Add MR form to runtime Visual Review configuration

* adds the ability to enter a merge request ID directly into the toolbar,
* adds the option to save the ID to `localStorage` (as with the token),
* adds a link to change the ID once entered
* adds some more explanatory errors for 401 & 404
* saves the comment to session storage if the user navigates away without posting it

app/assets/javascripts/visual_review_toolbar/components/comment.js

-import { BLACK, COMMENT_BOX, MUTED, LOGOUT } from './constants';
-import { clearNote, postError } from './note';
-import {
-  buttonClearStyles,
-  selectCommentBox,
-  selectCommentButton,
-  selectNote,
-  selectNoteContainer,
-} from './utils';
-
-const comment = `
-  <div>
-    <textarea id="${COMMENT_BOX}" name="${COMMENT_BOX}" rows="3" placeholder="Enter your feedback or idea" class="gitlab-input" aria-required="true"></textarea>
-    <p class="gitlab-metadata-note">Additional metadata will be included: browser, OS, current page, user agent, and viewport dimensions.</p>
-  </div>
-  <div class="gitlab-button-wrapper">
-    <button class="gitlab-button gitlab-button-secondary" style="${buttonClearStyles}" type="button" id="${LOGOUT}"> Log out </button>
-    <button class="gitlab-button gitlab-button-success" style="${buttonClearStyles}" type="button" id="gitlab-comment-button"> Send feedback </button>
-  </div>
-`;
-
-const resetCommentButton = () => {
-  const commentButton = selectCommentButton();
-
-  /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
-  commentButton.innerText = 'Send feedback';
-  commentButton.classList.replace('gitlab-button-secondary', 'gitlab-button-success');
-  commentButton.style.opacity = 1;
-};
-
-const resetCommentBox = () => {
-  const commentBox = selectCommentBox();
-  commentBox.style.pointerEvents = 'auto';
-  commentBox.style.color = BLACK;
-};
-
-const resetCommentText = () => {
-  const commentBox = selectCommentBox();
-  commentBox.value = '';
-};
-
-const resetComment = () => {
-  resetCommentButton();
-  resetCommentBox();
-  resetCommentText();
-};
-
-const confirmAndClear = feedbackInfo => {
-  const commentButton = selectCommentButton();
-  const currentNote = selectNote();
-  const noteContainer = selectNoteContainer();
-
-  /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
-  commentButton.innerText = 'Feedback sent';
-  noteContainer.style.visibility = 'visible';
-  currentNote.insertAdjacentHTML('beforeend', feedbackInfo);
-
-  setTimeout(resetComment, 1000);
-  setTimeout(clearNote, 6000);
-};
-
-const setInProgressState = () => {
-  const commentButton = selectCommentButton();
-  const commentBox = selectCommentBox();
-
-  /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
-  commentButton.innerText = 'Sending feedback';
-  commentButton.classList.replace('gitlab-button-success', 'gitlab-button-secondary');
-  commentButton.style.opacity = 0.5;
-  commentBox.style.color = MUTED;
-  commentBox.style.pointerEvents = 'none';
-};
-
-const postComment = ({
-  href,
-  platform,
-  browser,
-  userAgent,
-  innerWidth,
-  innerHeight,
-  projectId,
-  projectPath,
-  mergeRequestId,
-  mrUrl,
-  token,
-}) => {
-  // Clear any old errors
-  clearNote(COMMENT_BOX);
-
-  setInProgressState();
-
-  const commentText = selectCommentBox().value.trim();
-
-  if (!commentText) {
-    /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
-    postError('Your comment appears to be empty.', COMMENT_BOX);
-    resetCommentBox();
-    resetCommentButton();
-    return;
-  }
-
-  const detailText = `
- \n
-<details>
-  <summary>Metadata</summary>
-  Posted from ${href} | ${platform} | ${browser} | ${innerWidth} x ${innerHeight}.
-  <br /><br />
-  <em>User agent: ${userAgent}</em>
-</details>
+import { nextView } from '../store';
+import { localStorage, COMMENT_BOX, LOGOUT } from '../shared';
+import { clearNote } from './note';
+import { buttonClearStyles } from './utils';
+import { addForm } from './wrapper';
+import { changeSelectedMr, selectedMrNote } from './comment_mr_note';
+import postComment from './comment_post';
+import { saveComment, getSavedComment } from './comment_storage';
+
+const comment = state => {
+  const savedComment = getSavedComment();
+
+  return `
+    <div>
+      <textarea id="${COMMENT_BOX}" name="${COMMENT_BOX}" rows="3" placeholder="Enter your feedback or idea" class="gitlab-input" aria-required="true">${savedComment}</textarea>
+      ${selectedMrNote(state)}
+      <p class="gitlab-metadata-note">Additional metadata will be included: browser, OS, current page, user agent, and viewport dimensions.</p>
+    </div>
+    <div class="gitlab-button-wrapper">
+      <button class="gitlab-button gitlab-button-success" style="${buttonClearStyles}" type="button" id="gitlab-comment-button"> Send feedback </button>
+      <button class="gitlab-button gitlab-button-secondary" style="${buttonClearStyles}" type="button" id="${LOGOUT}"> Log out </button>
+    </div>
   `;
+};
 
