Merge branch 'master' into issue_19734_2

34 files changed, 937 insertions, 563 deletions

diff --git a/app/assets/javascripts/dispatcher.js.es6 b/app/assets/javascripts/dispatcher.js.es6
index 5be35cf4b41..73691f40c74 100644
--- a/app/assets/javascripts/dispatcher.js.es6
+++ b/app/assets/javascripts/dispatcher.js.es6
@@ -101,9 +101,6 @@
           new ZenMode();
           new MergedButtons();
           break;
-        case "projects:merge_requests:conflicts":
-          window.mcui = new MergeConflictResolver()
-          break;
         case 'projects:merge_requests:index':
           shortcut_handler = new ShortcutsNavigation();
           Issuable.init();
diff --git a/app/assets/javascripts/merge_conflict_data_provider.js.es6 b/app/assets/javascripts/merge_conflict_data_provider.js.es6
deleted file mode 100644
index 13ee794ba38..00000000000
--- a/app/assets/javascripts/merge_conflict_data_provider.js.es6
+++ /dev/null
@@ -1,347 +0,0 @@
-const HEAD_HEADER_TEXT    = 'HEAD//our changes';
-const ORIGIN_HEADER_TEXT  = 'origin//their changes';
-const HEAD_BUTTON_TITLE   = 'Use ours';
-const ORIGIN_BUTTON_TITLE = 'Use theirs';
-
-
-class MergeConflictDataProvider {
-
-  getInitialData() {
-    // TODO: remove reliance on jQuery and DOM state introspection
-    const diffViewType = $.cookie('diff_view');
-    const fixedLayout = $('.content-wrapper .container-fluid').hasClass('container-limited');
-
-    return {
-      isLoading      : true,
-      hasError       : false,
-      isParallel     : diffViewType === 'parallel',
-      diffViewType   : diffViewType,
-      fixedLayout    : fixedLayout,
-      isSubmitting   : false,
-      conflictsData  : {},
-      resolutionData : {}
-    }
-  }
-
-
-  decorateData(vueInstance, data) {
-    this.vueInstance = vueInstance;
-
-    if (data.type === 'error') {
-      vueInstance.hasError = true;
-      data.errorMessage = data.message;
-    }
-    else {
-      data.shortCommitSha = data.commit_sha.slice(0, 7);
-      data.commitMessage  = data.commit_message;
-
-      this.setParallelLines(data);
-      this.setInlineLines(data);
-      this.updateResolutionsData(data);
-    }
-
-    vueInstance.conflictsData = data;
-    vueInstance.isSubmitting = false;
-
-    const conflictsText = this.getConflictsCount() > 1 ? 'conflicts' : 'conflict';
-    vueInstance.conflictsData.conflictsText = conflictsText;
-  }
-
-
-  updateResolutionsData(data) {
-    const vi = this.vueInstance;
-
-    data.files.forEach( (file) => {
-      file.sections.forEach( (section) => {
-        if (section.conflict) {
-          vi.$set(`resolutionData['${section.id}']`, false);
-        }
-      });
-    });
-  }
-
-
-  setParallelLines(data) {
-    data.files.forEach( (file) => {
-      file.filePath  = this.getFilePath(file);
-      file.iconClass = `fa-${file.blob_icon}`;
-      file.blobPath  = file.blob_path;
-      file.parallelLines = [];
-      const linesObj = { left: [], right: [] };
-
-      file.sections.forEach( (section) => {
-        const { conflict, lines, id } = section;
-
-        if (conflict) {
-          linesObj.left.push(this.getOriginHeaderLine(id));
-          linesObj.right.push(this.getHeadHeaderLine(id));
-        }
-
-        lines.forEach( (line) => {
-          const { type } = line;
-
-          if (conflict) {
-            if (type === 'old') {
-              linesObj.left.push(this.getLineForParallelView(line, id, 'conflict'));
-            }
-            else if (type === 'new') {
-              linesObj.right.push(this.getLineForParallelView(line, id, 'conflict', true));
-            }
-          }
-          else {
-            const lineType = type || 'context';
-
-            linesObj.left.push (this.getLineForParallelView(line, id, lineType));
-            linesObj.right.push(this.getLineForParallelView(line, id, lineType, true));
-          }
-        });
-
-        this.checkLineLengths(linesObj);
-      });
-
-      for (let i = 0, len = linesObj.left.length; i < len; i++) {
-        file.parallelLines.push([
-          linesObj.right[i],
-          linesObj.left[i]
-        ]);
-      }
-
-    });
-  }
-
-
-  checkLineLengths(linesObj) {
-    let { left, right } = linesObj;
-
-    if (left.length !== right.length) {
-      if (left.length > right.length) {
-        const diff = left.length - right.length;
-        for (let i = 0; i < diff; i++) {
-          right.push({ lineType: 'emptyLine', richText: '' });
-        }
-      }
-      else {
-        const diff = right.length - left.length;
-        for (let i = 0; i < diff; i++) {
-          left.push({ lineType: 'emptyLine', richText: '' });
-        }
-      }
-    }
-  }
-
-
-  setInlineLines(data) {
-    data.files.forEach( (file) => {
-      file.iconClass   = `fa-${file.blob_icon}`;
-      file.blobPath    = file.blob_path;
-      file.filePath    = this.getFilePath(file);
-      file.inlineLines = []
-
-      file.sections.forEach( (section) => {
-        let currentLineType = 'new';
-        const { conflict, lines, id } = section;
-
-        if (conflict) {
-          file.inlineLines.push(this.getHeadHeaderLine(id));
-        }
-
-        lines.forEach( (line) => {
-          const { type } = line;
-
-          if ((type === 'new' || type === 'old') && currentLineType !== type) {
-            currentLineType = type;
-            file.inlineLines.push({ lineType: 'emptyLine', richText: '' });
-          }
-
-          this.decorateLineForInlineView(line, id, conflict);
-          file.inlineLines.push(line);
-        })
-
-        if (conflict) {
-          file.inlineLines.push(this.getOriginHeaderLine(id));
-        }
-      });
-    });
-  }
-
-
-  handleSelected(sectionId, selection) {
-    const vi = this.vueInstance;
-
-    vi.resolutionData[sectionId] = selection;
-    vi.conflictsData.files.forEach( (file) => {
-      file.inlineLines.forEach( (line) => {
-        if (line.id === sectionId && (line.hasConflict || line.isHeader)) {
-          this.markLine(line, selection);
-        }
-      });
-
-      file.parallelLines.forEach( (lines) => {
-        const left         = lines[0];
-        const right        = lines[1];
-        const hasSameId    = right.id === sectionId || left.id === sectionId;
-        const isLeftMatch  = left.hasConflict || left.isHeader;
-        const isRightMatch = right.hasConflict || right.isHeader;
-
-        if (hasSameId && (isLeftMatch || isRightMatch)) {
-          this.markLine(left, selection);
-          this.markLine(right, selection);
-        }
-      })
-    });
-  }
-
-
-  updateViewType(newType) {
-    const vi = this.vueInstance;
-
-    if (newType === vi.diffViewType || !(newType === 'parallel' || newType === 'inline')) {
-      return;
-    }
-
-    vi.diffViewType = newType;
-    vi.isParallel   = newType === 'parallel';
-    $.cookie('diff_view', newType, {
-      path: (gon && gon.relative_url_root) || '/'
-    });
-    $('.content-wrapper .container-fluid')
-      .toggleClass('container-limited', !vi.isParallel && vi.fixedLayout);
-  }
-
-
-  markLine(line, selection) {
-    if (selection === 'head' && line.isHead) {
-      line.isSelected   = true;
-      line.isUnselected = false;
-    }
-    else if (selection === 'origin' && line.isOrigin) {
-      line.isSelected   = true;
-      line.isUnselected = false;
-    }
-    else {
-      line.isSelected   = false;
-      line.isUnselected = true;
-    }
-  }
-
-
-  getConflictsCount() {
