false;
+      this.refInput.dataset.value = ref;
+      this.disableCreateAction();
+      this.showNotAvailableMessage('ref');
+
+      // Show ref hint.
+      if (result) {
+        this.refInput.value = result;
+        this.refInput.setSelectionRange(ref.length, result.length);
+      }
+    }
+
+    if (this.inputsAreValid()) {
+      this.enable();
+    } else {
+      this.disableCreateAction();
+    }
   }
 }
diff --git a/app/assets/javascripts/droplab/constants.js b/app/assets/javascripts/droplab/constants.js
index 868d47e91b3..673e9bb4c0f 100644
--- a/app/assets/javascripts/droplab/constants.js
+++ b/app/assets/javascripts/droplab/constants.js
@@ -3,6 +3,7 @@ const DATA_DROPDOWN = 'data-dropdown';
 const SELECTED_CLASS = 'droplab-item-selected';
 const ACTIVE_CLASS = 'droplab-item-active';
 const IGNORE_CLASS = 'droplab-item-ignore';
+const IGNORE_HIDING_CLASS = 'droplab-item-ignore-hiding';
 // Matches `{{anything}}` and `{{ everything }}`.
 const TEMPLATE_REGEX = /\{\{(.+?)\}\}/g;
 
@@ -13,4 +14,5 @@ export {
   ACTIVE_CLASS,
   TEMPLATE_REGEX,
   IGNORE_CLASS,
+  IGNORE_HIDING_CLASS,
 };
diff --git a/app/assets/javascripts/droplab/drop_down.js b/app/assets/javascripts/droplab/drop_down.js
index 3901bb177fe..5eb0a339a1c 100644
--- a/app/assets/javascripts/droplab/drop_down.js
+++ b/app/assets/javascripts/droplab/drop_down.js
@@ -1,15 +1,18 @@
 import utils from './utils';
-import { SELECTED_CLASS, IGNORE_CLASS } from './constants';
+import { SELECTED_CLASS, IGNORE_CLASS, IGNORE_HIDING_CLASS } from './constants';
 
 class DropDown {
-  constructor(list) {
+  constructor(list, config = {}) {
     this.currentIndex = 0;
     this.hidden = true;
     this.list = typeof list === 'string' ? document.querySelector(list) : list;
     this.items = [];
-
     this.eventWrapper = {};
 
+    if (config.addActiveClassToDropdownButton) {
+      this.dropdownToggle = this.list.parentNode.querySelector('.js-dropdown-toggle');
+    }
+
     this.getItems();
     this.initTemplateString();
     this.addEvents();
@@ -42,7 +45,7 @@ class DropDown {
     this.addSelectedClass(selected);
 
     e.preventDefault();
-    this.hide();
+    if (!e.target.classList.contains(IGNORE_HIDING_CLASS)) this.hide();
 
     const listEvent = new CustomEvent('click.dl', {
       detail: {
@@ -67,7 +70,20 @@ class DropDown {
 
   addEvents() {
     this.eventWrapper.clickEvent = this.clickEvent.bind(this);
+    this.eventWrapper.closeDropdown = this.closeDropdown.bind(this);
+
     this.list.addEventListener('click', this.eventWrapper.clickEvent);
+    this.list.addEventListener('keyup', this.eventWrapper.closeDropdown);
+  }
+
+  closeDropdown(event) {
+    // `ESC` key closes the dropdown.
+    if (event.keyCode === 27) {
+      event.preventDefault();
+      return this.toggle();
+    }
+
+    return true;
   }
 
   setData(data) {
@@ -110,6 +126,8 @@ class DropDown {
     this.list.style.display = 'block';
     this.currentIndex = 0;
     this.hidden = false;
+
+    if (this.dropdownToggle) this.dropdownToggle.classList.add('active');
   }
 
   hide() {
@@ -117,6 +135,8 @@ class DropDown {
     this.list.style.display = 'none';
     this.currentIndex = 0;
     this.hidden = true;
+
+    if (this.dropdownToggle) this.dropdownToggle.classList.remove('active');
   }
 
   toggle() {
@@ -128,6 +148,7 @@ class DropDown {
   destroy() {
     this.hide();
     this.list.removeEventListener('click', this.eventWrapper.clickEvent);
+    this.list.removeEventListener('keyup', this.eventWrapper.closeDropdown);
   }
 