-  const url = `
-    ${mrUrl}/api/v4/projects/${projectId}/merge_requests/${mergeRequestId}/discussions`;
-
-  const body = `${commentText} ${detailText}`;
-
-  fetch(url, {
-    method: 'POST',
-    headers: {
-      'PRIVATE-TOKEN': token,
-      'Content-Type': 'application/json',
-    },
-    body: JSON.stringify({ body }),
-  })
-    .then(response => {
-      if (response.ok) {
-        return response.json();
-      }
-
-      throw new Error(`${response.status}: ${response.statusText}`);
-    })
-    .then(data => {
-      const commentId = data.notes[0].id;
-      const feedbackLink = `${mrUrl}/${projectPath}/merge_requests/${mergeRequestId}#note_${commentId}`;
-      const feedbackInfo = `Feedback sent. View at <a class="gitlab-link" href="${feedbackLink}">${projectPath} #${mergeRequestId} (comment ${commentId})</a>`;
-      confirmAndClear(feedbackInfo);
-    })
-    .catch(err => {
-      postError(
-        `Your comment could not be sent. Please try again. Error: ${err.message}`,
-        COMMENT_BOX,
-      );
-      resetCommentBox();
-      resetCommentButton();
-    });
+// This function is here becaause it is called only from the comment view
+// If we reach a design where we can logout from multiple views, promote this
+// to it's own package
+const logoutUser = state => {
+  localStorage.removeItem('token');
+  localStorage.removeItem('mergeRequestId');
+  state.token = '';
+  state.mergeRequestId = '';
+
+  clearNote();
+  addForm(nextView(state, COMMENT_BOX));
 };
 
-export { comment, postComment };
+export { changeSelectedMr, comment, logoutUser, postComment, saveComment };

app/assets/javascripts/visual_review_toolbar/components/comment_mr_note.js

+import { nextView } from '../store';
+import { localStorage, CHANGE_MR_ID_BUTTON, COMMENT_BOX } from '../shared';
+import { clearNote } from './note';
+import { buttonClearStyles } from './utils';
+import { addForm } from './wrapper';
+
+const selectedMrNote = state => {
+  const { mrUrl, projectPath, mergeRequestId } = state;
+
+  const mrLink = `${mrUrl}/${projectPath}/merge_requests/${mergeRequestId}`;
+
+  return `
+    <p class="gitlab-metadata-note">
+      This posts to merge request <a class="gitlab-link" href="${mrLink}">!${mergeRequestId}</a>.
+      <button style="${buttonClearStyles}" type="button" id="${CHANGE_MR_ID_BUTTON}" class="gitlab-link gitlab-link-button">Change</button>
+    </p>
+  `;
+};
+
+const clearMrId = state => {
+  localStorage.removeItem('mergeRequestId');
+  state.mergeRequestId = '';
+};
+
+const changeSelectedMr = state => {
+  clearMrId(state);
+  clearNote();
+  addForm(nextView(state, COMMENT_BOX));
+};
+
+export { changeSelectedMr, selectedMrNote };