-    return Object.keys(this.vueInstance.resolutionData).length;
-  }
-
-
-  getResolvedCount() {
-    let  count = 0;
-    const data = this.vueInstance.resolutionData;
-
-    for (const id in data) {
-      const resolution = data[id];
-      if (resolution) {
-        count++;
-      }
-    }
-
-    return count;
-  }
-
-
-  isReadyToCommit() {
-    const { conflictsData, isSubmitting } = this.vueInstance
-    const allResolved = this.getConflictsCount() === this.getResolvedCount();
-    const hasCommitMessage = $.trim(conflictsData.commitMessage).length;
-
-    return !isSubmitting && hasCommitMessage && allResolved;
-  }
-
-
-  getCommitButtonText() {
-    const initial = 'Commit conflict resolution';
-    const inProgress = 'Committing...';
-    const vue = this.vueInstance;
-
-    return vue ? vue.isSubmitting ? inProgress : initial : initial;
-  }
-
-
-  decorateLineForInlineView(line, id, conflict) {
-    const { type }    = line;
-    line.id           = id;
-    line.hasConflict  = conflict;
-    line.isHead       = type === 'new';
-    line.isOrigin     = type === 'old';
-    line.hasMatch     = type === 'match';
-    line.richText     = line.rich_text;
-    line.isSelected   = false;
-    line.isUnselected = false;
-  }
-
-  getLineForParallelView(line, id, lineType, isHead) {
-    const { old_line, new_line, rich_text } = line;
-    const hasConflict = lineType === 'conflict';
-
-    return {
-      id,
-      lineType,
-      hasConflict,
-      isHead       : hasConflict && isHead,
-      isOrigin     : hasConflict && !isHead,
-      hasMatch     : lineType === 'match',
-      lineNumber   : isHead ? new_line : old_line,
-      section      : isHead ? 'head' : 'origin',
-      richText     : rich_text,
-      isSelected   : false,
-      isUnselected : false
-    }
-  }
-
-
-  getHeadHeaderLine(id) {
-    return {
-      id          : id,
-      richText    : HEAD_HEADER_TEXT,
-      buttonTitle : HEAD_BUTTON_TITLE,
-      type        : 'new',
-      section     : 'head',
-      isHeader    : true,
-      isHead      : true,
-      isSelected  : false,
-      isUnselected: false
-    }
-  }
-
-
-  getOriginHeaderLine(id) {
-    return {
-      id          : id,
-      richText    : ORIGIN_HEADER_TEXT,
-      buttonTitle : ORIGIN_BUTTON_TITLE,
-      type        : 'old',
-      section     : 'origin',
-      isHeader    : true,
-      isOrigin    : true,
-      isSelected  : false,
-      isUnselected: false
-    }
-  }
-
-
-  handleFailedRequest(vueInstance, data) {
-    vueInstance.hasError = true;
-    vueInstance.conflictsData.errorMessage = 'Something went wrong!';
-  }
-
-
-  getCommitData() {
-    return {
-      commit_message: this.vueInstance.conflictsData.commitMessage,
-      sections: this.vueInstance.resolutionData
-    }
-  }
-
-
-  getFilePath(file) {
-    const { old_path, new_path } = file;
-    return old_path === new_path ? new_path : `${old_path} → ${new_path}`;
-  }
-
-}
diff --git a/app/assets/javascripts/merge_conflict_resolver.js.es6 b/app/assets/javascripts/merge_conflict_resolver.js.es6
deleted file mode 100644
index 7e756433bf5..00000000000
--- a/app/assets/javascripts/merge_conflict_resolver.js.es6
+++ /dev/null
@@ -1,82 +0,0 @@
-//= require vue
-
-class MergeConflictResolver {
-
-  constructor() {
-    this.dataProvider = new MergeConflictDataProvider()
-    this.initVue()
-  }
-
-
-  initVue() {
-    const that = this;
-    this.vue   = new Vue({
-      el       : '#conflicts',
-      name     : 'MergeConflictResolver',
-      data     : this.dataProvider.getInitialData(),
-      created  : this.fetchData(),
-      computed : this.setComputedProperties(),
-      methods  : {
-        handleSelected(sectionId, selection) {
-          that.dataProvider.handleSelected(sectionId, selection);
-        },
-        handleViewTypeChange(newType) {
-          that.dataProvider.updateViewType(newType);
-        },
-        commit() {
-          that.commit();
-        }
-      }
-    })
-  }
-
-
-  setComputedProperties() {
-    const dp = this.dataProvider;
-
-    return {
-      conflictsCount() { return dp.getConflictsCount() },
-      resolvedCount() { return dp.getResolvedCount() },
-      readyToCommit() { return dp.isReadyToCommit() },
-      commitButtonText() { return dp.getCommitButtonText() }
-    }
-  }
-
-
-  fetchData() {
-    const dp = this.dataProvider;
-
-    $.get($('#conflicts').data('conflictsPath'))
-      .done((data) => {
-        dp.decorateData(this.vue, data);
-      })
-      .error((data) => {
-        dp.handleFailedRequest(this.vue, data);
-      })
-      .always(() => {
-        this.vue.isLoading = false;
-
-        this.vue.$nextTick(() => {
-          $('#conflicts .js-syntax-highlight').syntaxHighlight();
-        });
-
-        $('.content-wrapper .container-fluid')
-          .toggleClass('container-limited', !this.vue.isParallel && this.vue.fixedLayout);
-      })
-  }
-
-
-  commit() {
-    this.vue.isSubmitting = true;
-
-    $.post($('#conflicts').data('resolveConflictsPath'), this.dataProvider.getCommitData())
-      .done((data) => {
-        window.location.href = data.redirect_to;
-      })
-      .error(() => {
-        this.vue.isSubmitting = false;
-        new Flash('Something went wrong!');
-      });
-  }
-
-}
diff --git a/app/assets/javascripts/merge_conflicts/components/diff_file_editor.js.es6 b/app/assets/javascripts/merge_conflicts/components/diff_file_editor.js.es6
new file mode 100644
index 00000000000..5012bdfe997
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/components/diff_file_editor.js.es6
@@ -0,0 +1,93 @@
+((global) => {
+
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  global.mergeConflicts.diffFileEditor = Vue.extend({
+    props: {
+      file: Object,
+      onCancelDiscardConfirmation: Function,
+      onAcceptDiscardConfirmation: Function
+    },
+    data() {
+      return {
+        saved: false,
+        loading: false,
+        fileLoaded: false,
+        originalContent: '',
+      }
+    },
+    computed: {
+      classObject() {
+        return {
+          'saved': this.saved,
+          'is-loading': this.loading
+        };
+      }
+    },
+    watch: {
+      ['file.showEditor'](val) {
+        this.resetEditorContent();
+
+        if (!val || this.fileLoaded || this.loading) {
+          return;
+        }
+
+        this.loadEditor();
+      }
+    },
+    ready() {
+      if (this.file.loadEditor) {
+        this.loadEditor();
+      }
+    },
+    methods: {
+      loadEditor() {
+        this.loading = true;
+
+        $.get(this.file.content_path)
+          .done((file) => {
+            let content = this.$el.querySelector('pre');
+            let fileContent = document.createTextNode(file.content);
+
+            content.textContent = fileContent.textContent;
+
+            this.originalContent = file.content;
+            this.fileLoaded = true;
+            this.editor = ace.edit(content);
+            this.editor.$blockScrolling = Infinity; // Turn off annoying warning
+            this.editor.getSession().setMode(`ace/mode/${file.blob_ace_mode}`);
+            this.editor.on('change', () => {
+              this.saveDiffResolution();
+            });
+            this.saveDiffResolution();
+          })
+          .fail(() => {
+            new Flash('Failed to load the file, please try again.');
+          })
+          .always(() => {
+            this.loading = false;
+          });
+      },