   static setImagesSrc(template) {
diff --git a/app/assets/javascripts/droplab/hook.js b/app/assets/javascripts/droplab/hook.js
index cf78165b0d8..8a8dcde9f88 100644
--- a/app/assets/javascripts/droplab/hook.js
+++ b/app/assets/javascripts/droplab/hook.js
@@ -3,7 +3,7 @@ import DropDown from './drop_down';
 class Hook {
   constructor(trigger, list, plugins, config) {
     this.trigger = trigger;
-    this.list = new DropDown(list);
+    this.list = new DropDown(list, config);
     this.type = 'Hook';
     this.event = 'click';
     this.plugins = plugins || [];
diff --git a/app/assets/stylesheets/pages/issues.scss b/app/assets/stylesheets/pages/issues.scss
index 8bb68ad2425..d3dda2e7d25 100644
--- a/app/assets/stylesheets/pages/issues.scss
+++ b/app/assets/stylesheets/pages/issues.scss
@@ -203,7 +203,24 @@ ul.related-merge-requests > li {
 }
 
 .create-mr-dropdown-wrap {
-  @include new-style-dropdown;
+  .branch-message,
+  .ref-message {
+    display: none;
+  }
+
+  .ref::selection {
+    color: $placeholder-text-color;
+  }
+
+  .dropdown {
+    .dropdown-menu-toggle {
+      min-width: 285px;
+    }
+
+    .dropdown-select {
+      width: 285px;
+    }
+  }
 
   .btn-group:not(.hide) {
     display: flex;
@@ -214,15 +231,16 @@ ul.related-merge-requests > li {
     flex-shrink: 0;
   }
 
-  .dropdown-menu {
+  .create-merge-request-dropdown-menu {
     width: 300px;
     opacity: 1;
     visibility: visible;
     transform: translateY(0);
     display: none;
+    margin-top: 4px;
   }
 
-  .dropdown-toggle {
+  .create-merge-request-dropdown-toggle {
     .fa-caret-down {
       pointer-events: none;
       color: inherit;
@@ -230,18 +248,50 @@ ul.related-merge-requests > li {
     }
   }
 
+  .droplab-item-ignore {
+    pointer-events: auto;
+  }
+
+  .create-item {
+    cursor: pointer;
+    margin: 0 1px;
+
+    &:hover,
+    &:focus {
+      background-color: $dropdown-item-hover-bg;
+      color: $gl-text-color;
+    }
+  }
+
+  li.divider {
+    margin: 8px 10px;
+  }
+
   li:not(.divider) {
+    padding: 8px 9px;
+
+    &:last-child {
+      padding-bottom: 8px;
+    }
+
     &.droplab-item-selected {
       .icon-container {
         i {
           visibility: visible;
         }
       }
+
+      .description {
+        display: block;
+      }
+    }
+
+    &.droplab-item-ignore {
+      padding-top: 8px;
     }
 
     .icon-container {
       float: left;
-      padding-left: 6px;
 
       i {
         visibility: hidden;
@@ -249,13 +299,12 @@ ul.related-merge-requests > li {
     }
 
     .description {
-      padding-left: 30px;
-      font-size: 13px;
+      padding-left: 22px;
+    }
 
-      strong {
-        display: block;
-        font-weight: $gl-font-weight-bold;
-      }
+    input,
+    span {
+      margin: 4px 0 0;
     }
   }
 }
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 28fee0465d5..d7a3441a245 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -158,7 +158,8 @@ class Projects::IssuesController < Projects::ApplicationController
   end
 
   def create_merge_request
-    result = ::MergeRequests::CreateFromIssueService.new(project, current_user, issue_iid: issue.iid).execute
+    create_params = params.slice(:branch_name, :ref).merge(issue_iid: issue.iid)
+    result = ::MergeRequests::CreateFromIssueService.new(project, current_user, create_params).execute
 
     if result[:status] == :success
       render json: MergeRequestCreateSerializer.new.represent(result[:merge_request])
diff --git a/app/services/merge_requests/build_service.rb b/app/services/merge_requests/build_service.rb
index 8223e5fed7f..c2fb01466df 100644
--- a/app/services/merge_requests/build_service.rb
+++ b/app/services/merge_requests/build_service.rb
@@ -1,6 +1,8 @@
 module MergeRequests
   class BuildService < MergeRequests::BaseService
     def execute
+      @issue_iid = params.delete(:issue_iid)
+
       self.merge_request = MergeRequest.new(params)
       merge_request.compare_commits = []
       merge_request.source_project  = find_source_project
@@ -116,37 +118,53 @@ module MergeRequests
     #   more than one commit in the MR
     #
     def assign_title_and_description
-      if match = source_branch.match(/\A(\d+)-/)
-        iid = match[1]
-      end
+      assign_title_and_description_from_single_commit
+      assign_title_from_issue
 