app/assets/javascripts/visual_review_toolbar/components/comment_post.js

+import { BLACK, COMMENT_BOX, MUTED } from '../shared';
+import { clearSavedComment } from './comment_storage';
+import { clearNote, postError } from './note';
+import { selectCommentBox, selectCommentButton, selectNote, selectNoteContainer } from './utils';
+
+const resetCommentButton = () => {
+  const commentButton = selectCommentButton();
+
+  /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+  commentButton.innerText = 'Send feedback';
+  commentButton.classList.replace('gitlab-button-secondary', 'gitlab-button-success');
+  commentButton.style.opacity = 1;
+};
+
+const resetCommentBox = () => {
+  const commentBox = selectCommentBox();
+  commentBox.style.pointerEvents = 'auto';
+  commentBox.style.color = BLACK;
+};
+
+const resetCommentText = () => {
+  const commentBox = selectCommentBox();
+  commentBox.value = '';
+  clearSavedComment();
+};
+
+const resetComment = () => {
+  resetCommentButton();
+  resetCommentBox();
+  resetCommentText();
+};
+
+const confirmAndClear = feedbackInfo => {
+  const commentButton = selectCommentButton();
+  const currentNote = selectNote();
+  const noteContainer = selectNoteContainer();
+
+  /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+  commentButton.innerText = 'Feedback sent';
+  noteContainer.style.visibility = 'visible';
+  currentNote.insertAdjacentHTML('beforeend', feedbackInfo);
+
+  setTimeout(resetComment, 1000);
+  setTimeout(clearNote, 6000);
+};
+
+const setInProgressState = () => {
+  const commentButton = selectCommentButton();
+  const commentBox = selectCommentBox();
+
+  /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+  commentButton.innerText = 'Sending feedback';
+  commentButton.classList.replace('gitlab-button-success', 'gitlab-button-secondary');
+  commentButton.style.opacity = 0.5;
+  commentBox.style.color = MUTED;
+  commentBox.style.pointerEvents = 'none';
+};
+
+const commentErrors = error => {
+  switch (error.status) {
+    case 401:
+      /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+      return 'Unauthorized. You may have entered an incorrect authentication token.';
+    case 404:
+      /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+      return 'Not found. You may have entered an incorrect merge request ID.';
+    default:
+      /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+      return `Your comment could not be sent. Please try again. Error: ${error.message}`;
+  }
+};
+
+const postComment = ({
+  platform,
+  browser,
+  userAgent,
+  innerWidth,
+  innerHeight,
+  projectId,
+  projectPath,
+  mergeRequestId,
+  mrUrl,
+  token,
+}) => {
+  // Clear any old errors
+  clearNote(COMMENT_BOX);
+
+  setInProgressState();
+
+  const commentText = selectCommentBox().value.trim();
+  // Get the href at the last moment to support SPAs
+  const { href } = window.location;
+
+  if (!commentText) {
+    /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+    postError('Your comment appears to be empty.', COMMENT_BOX);
+    resetCommentBox();
+    resetCommentButton();
+    return;
+  }
+
+  const detailText = `
+ \n
+<details>
+  <summary>Metadata</summary>
+  Posted from ${href} | ${platform} | ${browser} | ${innerWidth} x ${innerHeight}.
+  <br /><br />
+  <em>User agent: ${userAgent}</em>
+</details>
+  `;
+
+  const url = `
+    ${mrUrl}/api/v4/projects/${projectId}/merge_requests/${mergeRequestId}/discussions`;
+
+  const body = `${commentText} ${detailText}`;
+
+  fetch(url, {
+    method: 'POST',
+    headers: {
+      'PRIVATE-TOKEN': token,
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({ body }),
+  })
+    .then(response => {
+      if (response.ok) {
+        return response.json();
+      }
+
+      throw response;
+    })
+    .then(data => {
+      const commentId = data.notes[0].id;
+      const feedbackLink = `${mrUrl}/${projectPath}/merge_requests/${mergeRequestId}#note_${commentId}`;
+      const feedbackInfo = `Feedback sent. View at <a class="gitlab-link" href="${feedbackLink}">${projectPath} !${mergeRequestId} (comment ${commentId})</a>`;
+      confirmAndClear(feedbackInfo);
+    })
+    .catch(err => {
+      postError(commentErrors(err), COMMENT_BOX);
+      resetCommentBox();
+      resetCommentButton();
+    });
+};
+
+export default postComment;

app/assets/javascripts/visual_review_toolbar/components/comment_storage.js

+import { selectCommentBox } from './utils';
+import { sessionStorage } from '../shared';
+
+const getSavedComment = () => sessionStorage.getItem('comment') || '';
+
+const saveComment = () => {
+  const currentComment = selectCommentBox();
+
+  // This may be added to any view via top-level beforeunload listener
+  // so let's skip if it does not apply
+  if (currentComment && currentComment.value) {
+    sessionStorage.setItem('comment', currentComment.value);
+  }
+};
+
+const clearSavedComment = () => {
+  sessionStorage.removeItem('comment');
+};
+
+export { getSavedComment, saveComment, clearSavedComment };

app/assets/javascripts/visual_review_toolbar/components/form_elements.js

+import { REMEMBER_ITEM } from '../shared';
+import { buttonClearStyles } from './utils';
+
+/* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+const rememberBox = (rememberText = 'Remember me') => `
+  <div class="gitlab-checkbox-wrapper">
+    <input type="checkbox" id="${REMEMBER_ITEM}" name="${REMEMBER_ITEM}" value="remember">
+    <label for="${REMEMBER_ITEM}" class="gitlab-checkbox-label">${rememberText}</label>
+  </div>
+`;
+
+const submitButton = buttonId => `
+  <div class="gitlab-button-wrapper">
+    <button class="gitlab-button-wide gitlab-button gitlab-button-success" style="${buttonClearStyles}" type="button" id="${buttonId}"> Submit </button>
+  </div>
+`;
+export { rememberBox, submitButton };