+      saveDiffResolution() {
+        this.saved = true;
+
+        // This probably be better placed in the data provider
+        this.file.content = this.editor.getValue();
+        this.file.resolveEditChanged = this.file.content !== this.originalContent;
+        this.file.promptDiscardConfirmation = false;
+      },
+      resetEditorContent() {
+        if (this.fileLoaded) {
+          this.editor.setValue(this.originalContent, -1);
+        }
+      },
+      cancelDiscardConfirmation(file) {
+        this.onCancelDiscardConfirmation(file);
+      },
+      acceptDiscardConfirmation(file) {
+        this.onAcceptDiscardConfirmation(file);
+      }
+    }
+  });
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/components/inline_conflict_lines.js.es6 b/app/assets/javascripts/merge_conflicts/components/inline_conflict_lines.js.es6
new file mode 100644
index 00000000000..b4be1c8988d
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/components/inline_conflict_lines.js.es6
@@ -0,0 +1,12 @@
+((global) => {
+
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  global.mergeConflicts.inlineConflictLines = Vue.extend({
+    props: {
+      file: Object
+    },
+    mixins: [global.mergeConflicts.utils, global.mergeConflicts.actions],
+  });
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/components/parallel_conflict_line.js.es6 b/app/assets/javascripts/merge_conflicts/components/parallel_conflict_line.js.es6
new file mode 100644
index 00000000000..8b0a8ab2073
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/components/parallel_conflict_line.js.es6
@@ -0,0 +1,14 @@
+((global) => {
+
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  global.mergeConflicts.parallelConflictLine = Vue.extend({
+    props: {
+      file: Object,
+      line: Object
+    },
+    mixins: [global.mergeConflicts.utils, global.mergeConflicts.actions],
+    template: '#parallel-conflict-line'
+  });
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/components/parallel_conflict_lines.js.es6 b/app/assets/javascripts/merge_conflicts/components/parallel_conflict_lines.js.es6
new file mode 100644
index 00000000000..eb4cc6a9dac
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/components/parallel_conflict_lines.js.es6
@@ -0,0 +1,15 @@
+((global) => {
+
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  global.mergeConflicts.parallelConflictLines = Vue.extend({
+    props: {
+      file: Object
+    },
+    mixins: [global.mergeConflicts.utils],
+    components: {
+      'parallel-conflict-line': gl.mergeConflicts.parallelConflictLine
+    }
+  });
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/merge_conflict_service.js.es6 b/app/assets/javascripts/merge_conflicts/merge_conflict_service.js.es6
new file mode 100644
index 00000000000..da2fb8b1323
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/merge_conflict_service.js.es6
@@ -0,0 +1,30 @@
+((global) => {
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  class mergeConflictsService {
+    constructor(options) {
+      this.conflictsPath = options.conflictsPath;
+      this.resolveConflictsPath = options.resolveConflictsPath;
+    }
+
+    fetchConflictsData() {
+      return $.ajax({
+        dataType: 'json',
+        url: this.conflictsPath
+      });
+    }
+
+    submitResolveConflicts(data) {
+      return $.ajax({
+        url: this.resolveConflictsPath,
+        data: JSON.stringify(data),
+        contentType: 'application/json',
+        dataType: 'json',
+        method: 'POST'
+      });
+    }
+  };
+
+  global.mergeConflicts.mergeConflictsService = mergeConflictsService;
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/merge_conflict_store.js.es6 b/app/assets/javascripts/merge_conflicts/merge_conflict_store.js.es6
new file mode 100644
index 00000000000..5c5c65f29d4
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/merge_conflict_store.js.es6
@@ -0,0 +1,437 @@
+((global) => {
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  const diffViewType = $.cookie('diff_view');
+  const HEAD_HEADER_TEXT = 'HEAD//our changes';
+  const ORIGIN_HEADER_TEXT = 'origin//their changes';
+  const HEAD_BUTTON_TITLE = 'Use ours';
+  const ORIGIN_BUTTON_TITLE = 'Use theirs';
+  const INTERACTIVE_RESOLVE_MODE = 'interactive';
+  const EDIT_RESOLVE_MODE = 'edit';
+  const DEFAULT_RESOLVE_MODE = INTERACTIVE_RESOLVE_MODE;
+  const VIEW_TYPES = {
+    INLINE: 'inline',
+    PARALLEL: 'parallel'
+  };
+  const CONFLICT_TYPES = {
+    TEXT: 'text',
+    TEXT_EDITOR: 'text-editor'
+  };
+
+  global.mergeConflicts.mergeConflictsStore = {
+    state: {
+      isLoading: true,
+      hasError: false,
+      isSubmitting: false,
+      isParallel: diffViewType === VIEW_TYPES.PARALLEL,
+      diffViewType: diffViewType,
+      conflictsData: {}
+    },
+
+    setConflictsData(data) {
+      this.decorateFiles(data.files);
+
+      this.state.conflictsData = {
+        files: data.files,
+        commitMessage: data.commit_message,
+        sourceBranch: data.source_branch,
+        targetBranch: data.target_branch,
+        commitMessage: data.commit_message,
+        shortCommitSha: data.commit_sha.slice(0, 7),
+      };
+    },
+
+    decorateFiles(files) {
+      files.forEach((file) => {
+        file.content = '';
+        file.resolutionData = {};
+        file.promptDiscardConfirmation = false;
+        file.resolveMode = DEFAULT_RESOLVE_MODE;
+        file.filePath = this.getFilePath(file);
+        file.iconClass = `fa-${file.blob_icon}`;
+        file.blobPath = file.blob_path;
+
+        if (file.type === CONFLICT_TYPES.TEXT) {
+          file.showEditor = false;
+          file.loadEditor = false;
+
+          this.setInlineLine(file);
+          this.setParallelLine(file);
+        } else if (file.type === CONFLICT_TYPES.TEXT_EDITOR) {
+          file.showEditor = true;
+          file.loadEditor = true;
+        }
+      });
+    },
+
+    setInlineLine(file) {
+      file.inlineLines = [];
+
+      file.sections.forEach((section) => {
+        let currentLineType = 'new';
+        const { conflict, lines, id } = section;
+
+        if (conflict) {
+          file.inlineLines.push(this.getHeadHeaderLine(id));
+        }
+
+        lines.forEach((line) => {
+          const { type } = line;
+
+          if ((type === 'new' || type === 'old') && currentLineType !== type) {
+            currentLineType = type;
+            file.inlineLines.push({ lineType: 'emptyLine', richText: '' });
+          }
+
+          this.decorateLineForInlineView(line, id, conflict);
+          file.inlineLines.push(line);
+        })
+
+        if (conflict) {
+          file.inlineLines.push(this.getOriginHeaderLine(id));
+        }
+      });
+    },
+
+    setParallelLine(file) {
+      file.parallelLines = [];
+      const linesObj = { left: [], right: [] };
+
+      file.sections.forEach((section) => {
+        const { conflict, lines, id } = section;
+
+        if (conflict) {
+          linesObj.left.push(this.getOriginHeaderLine(id));
+          linesObj.right.push(this.getHeadHeaderLine(id));
+        }
+
+        lines.forEach((line) => {
+          const { type } = line;
+
+          if (conflict) {
+            if (type === 'old') {
+              linesObj.left.push(this.getLineForParallelView(line, id, 'conflict'));
+            } else if (type === 'new') {
+              linesObj.right.push(this.getLineForParallelView(line, id, 'conflict', true));
+            }
+          } else {