-      commits = compare_commits
-      if commits && commits.count == 1
-        commit = commits.first
-        merge_request.title = commit.title
-        merge_request.description ||= commit.description.try(:strip)
-      elsif iid && issue = target_project.get_issue(iid, current_user)
-        case issue
-        when Issue
-          merge_request.title = "Resolve \"#{issue.title}\""
-        when ExternalIssue
-          merge_request.title = "Resolve #{issue.title}"
-        end
+      merge_request.title ||= source_branch.titleize.humanize
+      merge_request.title = wip_title if compare_commits.empty?
+
+      append_closes_description
+    end
+
+    def append_closes_description
+      return unless issue_iid
+
+      closes_issue = "Closes ##{issue_iid}"
+
+      if description.present?
+        merge_request.description += closes_issue.prepend("\n\n")
       else
-        merge_request.title = source_branch.titleize.humanize
+        merge_request.description = closes_issue
       end
+    end
 
-      if iid
-        closes_issue = "Closes ##{iid}"
+    def assign_title_and_description_from_single_commit
+      commits = compare_commits
+
+      return unless commits&.count == 1
+
+      commit = commits.first
+      merge_request.title ||= commit.title
+      merge_request.description ||= commit.description.try(:strip)
+    end
+
+    def assign_title_from_issue
+      return unless issue
 
-        if description.present?
-          merge_request.description += closes_issue.prepend("\n\n")
-        else
-          merge_request.description = closes_issue
+      merge_request.title =
+        case issue
+        when Issue         then "Resolve \"#{issue.title}\""
+        when ExternalIssue then "Resolve #{issue.title}"
         end
-      end
+    end
+
+    def issue_iid
+      @issue_iid ||= source_branch.match(/\A(\d+)-/).try(:[], 1)
+    end
 
-      merge_request.title = wip_title if commits.empty?
+    def issue
+      @issue ||= target_project.get_issue(issue_iid, current_user)
     end
   end
 end
diff --git a/app/services/merge_requests/create_from_issue_service.rb b/app/services/merge_requests/create_from_issue_service.rb
index da39a380451..89dab1dd028 100644
--- a/app/services/merge_requests/create_from_issue_service.rb
+++ b/app/services/merge_requests/create_from_issue_service.rb
@@ -1,7 +1,18 @@
 module MergeRequests
   class CreateFromIssueService < MergeRequests::CreateService
+    def initialize(project, user, params)
+      # branch - the name of new branch
+      # ref    - the source of new branch.
+
+      @branch_name = params[:branch_name]
+      @issue_iid   = params[:issue_iid]
+      @ref         = params[:ref]
+
+      super(project, user)
+    end
+
     def execute
-      return error('Invalid issue iid') unless issue_iid.present? && issue.present?
+      return error('Invalid issue iid') unless @issue_iid.present? && issue.present?
 
       params[:label_ids] = issue.label_ids if issue.label_ids.any?
 
@@ -21,20 +32,16 @@ module MergeRequests
 
     private
 
-    def issue_iid
-      @isssue_iid ||= params.delete(:issue_iid)
-    end
-
     def issue
-      @issue ||= IssuesFinder.new(current_user, project_id: project.id).find_by(iid: issue_iid)
+      @issue ||= IssuesFinder.new(current_user, project_id: project.id).find_by(iid: @issue_iid)
     end
 
     def branch_name
-      @branch_name ||= issue.to_branch_name
+      @branch ||= @branch_name || issue.to_branch_name
     end
 
     def ref
-      project.default_branch || 'master'
+      @ref || project.default_branch || 'master'
     end
 
     def merge_request
@@ -43,6 +50,7 @@ module MergeRequests
 
     def merge_request_params
       {
+        issue_iid: @issue_iid,
         source_project_id: project.id,
         source_branch: branch_name,
         target_project_id: project.id,
diff --git a/app/views/projects/issues/_new_branch.html.haml b/app/views/projects/issues/_new_branch.html.haml
index 4f78102be0c..331d62cf247 100644
--- a/app/views/projects/issues/_new_branch.html.haml
+++ b/app/views/projects/issues/_new_branch.html.haml
@@ -1,34 +1,50 @@
 - can_create_merge_request = can?(current_user, :create_merge_request, @project)
 - data_action = can_create_merge_request ? 'create-mr' : 'create-branch'
-- value = can_create_merge_request ? 'Create a merge request' : 'Create a branch'
+- value = can_create_merge_request ? 'Create merge request' : 'Create branch'
 