app/assets/javascripts/visual_review_toolbar/components/index.js

-import { comment, postComment } from './comment';
-import {
-  COLLAPSE_BUTTON,
-  COMMENT_BUTTON,
-  FORM_CONTAINER,
-  LOGIN,
-  LOGOUT,
-  REVIEW_CONTAINER,
-} from './constants';
+import { changeSelectedMr, comment, logoutUser, postComment, saveComment } from './comment';
 import { authorizeUser, login } from './login';
+import { addMr, mrForm } from './mr_id';
 import { note } from './note';
-import { selectContainer } from './utils';
-import { buttonAndForm, logoutUser, toggleForm } from './wrapper';
-import { collapseButton } from './wrapper_icons';
+import { selectContainer, selectForm } from './utils';
+import { buttonAndForm, toggleForm } from './wrapper';
 
 export {
+  addMr,
   authorizeUser,
   buttonAndForm,
-  collapseButton,
+  changeSelectedMr,
   comment,
   login,
   logoutUser,
+  mrForm,
   note,
   postComment,
+  saveComment,
   selectContainer,
+  selectForm,
   toggleForm,
-  COLLAPSE_BUTTON,
-  COMMENT_BUTTON,
-  FORM_CONTAINER,
-  LOGIN,
-  LOGOUT,
-  REVIEW_CONTAINER,
 };

app/assets/javascripts/visual_review_toolbar/components/login.js

-import { LOGIN, REMEMBER_TOKEN, TOKEN_BOX } from './constants';
+import { nextView } from '../store';
+import { localStorage, LOGIN, TOKEN_BOX } from '../shared';
 import { clearNote, postError } from './note';
-import { buttonClearStyles, selectRemember, selectToken } from './utils';
-import { addCommentForm } from './wrapper';
+import { rememberBox, submitButton } from './form_elements';
+import { selectRemember, selectToken } from './utils';
+import { addForm } from './wrapper';
+
+const labelText = `
+  Enter your <a class="gitlab-link" href="https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html">personal access token</a>
+`;
 
 const login = `
-  <div>
-    <label for="${TOKEN_BOX}" class="gitlab-label">Enter your <a class="gitlab-link" href="https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html">personal access token</a></label>
-    <input class="gitlab-input" type="password" id="${TOKEN_BOX}" name="${TOKEN_BOX}" aria-required="true" autocomplete="current-password">
-  </div>
-  <div class="gitlab-checkbox-wrapper">
-    <input type="checkbox" id="${REMEMBER_TOKEN}" name="${REMEMBER_TOKEN}" value="remember">
-    <label for="${REMEMBER_TOKEN}" class="gitlab-checkbox-label">Remember me</label>
-  </div>
-  <div class="gitlab-button-wrapper">
-    <button class="gitlab-button-wide gitlab-button gitlab-button-success" style="${buttonClearStyles}" type="button" id="${LOGIN}"> Submit </button>
-  </div>
+    <div>
+      <label for="${TOKEN_BOX}" class="gitlab-label">${labelText}</label>
+      <input class="gitlab-input" type="password" id="${TOKEN_BOX}" name="${TOKEN_BOX}" autocomplete="current-password" aria-required="true">
+    </div>
+    ${rememberBox()}
+    ${submitButton(LOGIN)}
 `;
 
 const storeToken = (token, state) => {
-  const { localStorage } = window;
   const rememberMe = selectRemember().checked;
 
-  // All the browsers we support have localStorage, so let's silently fail
-  // and go on with the rest of the functionality.
-  try {
-    if (rememberMe) {
-      localStorage.setItem('token', token);
-    }
-  } finally {
-    state.token = token;
+  if (rememberMe) {
+    localStorage.setItem('token', token);
   }
+
+  state.token = token;
 };
 
 const authorizeUser = state => {
@@ -45,7 +41,7 @@ const authorizeUser = state => {
   }
 
   storeToken(token, state);
-  addCommentForm();
+  addForm(nextView(state, LOGIN));
 };
 
-export { authorizeUser, login };
+export { authorizeUser, login, storeToken };