+            const lineType = type || 'context';
+
+            linesObj.left.push (this.getLineForParallelView(line, id, lineType));
+            linesObj.right.push(this.getLineForParallelView(line, id, lineType, true));
+          }
+        });
+
+        this.checkLineLengths(linesObj);
+      });
+
+      for (let i = 0, len = linesObj.left.length; i < len; i++) {
+        file.parallelLines.push([
+          linesObj.right[i],
+          linesObj.left[i]
+        ]);
+      }
+    },
+
+    setLoadingState(state) {
+      this.state.isLoading = state;
+    },
+
+    setErrorState(state) {
+      this.state.hasError = state;
+    },
+
+    setFailedRequest(message) {
+      this.state.hasError = true;
+      this.state.conflictsData.errorMessage = message;
+    },
+
+    getConflictsCount() {
+      if (!this.state.conflictsData.files.length) {
+        return 0;
+      }
+
+      const files = this.state.conflictsData.files;
+      let count = 0;
+
+      files.forEach((file) => {
+        if (file.type === CONFLICT_TYPES.TEXT) {
+          file.sections.forEach((section) => {
+            if (section.conflict) {
+              count++;
+            }
+          });
+        } else {
+          count++;
+        }
+      });
+
+      return count;
+    },
+
+    getConflictsCountText() {
+      const count = this.getConflictsCount();
+      const text = count ? 'conflicts' : 'conflict';
+
+      return `${count} ${text}`;
+    },
+
+    setViewType(viewType) {
+      this.state.diffView = viewType;
+      this.state.isParallel = viewType === VIEW_TYPES.PARALLEL;
+
+      $.cookie('diff_view', viewType, {
+        path: gon.relative_url_root || '/'
+      });
+    },
+
+    getHeadHeaderLine(id) {
+      return {
+        id: id,
+        richText: HEAD_HEADER_TEXT,
+        buttonTitle: HEAD_BUTTON_TITLE,
+        type: 'new',
+        section: 'head',
+        isHeader: true,
+        isHead: true,
+        isSelected: false,
+        isUnselected: false
+      };
+    },
+
+    decorateLineForInlineView(line, id, conflict) {
+      const { type } = line;
+      line.id = id;
+      line.hasConflict = conflict;
+      line.isHead = type === 'new';
+      line.isOrigin = type === 'old';
+      line.hasMatch = type === 'match';
+      line.richText = line.rich_text;
+      line.isSelected = false;
+      line.isUnselected = false;
+    },
+
+    getLineForParallelView(line, id, lineType, isHead) {
+      const { old_line, new_line, rich_text } = line;
+      const hasConflict = lineType === 'conflict';
+
+      return {
+        id,
+        lineType,
+        hasConflict,
+        isHead: hasConflict && isHead,
+        isOrigin: hasConflict && !isHead,
+        hasMatch: lineType === 'match',
+        lineNumber: isHead ? new_line : old_line,
+        section: isHead ? 'head' : 'origin',
+        richText: rich_text,
+        isSelected: false,
+        isUnselected: false
+      };
+    },
+
+    getOriginHeaderLine(id) {
+      return {
+        id: id,
+        richText: ORIGIN_HEADER_TEXT,
+        buttonTitle: ORIGIN_BUTTON_TITLE,
+        type: 'old',
+        section: 'origin',
+        isHeader: true,
+        isOrigin: true,
+        isSelected: false,
+        isUnselected: false
+      };
+    },
+
+    getFilePath(file) {
+      const { old_path, new_path } = file;
+      return old_path === new_path ? new_path : `${old_path} → ${new_path}`;
+    },
+
+    checkLineLengths(linesObj) {
+      let { left, right } = linesObj;
+
+      if (left.length !== right.length) {
+        if (left.length > right.length) {
+          const diff = left.length - right.length;
+          for (let i = 0; i < diff; i++) {
+            right.push({ lineType: 'emptyLine', richText: '' });
+          }
+        } else {
+          const diff = right.length - left.length;
+          for (let i = 0; i < diff; i++) {
+            left.push({ lineType: 'emptyLine', richText: '' });
+          }
+        }
+      }
+    },
+
+    setPromptConfirmationState(file, state) {
+      file.promptDiscardConfirmation = state;
+    },
+
+    setFileResolveMode(file, mode) {
+      if (mode === INTERACTIVE_RESOLVE_MODE) {
+        file.showEditor = false;
+      } else if (mode === EDIT_RESOLVE_MODE) {
+        // Restore Interactive mode when switching to Edit mode
+        file.showEditor = true;
+        file.loadEditor = true;
+        file.resolutionData = {};
+
+        this.restoreFileLinesState(file);
+      }
+
+      file.resolveMode = mode;
+    },
+
+    restoreFileLinesState(file) {
+      file.inlineLines.forEach((line) => {
+        if (line.hasConflict || line.isHeader) {
+          line.isSelected = false;
+          line.isUnselected = false;
+        }
+      });
+
+      file.parallelLines.forEach((lines) => {
+        const left = lines[0];
+        const right = lines[1];
+        const isLeftMatch = left.hasConflict || left.isHeader;
+        const isRightMatch = right.hasConflict || right.isHeader;
+
+        if (isLeftMatch || isRightMatch) {
+          left.isSelected = false;
+          left.isUnselected = false;
+          right.isSelected = false;
+          right.isUnselected = false;
+        }
+      });
+    },
+
+    isReadyToCommit() {
+      const files = this.state.conflictsData.files;
+      const hasCommitMessage = $.trim(this.state.conflictsData.commitMessage).length;
+      let unresolved = 0;
+
+      for (let i = 0, l = files.length; i < l; i++) {
+        let file = files[i];
+
+        if (file.resolveMode === INTERACTIVE_RESOLVE_MODE) {
+          let numberConflicts = 0;
+          let resolvedConflicts = Object.keys(file.resolutionData).length
+
+          // We only check for conflicts type 'text'
+          // since conflicts `text_editor` can´t be resolved in interactive mode
+          if (file.type === CONFLICT_TYPES.TEXT) {
+            for (let j = 0, k = file.sections.length; j < k; j++) {
+              if (file.sections[j].conflict) {
+                numberConflicts++;
+              }
+            }
+
+            if (resolvedConflicts !== numberConflicts) {
+              unresolved++;
+            }
+          }
+        } else if (file.resolveMode === EDIT_RESOLVE_MODE) {
+
+          // Unlikely to happen since switching to Edit mode saves content automatically.
+          // Checking anyway in case the save strategy changes in the future
+          if (!file.content) {
+            unresolved++;
+            continue;
+          }
+        }
+      }
+
+      return !this.state.isSubmitting && hasCommitMessage && !unresolved;
+    },
+
+    getCommitButtonText() {
+      const initial = 'Commit conflict resolution';
+      const inProgress = 'Committing...';
+
+      return this.state ? this.state.isSubmitting ? inProgress : initial : initial;
+    },
+
+    getCommitData() {
+      let commitData = {};
+
+      commitData = {
+        commit_message: this.state.conflictsData.commitMessage,
+        files: []
+      };
+
+      this.state.conflictsData.files.forEach((file) => {
+        let addFile;
+
+        addFile = {
+          old_path: file.old_path,
+          new_path: file.new_path
+        };
+
+        if (file.type === CONFLICT_TYPES.TEXT) {
+
+          // Submit only one data for type of editing
+          if (file.resolveMode === INTERACTIVE_RESOLVE_MODE) {
+            addFile.sections = file.resolutionData;
+          } else if (file.resolveMode === EDIT_RESOLVE_MODE) {