 - if can?(current_user, :push_code, @project)
-  .create-mr-dropdown-wrap{ data: { can_create_path: can_create_branch_project_issue_path(@project, @issue), create_mr_path: create_merge_request_project_issue_path(@project, @issue), create_branch_path: project_branches_path(@project, branch_name: @issue.to_branch_name, issue_iid: @issue.iid) } }
+  - can_create_path = can_create_branch_project_issue_path(@project, @issue)
+  - create_mr_path = create_merge_request_project_issue_path(@project, @issue, branch_name: @issue.to_branch_name, ref: @project.default_branch)
+  - create_branch_path = project_branches_path(@project, branch_name: @issue.to_branch_name, ref: @project.default_branch, issue_iid: @issue.iid)
+  - refs_path = refs_namespace_project_path(@project.namespace, @project, search: '')
+
+  .create-mr-dropdown-wrap{ data: { can_create_path: can_create_path, create_mr_path: create_mr_path, create_branch_path: create_branch_path, refs_path: refs_path } }
     .btn-group.unavailable
       %button.btn.btn-grouped{ type: 'button', disabled: 'disabled' }
         = icon('spinner', class: 'fa-spin')
         %span.text
           Checking branch availability…
     .btn-group.available.hide
-      %input.btn.js-create-merge-request.btn-inverted.btn-success{ type: 'button', value: value, data: { action: data_action } }
-      %button.btn.btn-inverted.dropdown-toggle.btn-inverted.btn-success.js-dropdown-toggle{ type: 'button', data: { 'dropdown-trigger' => '#create-merge-request-dropdown' } }
+      %button.btn.js-create-merge-request.btn-default{ type: 'button', data: { action: data_action } }
+        = value
+
+      %button.btn.create-merge-request-dropdown-toggle.dropdown-toggle.btn-default.js-dropdown-toggle{ type: 'button', data: { dropdown: { trigger: '#create-merge-request-dropdown' } } }
         = icon('caret-down')
-      %ul#create-merge-request-dropdown.dropdown-menu.dropdown-menu-align-right{ data: { dropdown: true } }
+
+      %ul#create-merge-request-dropdown.create-merge-request-dropdown-menu.dropdown-menu.dropdown-menu-align-right.gl-show-field-errors{ data: { dropdown: true } }
         - if can_create_merge_request
-          %li.droplab-item-selected{ role: 'button', data: { value: 'create-mr', 'text' => 'Create a merge request' } }
-            .menu-item
-              .icon-container
-                = icon('check')
-              .description
-                %strong Create a merge request
-                %span
-                  Creates a merge request named after this issue, with source branch created from '#{@project.default_branch}'.
-          %li.divider.droplab-item-ignore
-        %li{ class: [!can_create_merge_request && 'droplab-item-selected'], role: 'button', data: {  value: 'create-branch', 'text' => 'Create a branch' } }
-          .menu-item
-            .icon-container
-              = icon('check')
-            .description
-              %strong Create a branch
-              %span
-                Creates a branch named after this issue, from '#{@project.default_branch}'.
+          %li.create-item.droplab-item-selected.droplab-item-ignore-hiding{ role: 'button', data: { value: 'create-mr', text: 'Create merge request' } }
+            .menu-item.droplab-item-ignore-hiding
+              .icon-container.droplab-item-ignore-hiding= icon('check')
+              .description.droplab-item-ignore-hiding Create merge request and branch
+
+        %li.create-item.droplab-item-ignore-hiding{ class: [!can_create_merge_request && 'droplab-item-selected'], role: 'button', data: {  value: 'create-branch', text: 'Create branch' } }
+          .menu-item.droplab-item-ignore-hiding
+            .icon-container.droplab-item-ignore-hiding= icon('check')
+            .description.droplab-item-ignore-hiding Create branch
+        %li.divider
+
+        %li.droplab-item-ignore
+          Branch name
+          %input.js-branch-name.form-control.droplab-item-ignore{ type: 'text', placeholder: "#{@issue.to_branch_name}", value: "#{@issue.to_branch_name}" }
+          %span.js-branch-message.branch-message.droplab-item-ignore
+
+        %li.droplab-item-ignore
+          Source (branch or tag)
+          %input.js-ref.ref.form-control.droplab-item-ignore{ type: 'text', placeholder: "#{@project.default_branch}", value: "#{@project.default_branch}", data: { value: "#{@project.default_branch}" } }
+          %span.js-ref-message.ref-message.droplab-item-ignore
+
+        %li.droplab-item-ignore
+          %button.btn.btn-success.js-create-target.droplab-item-ignore{ type: 'button', data: { action: 'create-mr' } }
+            Create merge request
+