app/assets/javascripts/visual_review_toolbar/components/mr_id.js

+import { nextView } from '../store';
+import { MR_ID, MR_ID_BUTTON, localStorage } from '../shared';
+import { clearNote, postError } from './note';
+import { rememberBox, submitButton } from './form_elements';
+import { selectForm, selectMrBox, selectRemember } from './utils';
+import { addForm } from './wrapper';
+
+/* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+const mrLabel = `Enter your merge request ID`;
+/* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+const mrRememberText = `Remember this number`;
+
+const mrForm = `
+    <div>
+      <label for="${MR_ID}" class="gitlab-label">${mrLabel}</label>
+      <input class="gitlab-input" type="text" pattern="[1-9][0-9]*" id="${MR_ID}" name="${MR_ID}" placeholder="e.g., 321" aria-required="true">
+    </div>
+    ${rememberBox(mrRememberText)}
+    ${submitButton(MR_ID_BUTTON)}
+`;
+
+const storeMR = (id, state) => {
+  const rememberMe = selectRemember().checked;
+
+  if (rememberMe) {
+    localStorage.setItem('mergeRequestId', id);
+  }
+
+  state.mergeRequestId = id;
+};
+
+const getFormError = (mrNumber, form) => {
+  if (!mrNumber) {
+    /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+    return 'Please enter your merge request ID number.';
+  }
+
+  if (!form.checkValidity()) {
+    /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
+    return 'Please remove any non-number values from the field.';
+  }
+
+  return null;
+};
+
+const addMr = state => {
+  // Clear any old errors
+  clearNote(MR_ID);
+
+  const mrNumber = selectMrBox().value;
+  const form = selectForm();
+  const formError = getFormError(mrNumber, form);
+
+  if (formError) {
+    postError(formError, MR_ID);
+    return;
+  }
+
+  storeMR(mrNumber, state);
+  addForm(nextView(state, MR_ID));
+};
+
+export { addMr, mrForm, storeMR };

app/assets/javascripts/visual_review_toolbar/components/note.js

-import { NOTE, NOTE_CONTAINER, RED } from './constants';
+import { NOTE, NOTE_CONTAINER, RED } from '../shared';
 import { selectById, selectNote, selectNoteContainer } from './utils';
 
 const note = `

app/assets/javascripts/visual_review_toolbar/components/utils.js

@@ -6,12 +6,13 @@ import {
   COMMENT_BUTTON,
   FORM,
   FORM_CONTAINER,
+  MR_ID,
   NOTE,
   NOTE_CONTAINER,
-  REMEMBER_TOKEN,
+  REMEMBER_ITEM,
   REVIEW_CONTAINER,
   TOKEN_BOX,
-} from './constants';
+} from '../shared';
 
 // this style must be applied inline in a handful of components
 /* eslint-disable-next-line @gitlab/i18n/no-non-i18n-strings */
@@ -27,9 +28,10 @@ const selectCommentButton = () => document.getElementById(COMMENT_BUTTON);
 const selectContainer = () => document.getElementById(REVIEW_CONTAINER);
 const selectForm = () => document.getElementById(FORM);
 const selectFormContainer = () => document.getElementById(FORM_CONTAINER);
+const selectMrBox = () => document.getElementById(MR_ID);
 const selectNote = () => document.getElementById(NOTE);
 const selectNoteContainer = () => document.getElementById(NOTE_CONTAINER);
-const selectRemember = () => document.getElementById(REMEMBER_TOKEN);
+const selectRemember = () => document.getElementById(REMEMBER_ITEM);
 const selectToken = () => document.getElementById(TOKEN_BOX);
 
 export {
@@ -41,6 +43,7 @@ export {
   selectCommentButton,
   selectForm,
   selectFormContainer,
+  selectMrBox,
   selectNote,
   selectNoteContainer,
   selectRemember,

app/assets/javascripts/visual_review_toolbar/components/wrapper.js

-import { comment } from './comment';
-import { CLEAR, FORM, FORM_CONTAINER, WHITE } from './constants';
-import { login } from './login';
-import { clearNote } from './note';
+import { CLEAR, FORM, FORM_CONTAINER, WHITE } from '../shared';
 import {
   selectCollapseButton,
   selectForm,
   selectFormContainer,
   selectNoteContainer,
 } from './utils';
-import { commentIcon, compressIcon } from './wrapper_icons';
+import { collapseButton, commentIcon, compressIcon } from './wrapper_icons';
 
 const form = content => `
-  <form id="${FORM}">
+  <form id="${FORM}" novalidate>
     ${content}
   </form>
 `;
 
-const buttonAndForm = ({ content, toggleButton }) => `
+const buttonAndForm = content => `
   <div id="${FORM_CONTAINER}" class="gitlab-form-open">
-    ${toggleButton}
+    ${collapseButton}
     ${form(content)}
   </div>
 `;
 
-const addCommentForm = () => {
+const addForm = nextForm => {
   const formWrapper = selectForm();
-  formWrapper.innerHTML = comment;
+  formWrapper.innerHTML = nextForm;
 };
 
-const addLoginForm = () => {
-  const formWrapper = selectForm();
-  formWrapper.innerHTML = login;
-};
-
-function logoutUser() {
-  const { localStorage } = window;
-
-  // All the browsers we support have localStorage, so let's silently fail
-  // and go on with the rest of the functionality.
-  try {
-    localStorage.removeItem('token');
-  } catch (err) {
-    return;
-  }
-
-  clearNote();
-  addLoginForm();
-}
-
 function toggleForm() {
-  const collapseButton = selectCollapseButton();
+  const toggleButton = selectCollapseButton();
   const currentForm = selectForm();
   const formContainer = selectFormContainer();
   const noteContainer = selectNoteContainer();
@@ -84,19 +61,19 @@ function toggleForm() {
     },
   };
 