+            addFile.content = file.content;
+          }
+        } else if (file.type === CONFLICT_TYPES.TEXT_EDITOR) {
+          addFile.content = file.content;
+        }
+
+        commitData.files.push(addFile);
+      });
+
+      return commitData;
+    },
+
+    handleSelected(file, sectionId, selection) {
+      Vue.set(file.resolutionData, sectionId, selection);
+
+      file.inlineLines.forEach((line) => {
+        if (line.id === sectionId && (line.hasConflict || line.isHeader)) {
+          this.markLine(line, selection);
+        }
+      });
+
+      file.parallelLines.forEach((lines) => {
+        const left = lines[0];
+        const right = lines[1];
+        const hasSameId = right.id === sectionId || left.id === sectionId;
+        const isLeftMatch = left.hasConflict || left.isHeader;
+        const isRightMatch = right.hasConflict || right.isHeader;
+
+        if (hasSameId && (isLeftMatch || isRightMatch)) {
+          this.markLine(left, selection);
+          this.markLine(right, selection);
+        }
+      });
+    },
+
+    markLine(line, selection) {
+      if (selection === 'head' && line.isHead) {
+        line.isSelected = true;
+        line.isUnselected = false;
+      } else if (selection === 'origin' && line.isOrigin) {
+        line.isSelected = true;
+        line.isUnselected = false;
+      } else {
+        line.isSelected = false;
+        line.isUnselected = true;
+      }
+    },
+
+    setSubmitState(state) {
+      this.state.isSubmitting = state;
+    },
+
+    fileTextTypePresent() {
+      return this.state.conflictsData.files.some(f => f.type === CONFLICT_TYPES.TEXT);
+    }
+  };
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js.es6 b/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js.es6
new file mode 100644
index 00000000000..7fd3749b3e2
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/merge_conflicts_bundle.js.es6
@@ -0,0 +1,89 @@
+//= require vue
+//= require ./merge_conflict_store
+//= require ./merge_conflict_service
+//= require ./mixins/line_conflict_utils
+//= require ./mixins/line_conflict_actions
+//= require ./components/diff_file_editor
+//= require ./components/inline_conflict_lines
+//= require ./components/parallel_conflict_line
+//= require ./components/parallel_conflict_lines
+
+$(() => {
+  const INTERACTIVE_RESOLVE_MODE = 'interactive';
+  const conflictsEl = document.querySelector('#conflicts');
+  const mergeConflictsStore = gl.mergeConflicts.mergeConflictsStore;
+  const mergeConflictsService = new gl.mergeConflicts.mergeConflictsService({
+    conflictsPath: conflictsEl.dataset.conflictsPath,
+    resolveConflictsPath: conflictsEl.dataset.resolveConflictsPath
+  });
+
+  gl.MergeConflictsResolverApp = new Vue({
+    el: '#conflicts',
+    data: mergeConflictsStore.state,
+    components: {
+      'diff-file-editor': gl.mergeConflicts.diffFileEditor,
+      'inline-conflict-lines': gl.mergeConflicts.inlineConflictLines,
+      'parallel-conflict-lines': gl.mergeConflicts.parallelConflictLines
+    },
+    computed: {
+      conflictsCountText() { return mergeConflictsStore.getConflictsCountText() },
+      readyToCommit() { return mergeConflictsStore.isReadyToCommit() },
+      commitButtonText() { return mergeConflictsStore.getCommitButtonText() },
+      showDiffViewTypeSwitcher() { return mergeConflictsStore.fileTextTypePresent() }
+    },
+    created() {
+      mergeConflictsService
+        .fetchConflictsData()
+        .done((data) => {
+          if (data.type === 'error') {
+            mergeConflictsStore.setFailedRequest(data.message);
+          } else {
+            mergeConflictsStore.setConflictsData(data);
+          }
+        })
+        .error(() => {
+          mergeConflictsStore.setFailedRequest();
+        })
+        .always(() => {
+          mergeConflictsStore.setLoadingState(false);
+
+          this.$nextTick(() => {
+            $(conflictsEl.querySelectorAll('.js-syntax-highlight')).syntaxHighlight();
+          });
+        });
+    },
+    methods: {
+      handleViewTypeChange(viewType) {
+        mergeConflictsStore.setViewType(viewType);
+      },
+      onClickResolveModeButton(file, mode) {
+        if (mode === INTERACTIVE_RESOLVE_MODE && file.resolveEditChanged) {
+          mergeConflictsStore.setPromptConfirmationState(file, true);
+          return;
+        }
+
+        mergeConflictsStore.setFileResolveMode(file, mode);
+      },
+      acceptDiscardConfirmation(file) {
+        mergeConflictsStore.setPromptConfirmationState(file, false);
+        mergeConflictsStore.setFileResolveMode(file, INTERACTIVE_RESOLVE_MODE);
+      },
+      cancelDiscardConfirmation(file) {
+        mergeConflictsStore.setPromptConfirmationState(file, false);
+      },
+      commit() {
+        mergeConflictsStore.setSubmitState(true);
+
+        mergeConflictsService
+          .submitResolveConflicts(mergeConflictsStore.getCommitData())
+          .done((data) => {
+            window.location.href = data.redirect_to;
+          })
+          .error(() => {
+            mergeConflictsStore.setSubmitState(false);
+            new Flash('Failed to save merge conflicts resolutions. Please try again!');
+          });
+      }
+    }
+  })
+});
diff --git a/app/assets/javascripts/merge_conflicts/mixins/line_conflict_actions.js.es6 b/app/assets/javascripts/merge_conflicts/mixins/line_conflict_actions.js.es6
new file mode 100644
index 00000000000..114a2c5b305
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/mixins/line_conflict_actions.js.es6
@@ -0,0 +1,12 @@
+((global) => {
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  global.mergeConflicts.actions = {
+    methods: {
+      handleSelected(file, sectionId, selection) {
+        gl.mergeConflicts.mergeConflictsStore.handleSelected(file, sectionId, selection);
+      }
+    }
+  };
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/merge_conflicts/mixins/line_conflict_utils.js.es6 b/app/assets/javascripts/merge_conflicts/mixins/line_conflict_utils.js.es6
new file mode 100644
index 00000000000..b846a90ab2a
--- /dev/null
+++ b/app/assets/javascripts/merge_conflicts/mixins/line_conflict_utils.js.es6
@@ -0,0 +1,18 @@
+((global) => {
+  global.mergeConflicts = global.mergeConflicts || {};
+
+  global.mergeConflicts.utils = {
+    methods: {
+      lineCssClass(line) {
+        return {
+          'head': line.isHead,
+          'origin': line.isOrigin,
+          'match': line.hasMatch,
+          'selected': line.isSelected,
+          'unselected': line.isUnselected
+        };
+      }
+    }
+  };
+
+})(window.gl || (window.gl = {}));
diff --git a/app/assets/javascripts/username_validator.js.es6 b/app/assets/javascripts/username_validator.js.es6
index 2517f778365..bf4b2e320cd 100644
--- a/app/assets/javascripts/username_validator.js.es6
+++ b/app/assets/javascripts/username_validator.js.es6
@@ -76,7 +76,7 @@
         this.renderState();
         return $.ajax({
           type: 'GET',
-          url: `/u/${username}/exists`,
+          url: `/users/${username}/exists`,
           dataType: 'json',
           success: (res) => this.setAvailabilityState(res.exists)
         });
diff --git a/app/assets/stylesheets/framework/typography.scss b/app/assets/stylesheets/framework/typography.scss
index 287653beac5..55de9053be5 100644
--- a/app/assets/stylesheets/framework/typography.scss
+++ b/app/assets/stylesheets/framework/typography.scss
@@ -45,40 +45,38 @@
   }
 