diff --git a/changelogs/unreleased/21143-customize-branch-name-when-using-create-branch-in-an-issue.yml b/changelogs/unreleased/21143-customize-branch-name-when-using-create-branch-in-an-issue.yml
new file mode 100644
index 00000000000..d4c209aaf2b
--- /dev/null
+++ b/changelogs/unreleased/21143-customize-branch-name-when-using-create-branch-in-an-issue.yml
@@ -0,0 +1,5 @@
+---
+title: Add an ability to use a custom branch name on creation from issues
+merge_request: 13884
+author: Vitaliy @blackst0ne Klachkov
+type: added
diff --git a/spec/features/issues/create_branch_merge_request_spec.rb b/spec/features/issues/create_branch_merge_request_spec.rb
deleted file mode 100644
index edea95c6699..00000000000
--- a/spec/features/issues/create_branch_merge_request_spec.rb
+++ /dev/null
@@ -1,106 +0,0 @@
-require 'rails_helper'
-
-feature 'Create Branch/Merge Request Dropdown on issue page', :feature, :js do
-  let(:user) { create(:user) }
-  let!(:project) { create(:project, :repository) }
-  let(:issue) { create(:issue, project: project, title: 'Cherry-Coloured Funk') }
-
-  context 'for team members' do
-    before do
-      project.team << [user, :developer]
-      sign_in(user)
-    end
-
-    it 'allows creating a merge request from the issue page' do
-      visit project_issue_path(project, issue)
-
-      perform_enqueued_jobs do
-        select_dropdown_option('create-mr')
-
-        expect(page).to have_content('WIP: Resolve "Cherry-Coloured Funk"')
-        expect(current_path).to eq(project_merge_request_path(project, MergeRequest.first))
-
-        wait_for_requests
-      end
-
-      visit project_issue_path(project, issue)
-
-      expect(page).to have_content("created branch 1-cherry-coloured-funk")
-      expect(page).to have_content("mentioned in merge request !1")
-    end
-
-    it 'allows creating a branch from the issue page' do
-      visit project_issue_path(project, issue)
-
-      select_dropdown_option('create-branch')
-
-      wait_for_requests
-
-      expect(page).to have_selector('.dropdown-toggle-text ', text: '1-cherry-coloured-funk')
-      expect(current_path).to eq project_tree_path(project, '1-cherry-coloured-funk')
-    end
-
-    context "when there is a referenced merge request" do
-      let!(:note) do
-        create(:note, :on_issue, :system, project: project, noteable: issue,
-                                          note: "mentioned in #{referenced_mr.to_reference}")
-      end
-
-      let(:referenced_mr) do
-        create(:merge_request, :simple, source_project: project, target_project: project,
-                                        description: "Fixes #{issue.to_reference}", author: user)
-      end
-
-      before do
-        referenced_mr.cache_merge_request_closes_issues!(user)
-
-        visit project_issue_path(project, issue)
-      end
-
-      it 'disables the create branch button' do
-        expect(page).to have_css('.create-mr-dropdown-wrap .unavailable:not(.hide)')
-        expect(page).to have_css('.create-mr-dropdown-wrap .available.hide', visible: false)
-        expect(page).to have_content /1 Related Merge Request/
-      end
-    end
-
-    context 'when merge requests are disabled' do
-      before do
-        project.project_feature.update(merge_requests_access_level: 0)
-
-        visit project_issue_path(project, issue)
-      end
-
-      it 'shows only create branch button' do
-        expect(page).not_to have_button('Create a merge request')
-        expect(page).to have_button('Create a branch')
-      end
-    end
-
-    context 'when issue is confidential' do
-      it 'disables the create branch button' do
-        issue = create(:issue, :confidential, project: project)
-
-        visit project_issue_path(project, issue)
-
-        expect(page).not_to have_css('.create-mr-dropdown-wrap')
-      end
-    end
-  end
-
-  context 'for visitors' do
-    before do
-      visit project_issue_path(project, issue)
-    end
-
-    it 'shows no buttons' do
-      expect(page).not_to have_selector('.create-mr-dropdown-wrap')
-    end
-  end
-
-  def select_dropdown_option(option)
-    find('.create-mr-dropdown-wrap .dropdown-toggle').click
-    find("li[data-value='#{option}']").click
-    find('.js-create-merge-request').click
-  end
-end
diff --git a/spec/features/issues/user_creates_branch_and_merge_request_spec.rb b/spec/features/issues/user_creates_branch_and_merge_request_spec.rb
new file mode 100644
index 00000000000..539d7e9ff01
--- /dev/null
+++ b/spec/features/issues/user_creates_branch_and_merge_request_spec.rb
@@ -0,0 +1,248 @@
+require 'rails_helper'
+
+describe 'User creates branch and merge request on issue page', :js do
+  let(:user) { create(:user) }
+  let!(:project) { create(:project, :repository) }