-  const nextState = collapseButton.classList.contains('gitlab-collapse-open') ? CLOSED : OPEN;
+  const nextState = toggleButton.classList.contains('gitlab-collapse-open') ? CLOSED : OPEN;
   const currentVals = stateVals[nextState];
 
   formContainer.classList.replace(...currentVals.containerClasses);
   formContainer.style.backgroundColor = currentVals.backgroundColor;
   formContainer.classList.toggle('gitlab-form-open');
   currentForm.style.display = currentVals.display;
-  collapseButton.classList.replace(...currentVals.buttonClasses);
-  collapseButton.innerHTML = currentVals.icon;
+  toggleButton.classList.replace(...currentVals.buttonClasses);
+  toggleButton.innerHTML = currentVals.icon;
 
   if (noteContainer && noteContainer.innerText.length > 0) {
     noteContainer.style.display = currentVals.display;
   }
 }
 
-export { addCommentForm, addLoginForm, buttonAndForm, logoutUser, toggleForm };
+export { addForm, buttonAndForm, toggleForm };

app/assets/javascripts/visual_review_toolbar/index.js

 import './styles/toolbar.css';
 
-import { buttonAndForm, note, selectContainer, REVIEW_CONTAINER } from './components';
-import { debounce, eventLookup, getInitialView, initializeState, updateWindowSize } from './store';
+import { buttonAndForm, note, selectForm, selectContainer } from './components';
+import { REVIEW_CONTAINER } from './shared';
+import { eventLookup, getInitialView, initializeGlobalListeners, initializeState } from './store';
 
 /*
 
@@ -20,7 +21,7 @@ import { debounce, eventLookup, getInitialView, initializeState, updateWindowSiz
 window.addEventListener('load', () => {
   initializeState(window, document);
 
-  const mainContent = buttonAndForm(getInitialView(window));
+  const mainContent = buttonAndForm(getInitialView());
   const container = document.createElement('div');
   container.setAttribute('id', REVIEW_CONTAINER);
   container.insertAdjacentHTML('beforeend', note);
@@ -29,8 +30,22 @@ window.addEventListener('load', () => {
   document.body.insertBefore(container, document.body.firstChild);
 
   selectContainer().addEventListener('click', event => {
-    eventLookup(event)();
+    eventLookup(event.target.id)();
   });
 
-  window.addEventListener('resize', debounce(updateWindowSize.bind(null, window), 200));
+  selectForm().addEventListener('submit', event => {
+    // this is important to prevent the form from adding data
+    // as URL params and inadvertently revealing secrets
+    event.preventDefault();
+
+    const id =
+      event.target.querySelector('.gitlab-button-wrapper') &&
+      event.target.querySelector('.gitlab-button-wrapper').getElementsByTagName('button')[0] &&
+      event.target.querySelector('.gitlab-button-wrapper').getElementsByTagName('button')[0].id;
+
+    // even if this is called with false, it's ok; it will get the default no-op
+    eventLookup(id)();
+  });
+
+  initializeGlobalListeners();
 });

app/assets/javascripts/visual_review_toolbar/components/constants.js → app/assets/javascripts/visual_review_toolbar/shared/constants.js

 // component selectors
+const CHANGE_MR_ID_BUTTON = 'gitlab-change-mr';
 const COLLAPSE_BUTTON = 'gitlab-collapse';
 const COMMENT_BOX = 'gitlab-comment';
 const COMMENT_BUTTON = 'gitlab-comment-button';
 const FORM = 'gitlab-form';
 const FORM_CONTAINER = 'gitlab-form-wrapper';
-const LOGIN = 'gitlab-login';
+const LOGIN = 'gitlab-login-button';
 const LOGOUT = 'gitlab-logout-button';
+const MR_ID = 'gitlab-submit-mr';
+const MR_ID_BUTTON = 'gitlab-submit-mr-button';
 const NOTE = 'gitlab-validation-note';
 const NOTE_CONTAINER = 'gitlab-note-wrapper';
-const REMEMBER_TOKEN = 'gitlab-remember_token';
+const REMEMBER_ITEM = 'gitlab-remember-item';
 const REVIEW_CONTAINER = 'gitlab-review-container';
 const TOKEN_BOX = 'gitlab-token';
 