   h1 {
-    font-size: 2em;
+    font-size: 1.75em;
     font-weight: 600;
-    margin: 1em 0 10px;
+    margin: 16px 0 10px;
     padding: 0 0 0.3em;
-    border-bottom: 1px solid $btn-default-border;
+    border-bottom: 1px solid $white-dark;
     color: $gl-gray-dark;
   }
 
   h2 {
-    font-size: 1.6em;
+    font-size: 1.5em;
     font-weight: 600;
-    margin: 1em 0 10px;
-    padding-bottom: 0.3em;
-    border-bottom: 1px solid $btn-default-border;
+    margin: 16px 0 10px;
     color: $gl-gray-dark;
   }
 
   h3 {
-    margin: 1em 0 10px;
-    font-size: 1.4em;
+    margin: 16px 0 10px;
+    font-size: 1.3em;
   }
 
   h4 {
-    margin: 1em 0 10px;
-    font-size: 1.25em;
+    margin: 16px 0 10px;
+    font-size: 1.2em;
   }
 
   h5 {
-    margin: 1em 0 10px;
+    margin: 16px 0 10px;
     font-size: 1em;
   }
 
   h6 {
-    margin: 1em 0 10px;
+    margin: 16px 0 10px;
     font-size: 0.95em;
   }
 
@@ -87,12 +85,12 @@
     font-size: inherit;
     padding: 8px 21px;
     margin: 12px 0;
-    border-left: 3px solid #e7e9ed;
+    border-left: 3px solid $white-dark;
   }
 
   blockquote:dir(rtl) {
     border-left: 0;
-    border-right: 3px solid #e7e9ed;
+    border-right: 3px solid $white-dark;
   }
 
   blockquote p {
diff --git a/app/assets/stylesheets/framework/variables.scss b/app/assets/stylesheets/framework/variables.scss
index 4c34ed3ebf7..7690d65de8e 100644
--- a/app/assets/stylesheets/framework/variables.scss
+++ b/app/assets/stylesheets/framework/variables.scss
@@ -56,6 +56,7 @@ $border-gray-light: #dcdcdc;
 $border-gray-normal: #d7d7d7;
 $border-gray-dark: #c6cacf;
 
+$border-green-extra-light: #9adb84;
 $border-green-light: #2faa60;
 $border-green-normal: #2ca05b;
 $border-green-dark: #279654;
diff --git a/app/assets/stylesheets/pages/detail_page.scss b/app/assets/stylesheets/pages/detail_page.scss
index 4d9c73c6840..2357671c2ae 100644
--- a/app/assets/stylesheets/pages/detail_page.scss
+++ b/app/assets/stylesheets/pages/detail_page.scss
@@ -20,9 +20,11 @@
 
 .detail-page-description {
   .title {
-    margin: 0;
-    font-size: 23px;
+    margin: 0 0 16px;
+    font-size: 2em;
     color: $gl-gray-dark;
+    padding: 0 0 0.3em;
+    border-bottom: 1px solid $white-dark;
   }
 
   .description {
diff --git a/app/assets/stylesheets/pages/merge_conflicts.scss b/app/assets/stylesheets/pages/merge_conflicts.scss
index 49013d7cac9..eed2b0ab7cc 100644
--- a/app/assets/stylesheets/pages/merge_conflicts.scss
+++ b/app/assets/stylesheets/pages/merge_conflicts.scss
@@ -237,4 +237,51 @@ $colors: (
   .btn-success .fa-spinner {
     color: #fff;
   }
+
+  .editor-wrap {
+    &.is-loading {
+      .editor {
+        display: none;
+      }
+
+      .loading {
+        display: block;
+      }
+    }
+
+    &.saved {
+      .editor {
+        border-top: solid 2px $border-green-extra-light;
+      }
+    }
+    
+    .editor {
+      pre {
+        height: 350px;
+        border: none;
+        border-radius: 0;
+        margin-bottom: 0;
+      }
+    }
+
+    .loading {
+      display: none;
+    }
+  }
+
+  .discard-changes-alert {
+    background-color: $background-color;
+    text-align: right;
+    padding: $gl-padding-top $gl-padding;
+    color: $gl-text-color;
+
+    .discard-actions {
+      display: inline-block;
+      margin-left: 10px;
+    }
+  }
+
+  .resolve-conflicts-form {
+    padding-top: $gl-padding;
+  }
 }
diff --git a/app/assets/stylesheets/pages/merge_requests.scss b/app/assets/stylesheets/pages/merge_requests.scss
index afc4e517fde..101472278e2 100644
--- a/app/assets/stylesheets/pages/merge_requests.scss
+++ b/app/assets/stylesheets/pages/merge_requests.scss
@@ -429,13 +429,6 @@
   }
 }
 