+  let(:issue) { create(:issue, project: project, title: 'Cherry-Coloured Funk') }
+
+  context 'when signed out' do
+    before do
+      visit project_issue_path(project, issue)
+    end
+
+    it "doesn't show 'Create merge request' button" do
+      expect(page).not_to have_selector('.create-mr-dropdown-wrap')
+    end
+  end
+
+  context 'when signed in' do
+    before do
+      project.add_developer(user)
+
+      sign_in(user)
+    end
+
+    context 'when interacting with the dropdown' do
+      before do
+        visit project_issue_path(project, issue)
+      end
+
+      # In order to improve tests performance, all UI checks are placed in this test.
+      it 'shows elements' do
+        button_create_merge_request = find('.js-create-merge-request')
+        button_toggle_dropdown = find('.create-mr-dropdown-wrap .dropdown-toggle')
+
+        button_toggle_dropdown.click
+
+        dropdown = find('.create-merge-request-dropdown-menu')
+
+        page.within(dropdown) do
+          button_create_target = find('.js-create-target')
+          input_branch_name = find('.js-branch-name')
+          input_source = find('.js-ref')
+          li_create_branch = find("li[data-value='create-branch']")
+          li_create_merge_request = find("li[data-value='create-mr']")
+
+          # Test that all elements are presented.
+          expect(page).to have_content('Create merge request and branch')
+          expect(page).to have_content('Create branch')
+          expect(page).to have_content('Branch name')
+          expect(page).to have_content('Source (branch or tag)')
+          expect(page).to have_button('Create merge request')
+          expect(page).to have_selector('.js-branch-name:focus')
+
+          test_selection_mark(li_create_branch, li_create_merge_request, button_create_target, button_create_merge_request)
+          test_branch_name_checking(input_branch_name)
+          test_source_checking(input_source)
+
+          # The button inside dropdown should be disabled if any errors occured.
+          expect(page).to have_button('Create branch', disabled: true)
+        end
+
+        # The top level button should be disabled if any errors occured.
+        expect(page).to have_button('Create branch', disabled: true)
+      end
+
+      context 'when branch name is auto-generated' do
+        it 'creates a merge request' do
+          perform_enqueued_jobs do
+            select_dropdown_option('create-mr')
+
+            expect(page).to have_content('WIP: Resolve "Cherry-Coloured Funk"')
+            expect(current_path).to eq(project_merge_request_path(project, MergeRequest.first))
+
+            wait_for_requests
+          end
+
+          visit project_issue_path(project, issue)
+
+          expect(page).to have_content('created branch 1-cherry-coloured-funk')
+          expect(page).to have_content('mentioned in merge request !1')
+        end
+
+        it 'creates a branch' do
+          select_dropdown_option('create-branch')
+
+          wait_for_requests
+
+          expect(page).to have_selector('.dropdown-toggle-text ', text: '1-cherry-coloured-funk')
+          expect(current_path).to eq project_tree_path(project, '1-cherry-coloured-funk')
+        end
+      end
+
+      context 'when branch name is custom' do
+        let(:branch_name) { 'custom-branch-name' }
+
+        it 'creates a merge request' do
+          perform_enqueued_jobs do
+            select_dropdown_option('create-mr', branch_name)
+
+            expect(page).to have_content('WIP: Resolve "Cherry-Coloured Funk"')
+            expect(page).to have_content('Request to merge custom-branch-name into')
+            expect(current_path).to eq(project_merge_request_path(project, MergeRequest.first))
+
+            wait_for_requests
+          end
+
+          visit project_issue_path(project, issue)
+
+          expect(page).to have_content('created branch custom-branch-name')
+          expect(page).to have_content('mentioned in merge request !1')
+        end
+
+        it 'creates a branch' do
+          select_dropdown_option('create-branch', branch_name)
+
+          wait_for_requests
+
+          expect(page).to have_selector('.dropdown-toggle-text ', text: branch_name)
+          expect(current_path).to eq project_tree_path(project, branch_name)
+        end
+      end
+    end
+
+    context "when there is a referenced merge request" do
+      let!(:note) do
+        create(:note, :on_issue, :system, project: project, noteable: issue,
+                                          note: "mentioned in #{referenced_mr.to_reference}")
+      end
+
+      let(:referenced_mr) do
+        create(:merge_request, :simple, source_project: project, target_project: project,