@@ -21,6 +24,7 @@ const RED = 'rgba(219, 59, 33, 1)';
 const WHITE = 'rgba(250, 250, 250, 1)';
 
 export {
+  CHANGE_MR_ID_BUTTON,
   COLLAPSE_BUTTON,
   COMMENT_BOX,
   COMMENT_BUTTON,
@@ -28,9 +32,11 @@ export {
   FORM_CONTAINER,
   LOGIN,
   LOGOUT,
+  MR_ID,
+  MR_ID_BUTTON,
   NOTE,
   NOTE_CONTAINER,
-  REMEMBER_TOKEN,
+  REMEMBER_ITEM,
   REVIEW_CONTAINER,
   TOKEN_BOX,
   BLACK,

app/assets/javascripts/visual_review_toolbar/shared/index.js

+import {
+  CHANGE_MR_ID_BUTTON,
+  COLLAPSE_BUTTON,
+  COMMENT_BOX,
+  COMMENT_BUTTON,
+  FORM,
+  FORM_CONTAINER,
+  LOGIN,
+  LOGOUT,
+  MR_ID,
+  MR_ID_BUTTON,
+  NOTE,
+  NOTE_CONTAINER,
+  REMEMBER_ITEM,
+  REVIEW_CONTAINER,
+  TOKEN_BOX,
+  BLACK,
+  CLEAR,
+  MUTED,
+  RED,
+  WHITE,
+} from './constants';
+
+import { localStorage, sessionStorage } from './storage_utils';
+
+export {
+  localStorage,
+  sessionStorage,
+  CHANGE_MR_ID_BUTTON,
+  COLLAPSE_BUTTON,
+  COMMENT_BOX,
+  COMMENT_BUTTON,
+  FORM,
+  FORM_CONTAINER,
+  LOGIN,
+  LOGOUT,
+  MR_ID,
+  MR_ID_BUTTON,
+  NOTE,
+  NOTE_CONTAINER,
+  REMEMBER_ITEM,
+  REVIEW_CONTAINER,
+  TOKEN_BOX,
+  BLACK,
+  CLEAR,
+  MUTED,
+  RED,
+  WHITE,
+};

app/assets/javascripts/visual_review_toolbar/shared/storage_utils.js

+import { setUsingGracefulStorageFlag } from '../store/state';
+
+const TEST_KEY = 'gitlab-storage-test';
+
+const createStorageStub = () => {
+  const items = {};
+
+  return {
+    getItem(key) {
+      return items[key];
+    },
+    setItem(key, value) {
+      items[key] = value;
+    },
+    removeItem(key) {
+      delete items[key];
+    },
+  };
+};
+
+const hasStorageSupport = storage => {
+  // Support test taken from https://stackoverflow.com/a/11214467/1708147
+  try {
+    storage.setItem(TEST_KEY, TEST_KEY);
+    storage.removeItem(TEST_KEY);
+    setUsingGracefulStorageFlag(true);
+
+    return true;
+  } catch (err) {
+    setUsingGracefulStorageFlag(false);
+    return false;
+  }
+};
+
+const useGracefulStorage = storage =>
+  // If a browser does not support local storage, let's return a graceful implementation.
+  hasStorageSupport(storage) ? storage : createStorageStub();
+
+const localStorage = useGracefulStorage(window.localStorage);
+const sessionStorage = useGracefulStorage(window.sessionStorage);
+
+export { localStorage, sessionStorage };

app/assets/javascripts/visual_review_toolbar/store/events.js

 import {
+  addMr,
   authorizeUser,
+  changeSelectedMr,
   logoutUser,
   postComment,
+  saveComment,
   toggleForm,
+} from '../components';
+
+import {
+  CHANGE_MR_ID_BUTTON,
   COLLAPSE_BUTTON,
   COMMENT_BUTTON,
   LOGIN,
   LOGOUT,
-} from '../components';
+  MR_ID_BUTTON,
+} from '../shared';
 
 import { state } from './state';
+import debounce from './utils';
 
 const noop = () => {};
 
-const eventLookup = ({ target: { id } }) => {
+// State needs to be bound here to be acted on
+// because these are called by click events and
+// as such are called with only the `event` object
+const eventLookup = id => {
   switch (id) {
+    case CHANGE_MR_ID_BUTTON:
+      return () => {
+        saveComment();
+        changeSelectedMr(state);
+      };
     case COLLAPSE_BUTTON:
       return toggleForm;
     case COMMENT_BUTTON:
@@ -22,7 +39,12 @@ const eventLookup = ({ target: { id } }) => {
     case LOGIN:
       return authorizeUser.bind(null, state);
     case LOGOUT:
-      return logoutUser;
+      return () => {
+        saveComment();
+        logoutUser(state);
+      };
+    case MR_ID_BUTTON:
+      return addMr.bind(null, state);
     default:
       return noop;
   }
@@ -33,4 +55,19 @@ const updateWindowSize = wind => {
   state.innerHeight = wind.innerHeight;
 };
 