-.merge-request-details {
-
-  .title {
-    margin-bottom: 20px;
-  }
-}
-
 .merge-request-tabs {
   background-color: #fff;
 
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 705824502eb..37600ed875c 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -118,7 +118,12 @@ class ApplicationController < ActionController::Base
   end
 
   def render_404
-    render file: Rails.root.join("public", "404"), layout: false, status: "404"
+    respond_to do |format|
+      format.html do
+        render file: Rails.root.join("public", "404"), layout: false, status: "404"
+      end
+      format.any { head :not_found }
+    end
   end
 
   def no_cache_headers
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 9207c954335..a39b47b6d95 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -9,15 +9,15 @@ class Projects::MergeRequestsController < Projects::ApplicationController
 
   before_action :module_enabled
   before_action :merge_request, only: [
-    :edit, :update, :show, :diffs, :commits, :conflicts, :builds, :pipelines, :merge, :merge_check,
+    :edit, :update, :show, :diffs, :commits, :conflicts, :conflict_for_path, :builds, :pipelines, :merge, :merge_check,
     :ci_status, :ci_environments_status, :toggle_subscription, :cancel_merge_when_build_succeeds, :remove_wip, :resolve_conflicts, :assign_related_issues
   ]
   before_action :validates_merge_request, only: [:show, :diffs, :commits, :builds, :pipelines]
-  before_action :define_show_vars, only: [:show, :diffs, :commits, :conflicts, :builds, :pipelines]
+  before_action :define_show_vars, only: [:show, :diffs, :commits, :conflicts, :conflict_for_path, :builds, :pipelines]
   before_action :define_widget_vars, only: [:merge, :cancel_merge_when_build_succeeds, :merge_check]
   before_action :define_commit_vars, only: [:diffs]
   before_action :define_diff_comment_vars, only: [:diffs]
-  before_action :ensure_ref_fetched, only: [:show, :diffs, :commits, :builds, :conflicts, :pipelines]
+  before_action :ensure_ref_fetched, only: [:show, :diffs, :commits, :builds, :conflicts, :conflict_for_path, :pipelines]
   before_action :close_merge_request_without_source_project, only: [:show, :diffs, :commits, :builds, :pipelines]
   before_action :apply_diff_view_cookie!, only: [:new_diffs]
   before_action :build_merge_request, only: [:new, :new_diffs]
@@ -33,7 +33,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
 
   before_action :authenticate_user!, only: [:assign_related_issues]
 
-  before_action :authorize_can_resolve_conflicts!, only: [:conflicts, :resolve_conflicts]
+  before_action :authorize_can_resolve_conflicts!, only: [:conflicts, :conflict_for_path, :resolve_conflicts]
 
   def index
     @merge_requests = merge_requests_collection
@@ -170,6 +170,16 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     end
   end
 
+  def conflict_for_path
+    return render_404 unless @merge_request.conflicts_can_be_resolved_in_ui?
+
+    file = @merge_request.conflicts.file_for_path(params[:old_path], params[:new_path])
+
+    return render_404 unless file
+
+    render json: file, full_content: true
+  end
+
   def resolve_conflicts
     return render_404 unless @merge_request.conflicts_can_be_resolved_in_ui?
 
@@ -184,7 +194,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
       flash[:notice] = 'All merge conflicts were resolved. The merge request can now be merged.'
 
       render json: { redirect_to: namespace_project_merge_request_url(@project.namespace, @project, @merge_request, resolved_conflicts: true) }
-    rescue Gitlab::Conflict::File::MissingResolution => e
+    rescue Gitlab::Conflict::ResolutionError => e
       render status: :bad_request, json: { message: e.message }
     end
   end
diff --git a/app/helpers/award_emoji_helper.rb b/app/helpers/award_emoji_helper.rb
index aa134cea31c..493f14f6f9d 100644
--- a/app/helpers/award_emoji_helper.rb
+++ b/app/helpers/award_emoji_helper.rb
@@ -1,9 +1,12 @@
 module AwardEmojiHelper
   def toggle_award_url(awardable)
-    if @project
-      url_for([:toggle_award_emoji, @project.namespace.becomes(Namespace), @project, awardable])
+    return url_for([:toggle_award_emoji, awardable]) unless @project
+
+    if awardable.is_a?(Note)
+      # We render a list of notes very frequently and calling the specific method is a lot faster than the generic one (6.5x)
+      toggle_award_emoji_namespace_project_note_url(namespace_id: @project.namespace_id, project_id: @project.id, id: awardable.id)
     else
-      url_for([:toggle_award_emoji, awardable])
+      url_for([:toggle_award_emoji, @project.namespace.becomes(Namespace), @project, awardable])
     end
   end
 end
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 5ccfe11a2a2..8c6905a442d 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -871,7 +871,7 @@ class MergeRequest < ActiveRecord::Base
       # files.
       conflicts.files.each(&:lines)
       @conflicts_can_be_resolved_in_ui = conflicts.files.length > 0
-    rescue Rugged::OdbError, Gitlab::Conflict::Parser::ParserError, Gitlab::Conflict::FileCollection::ConflictSideMissing
+    rescue Rugged::OdbError, Gitlab::Conflict::Parser::UnresolvableError, Gitlab::Conflict::FileCollection::ConflictSideMissing
       @conflicts_can_be_resolved_in_ui = false
     end
   end
diff --git a/app/services/merge_requests/resolve_service.rb b/app/services/merge_requests/resolve_service.rb
index 19caa038c44..d22a1d3e0ad 100644
--- a/app/services/merge_requests/resolve_service.rb
+++ b/app/services/merge_requests/resolve_service.rb
@@ -1,5 +1,8 @@
 module MergeRequests
   class ResolveService < MergeRequests::BaseService
+    class MissingFiles < Gitlab::Conflict::ResolutionError
+    end
+
     attr_accessor :conflicts, :rugged, :merge_index, :merge_request
 
     def execute(merge_request)
@@ -10,8 +13,16 @@ module MergeRequests
 
       fetch_their_commit!
 