+                                        description: "Fixes #{issue.to_reference}", author: user)
+      end
+
+      before do
+        referenced_mr.cache_merge_request_closes_issues!(user)
+
+        visit project_issue_path(project, issue)
+      end
+
+      it 'disables the create branch button' do
+        expect(page).to have_css('.create-mr-dropdown-wrap .unavailable:not(.hide)')
+        expect(page).to have_css('.create-mr-dropdown-wrap .available.hide', visible: false)
+        expect(page).to have_content /1 Related Merge Request/
+      end
+    end
+
+    context 'when merge requests are disabled' do
+      before do
+        project.project_feature.update(merge_requests_access_level: 0)
+
+        visit project_issue_path(project, issue)
+      end
+
+      it 'shows only create branch button' do
+        expect(page).not_to have_button('Create merge request')
+        expect(page).to have_button('Create branch')
+      end
+    end
+
+    context 'when issue is confidential' do
+      let(:issue) { create(:issue, :confidential, project: project) }
+
+      it 'disables the create branch button' do
+        visit project_issue_path(project, issue)
+
+        expect(page).not_to have_css('.create-mr-dropdown-wrap')
+      end
+    end
+  end
+
+  private
+
+  def select_dropdown_option(option, branch_name = nil)
+    find('.create-mr-dropdown-wrap .dropdown-toggle').click
+    find("li[data-value='#{option}']").click
+
+    if branch_name
+      find('.js-branch-name').set(branch_name)
+
+      # Javascript debounces AJAX calls.
+      # So we have to wait until AJAX requests are started.
+      # Details are in app/assets/javascripts/create_merge_request_dropdown.js
+      # this.refDebounce = _.debounce(...)
+      sleep 0.5
+
+      wait_for_requests
+    end
+
+    find('.js-create-merge-request').click
+  end
+
+  def test_branch_name_checking(input_branch_name)
+    expect(input_branch_name.value).to eq(issue.to_branch_name)
+
+    input_branch_name.set('new-branch-name')
+    branch_name_message = find('.js-branch-message')
+
+    expect(branch_name_message).to have_text('Checking branch name availability…')
+
+    wait_for_requests
+
+    expect(branch_name_message).to have_text('Branch name is available')
+
+    input_branch_name.set(project.default_branch)
+
+    expect(branch_name_message).to have_text('Checking branch name availability…')
+
+    wait_for_requests
+
+    expect(branch_name_message).to have_text('Branch is already taken')
+  end
+
+  def test_selection_mark(li_create_branch, li_create_merge_request, button_create_target, button_create_merge_request)
+    page.within(li_create_merge_request) do
+      expect(page).to have_css('i.fa.fa-check')
+      expect(button_create_target).to have_text('Create merge request')
+      expect(button_create_merge_request).to have_text('Create merge request')
+    end
+
+    li_create_branch.click
+
+    page.within(li_create_branch) do
+      expect(page).to have_css('i.fa.fa-check')
+      expect(button_create_target).to have_text('Create branch')
+      expect(button_create_merge_request).to have_text('Create branch')
+    end
+  end
+
+  def test_source_checking(input_source)
+    expect(input_source.value).to eq(project.default_branch)
+
+    input_source.set('mas') # Intentionally entered first 3 letters of `master` to check autocomplete feature later.
+    source_message = find('.js-ref-message')
+
+    expect(source_message).to have_text('Checking source availability…')
+
+    wait_for_requests
+
+    expect(source_message).to have_text('Source is not available')
+
+    # JavaScript gets refs started with `mas` (entered above) and places the first match.
+    # User sees `mas` in black color (the part he entered) and the `ter` in gray color (a hint).
+    # Since hinting is implemented via text selection and rspec/capybara doesn't have matchers for it,
+    # we just checking the whole source name.
+    expect(input_source.value).to eq(project.default_branch)
+  end
+end
diff --git a/spec/javascripts/droplab/drop_down_spec.js b/spec/javascripts/droplab/drop_down_spec.js
index 1ef494a00b8..1225fe2cb66 100644
--- a/spec/javascripts/droplab/drop_down_spec.js
+++ b/spec/javascripts/droplab/drop_down_spec.js
@@ -279,7 +279,12 @@ describe('DropDown', function () {
   describe('addEvents', function () {
     beforeEach(function () {
       this.list = { addEventListener: () => {} };
-      this.dropdown = { list: this.list, clickEvent: () => {}, eventWrapper: {} };
+      this.dropdown = {
+        list: this.list,
+        clickEvent: () => {},
+        closeDropdown: () => {},
+        eventWrapper: {},
+      };
 