-export { eventLookup, updateWindowSize };
+const initializeGlobalListeners = () => {
+  window.addEventListener('resize', debounce(updateWindowSize.bind(null, window), 200));
+  window.addEventListener('beforeunload', event => {
+    if (state.usingGracefulStorage) {
+      // if there is no browser storage support, reloading will lose the comment; this way, the user will be warned
+      // we assign the return value because it is required by Chrome see: https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onbeforeunload#Example,
+      event.preventDefault();
+      /* eslint-disable-next-line no-param-reassign */
+      event.returnValue = '';
+    }
+
+    saveComment();
+  });
+};
+
+export { eventLookup, initializeGlobalListeners };

app/assets/javascripts/visual_review_toolbar/store/index.js

-import { eventLookup, updateWindowSize } from './events';
-import { getInitialView, initializeState } from './state';
-import debounce from './utils';
+import { eventLookup, initializeGlobalListeners } from './events';
+import { nextView, getInitialView, initializeState, setUsingGracefulStorageFlag } from './state';
 
-export { debounce, eventLookup, getInitialView, initializeState, updateWindowSize };
+export {
+  eventLookup,
+  getInitialView,
+  initializeGlobalListeners,
+  initializeState,
+  nextView,
+  setUsingGracefulStorageFlag,
+};

app/assets/javascripts/visual_review_toolbar/store/state.js

-import { comment, login, collapseButton } from '../components';
+import { comment, login, mrForm } from '../components';
+import { localStorage, COMMENT_BOX, LOGIN, MR_ID } from '../shared';
 
 const state = {
   browser: '',
-  href: '',
+  usingGracefulStorage: '',
   innerWidth: '',
   innerHeight: '',
   mergeRequestId: '',
@@ -23,11 +24,31 @@ const getBrowserId = sUsrAg => {
   return aKeys[nIdx];
 };
 
+const nextView = (appState, form = 'none') => {
+  const formsList = {
+    [COMMENT_BOX]: currentState => (currentState.token ? mrForm : login),
+    [LOGIN]: currentState => (currentState.mergeRequestId ? comment(currentState) : mrForm),
+    [MR_ID]: currentState => (currentState.token ? comment(currentState) : login),
+    none: currentState => {
+      if (!currentState.token) {
+        return login;
+      }
+
+      if (currentState.token && !currentState.mergeRequestId) {
+        return mrForm;
+      }
+
+      return comment(currentState);
+    },
+  };
+
+  return formsList[form](appState);
+};
+
 const initializeState = (wind, doc) => {
   const {
     innerWidth,
     innerHeight,
-    location: { href },
     navigator: { platform, userAgent },
   } = wind;
 
@@ -39,7 +60,6 @@ const initializeState = (wind, doc) => {
   // This mutates our default state object above. It's weird but it makes the linter happy.
   Object.assign(state, {
     browser,
-    href,
     innerWidth,
     innerHeight,
     mergeRequestId,
@@ -49,30 +69,27 @@ const initializeState = (wind, doc) => {
     projectPath,
     userAgent,
   });
-};
 
-function getInitialView({ localStorage }) {
-  const loginView = {
-    content: login,
-    toggleButton: collapseButton,
-  };
+  return state;
+};
 
-  const commentView = {
-    content: comment,
-    toggleButton: collapseButton,
-  };
+const getInitialView = () => {
+  const token = localStorage.getItem('token');
+  const mrId = localStorage.getItem('mergeRequestId');
 
-  try {
-    const token = localStorage.getItem('token');
+  if (token) {
+    state.token = token;
+  }
 
-    if (token) {
-      state.token = token;
-      return commentView;
-    }
-    return loginView;
-  } catch (err) {
-    return loginView;
+  if (mrId) {
+    state.mergeRequestId = mrId;
   }
-}
 
-export { initializeState, getInitialView, state };
+  return nextView(state);
+};
+
+const setUsingGracefulStorageFlag = flag => {
+  state.usingGracefulStorage = !flag;
+};
+
+export { initializeState, getInitialView, nextView, setUsingGracefulStorageFlag, state };

app/assets/javascripts/visual_review_toolbar/styles/toolbar.css

@@ -107,10 +107,14 @@
 }
 
 .gitlab-button-wrapper {
-  margin-top: 1rem;
+  margin-top: 0.5rem;
   display: flex;
   align-items: baseline;
-  justify-content: flex-end;
+  /*
+    this makes sure the hit enter to submit picks the correct button
+    on the comment view
+   */
+  flex-direction: row-reverse;
 }
 
 .gitlab-collapse {
@@ -155,6 +159,12 @@
   text-decoration: underline;
 }
 
+.gitlab-link-button {
+  border: none;
+  cursor: pointer;
+  padding: 0 .15rem;
+}
+
 .gitlab-message {
   padding: .25rem 0;
   margin: 0;
@@ -165,7 +175,7 @@
   font-size: .7rem;
   line-height: 1rem;
   color: #666;
-  margin-bottom: 0;
+  margin-bottom: .5rem;
 }
 
 .gitlab-input {

changelogs/unreleased/64190-add-mr-form.yml

+---
+title: Add MR form to Visual Review (EE) runtime configuration
+merge_request: 30481
+author:
+type: changed