       spyOn(this.list, 'addEventListener');
 
@@ -288,6 +293,7 @@ describe('DropDown', function () {
 
     it('should call .addEventListener', function () {
       expect(this.list.addEventListener).toHaveBeenCalledWith('click', jasmine.any(Function));
+      expect(this.list.addEventListener).toHaveBeenCalledWith('keyup', jasmine.any(Function));
     });
   });
 
diff --git a/spec/javascripts/droplab/hook_spec.js b/spec/javascripts/droplab/hook_spec.js
index 75bf5f3d611..3d39bd0812b 100644
--- a/spec/javascripts/droplab/hook_spec.js
+++ b/spec/javascripts/droplab/hook_spec.js
@@ -24,7 +24,7 @@ describe('Hook', function () {
     });
 
     it('should call DropDown constructor', function () {
-      expect(dropdownSrc.default).toHaveBeenCalledWith(this.list);
+      expect(dropdownSrc.default).toHaveBeenCalledWith(this.list, this.config);
     });
 
     it('should set .type', function () {
diff --git a/spec/services/merge_requests/create_from_issue_service_spec.rb b/spec/services/merge_requests/create_from_issue_service_spec.rb
index 313f87ae1f6..a7ab389b357 100644
--- a/spec/services/merge_requests/create_from_issue_service_spec.rb
+++ b/spec/services/merge_requests/create_from_issue_service_spec.rb
@@ -6,8 +6,10 @@ describe MergeRequests::CreateFromIssueService do
   let(:label_ids) { create_pair(:label, project: project).map(&:id) }
   let(:milestone_id) { create(:milestone, project: project).id }
   let(:issue) { create(:issue, project: project, milestone_id: milestone_id) }
+  let(:custom_source_branch) { 'custom-source-branch' }
 
   subject(:service) { described_class.new(project, user, issue_iid: issue.iid) }
+  subject(:service_with_custom_source_branch) { described_class.new(project, user, issue_iid: issue.iid, branch_name: custom_source_branch) }
 
   before do
     project.add_developer(user)
@@ -17,8 +19,8 @@ describe MergeRequests::CreateFromIssueService do
     it 'returns an error with invalid issue iid' do
       result = described_class.new(project, user, issue_iid: -1).execute
 
-      expect(result[:status]).to eq :error
-      expect(result[:message]).to eq 'Invalid issue iid'
+      expect(result[:status]).to eq(:error)
+      expect(result[:message]).to eq('Invalid issue iid')
     end
 
     it 'delegates issue search to IssuesFinder' do
@@ -53,6 +55,12 @@ describe MergeRequests::CreateFromIssueService do
       expect(project.repository.branch_exists?(issue.to_branch_name)).to be_truthy
     end
 
+    it 'creates a branch using passed name' do
+      service_with_custom_source_branch.execute
+
+      expect(project.repository.branch_exists?(custom_source_branch)).to be_truthy
+    end
+
     it 'creates a system note' do
       expect(SystemNoteService).to receive(:new_issue_branch).with(issue, project, user, issue.to_branch_name)
 
@@ -72,19 +80,25 @@ describe MergeRequests::CreateFromIssueService do
     it 'sets the merge request author to current user' do
       result = service.execute
 
-      expect(result[:merge_request].author).to eq user
+      expect(result[:merge_request].author).to eq(user)
     end
 
     it 'sets the merge request source branch to the new issue branch' do
       result = service.execute
 
-      expect(result[:merge_request].source_branch).to eq issue.to_branch_name
+      expect(result[:merge_request].source_branch).to eq(issue.to_branch_name)
+    end
+
+    it 'sets the merge request source branch to the passed branch name' do
+      result = service_with_custom_source_branch.execute
+
+      expect(result[:merge_request].source_branch).to eq(custom_source_branch)
     end
 
     it 'sets the merge request target branch to the project default branch' do
       result = service.execute
 
-      expect(result[:merge_request].target_branch).to eq project.default_branch
+      expect(result[:merge_request].target_branch).to eq(project.default_branch)
     end
   end
 end