-      conflicts.files.each do |file|
-        write_resolved_file_to_index(file, params[:sections])
+      params[:files].each do |file_params|
+        conflict_file = merge_request.conflicts.file_for_path(file_params[:old_path], file_params[:new_path])
+
+        write_resolved_file_to_index(conflict_file, file_params)
+      end
+
+      unless merge_index.conflicts.empty?
+        missing_files = merge_index.conflicts.map { |file| file[:ours][:path] }
+
+        raise MissingFiles, "Missing resolutions for the following files: #{missing_files.join(', ')}"
       end
 
       commit_params = {
@@ -23,8 +34,13 @@ module MergeRequests
       project.repository.resolve_conflicts(current_user, merge_request.source_branch, commit_params)
     end
 
-    def write_resolved_file_to_index(file, resolutions)
-      new_file = file.resolve_lines(resolutions).map(&:text).join("\n")
+    def write_resolved_file_to_index(file, params)
+      new_file = if params[:sections]
+                   file.resolve_lines(params[:sections]).map(&:text).join("\n")
+                 elsif params[:content]
+                   file.resolve_content(params[:content])
+                 end
+
       our_path = file.our_path
 
       merge_index.add(path: our_path, oid: rugged.write(new_file, :blob), mode: file.our_mode)
diff --git a/app/views/projects/merge_requests/conflicts.html.haml b/app/views/projects/merge_requests/conflicts.html.haml
index a524936f73c..d9f74d2cbfb 100644
--- a/app/views/projects/merge_requests/conflicts.html.haml
+++ b/app/views/projects/merge_requests/conflicts.html.haml
@@ -1,11 +1,7 @@
-- class_bindings = "{ |
-    'head': line.isHead, |
-    'origin': line.isOrigin, |
-    'match': line.hasMatch, |
-    'selected': line.isSelected, |
-    'unselected': line.isUnselected }"
-
 - page_title "Merge Conflicts", "#{@merge_request.title} (#{@merge_request.to_reference}", "Merge Requests"
+- content_for :page_specific_javascripts do
+  = page_specific_javascript_tag('merge_conflicts/merge_conflicts_bundle.js')
+  = page_specific_javascript_tag('lib/ace.js')
 = render "projects/merge_requests/show/mr_title"
 
 .merge-request-details.issuable-details
@@ -24,6 +20,21 @@
   = render partial: "projects/merge_requests/conflicts/commit_stats"
 
   .files-wrapper{"v-if" => "!isLoading && !hasError"}
-    = render partial: "projects/merge_requests/conflicts/parallel_view", locals: { class_bindings: class_bindings }
-    = render partial: "projects/merge_requests/conflicts/inline_view", locals: { class_bindings: class_bindings }
+    .files
+      .diff-file.file-holder.conflict{"v-for" => "file in conflictsData.files"}
+        .file-title
+          %i.fa.fa-fw{":class" => "file.iconClass"}
+          %strong {{file.filePath}}
+          = render partial: 'projects/merge_requests/conflicts/file_actions'
+        .diff-content.diff-wrap-lines
+          .diff-wrap-lines.code.file-content.js-syntax-highlight{"v-show" => "!isParallel && file.resolveMode === 'interactive' && file.type === 'text'" }
+            = render partial: "projects/merge_requests/conflicts/components/inline_conflict_lines"
+          .diff-wrap-lines.code.file-content.js-syntax-highlight{"v-show" => "isParallel && file.resolveMode === 'interactive' && file.type === 'text'" }
+            = render partial: "projects/merge_requests/conflicts/components/parallel_conflict_lines"
+          %div{"v-show" => "file.resolveMode === 'edit' ||  file.type === 'text-editor'"}
+            = render partial: "projects/merge_requests/conflicts/components/diff_file_editor"
+
     = render partial: "projects/merge_requests/conflicts/submit_form"
+
+-# Components
+= render partial: 'projects/merge_requests/conflicts/components/parallel_conflict_line'
diff --git a/app/views/projects/merge_requests/conflicts/_commit_stats.html.haml b/app/views/projects/merge_requests/conflicts/_commit_stats.html.haml
index 457c467fba9..5ab3cd96163 100644
--- a/app/views/projects/merge_requests/conflicts/_commit_stats.html.haml
+++ b/app/views/projects/merge_requests/conflicts/_commit_stats.html.haml
@@ -1,20 +1,16 @@
 .content-block.oneline-block.files-changed{"v-if" => "!isLoading && !hasError"}
-  .inline-parallel-buttons
+  .inline-parallel-buttons{"v-if" => "showDiffViewTypeSwitcher"}
     .btn-group
-      %a.btn{ |
-        ":class" => "{'active': !isParallel}", |
-        "@click" => "handleViewTypeChange('inline')"}
+      %button.btn{":class" => "{'active': !isParallel}", "@click" => "handleViewTypeChange('inline')"}
         Inline
-      %a.btn{ |
-        ":class" => "{'active': isParallel}", |
-        "@click" => "handleViewTypeChange('parallel')"}
+      %button.btn{":class" => "{'active': isParallel}", "@click" => "handleViewTypeChange('parallel')"}
         Side-by-side
 
   .js-toggle-container
     .commit-stat-summary
       Showing
-      %strong.cred {{conflictsCount}} {{conflictsData.conflictsText}}
+      %strong.cred {{conflictsCountText}}
       between
-      %strong {{conflictsData.source_branch}}
+      %strong {{conflictsData.sourceBranch}}
       and
-      %strong {{conflictsData.target_branch}}
+      %strong {{conflictsData.targetBranch}}
diff --git a/app/views/projects/merge_requests/conflicts/_file_actions.html.haml b/app/views/projects/merge_requests/conflicts/_file_actions.html.haml
new file mode 100644
index 00000000000..05af57acf03
--- /dev/null
+++ b/app/views/projects/merge_requests/conflicts/_file_actions.html.haml
@@ -0,0 +1,12 @@
+.file-actions
+  .btn-group{"v-if" => "file.type === 'text'"}
+    %button.btn{ ":class" => "{ 'active': file.resolveMode == 'interactive' }",
+      '@click' => "onClickResolveModeButton(file, 'interactive')",
+      type: 'button' }
+      Interactive mode
+    %button.btn{ ':class' => "{ 'active': file.resolveMode == 'edit' }",
+      '@click' => "onClickResolveModeButton(file, 'edit')",
+      type: 'button' }
+      Edit inline
+  %a.btn.view-file.btn-file-option{":href" => "file.blobPath"}
+    View file @{{conflictsData.shortCommitSha}}
diff --git a/app/views/projects/merge_requests/conflicts/_inline_view.html.haml b/app/views/projects/merge_requests/conflicts/_inline_view.html.haml
deleted file mode 100644
index 19c7da4b5e3..00000000000
--- a/app/views/projects/merge_requests/conflicts/_inline_view.html.haml
+++ /dev/null
@@ -1,28 +0,0 @@
-.files{"v-show" => "!isParallel"}
-  .diff-file.file-holder.conflict.inline-view{"v-for" => "file in conflictsData.files"}
-    .file-title
-      %i.fa.fa-fw{":class" => "file.iconClass"}
-      %strong {{file.filePath}}
-      .file-actions
-        %a.btn.view-file.btn-file-option{":href" => "file.blobPath"}
-          View file @{{conflictsData.shortCommitSha}}
-
-    .diff-content.diff-wrap-lines
-      .diff-wrap-lines.code.file-content.js-syntax-highlight
-        %table
-          %tr.line_holder.diff-inline{"v-for" => "line in file.inlineLines"}
-            %template{"v-if" => "!line.isHeader"}
-              %td.diff-line-num.new_line{":class" => class_bindings}
-                %a {{line.new_line}}
-              %td.diff-line-num.old_line{":class" => class_bindings}
-                %a {{line.old_line}}
-              %td.line_content{":class" => class_bindings}
-                {{{line.richText}}}
-
-            %template{"v-if" => "line.isHeader"}
-              %td.diff-line-num.header{":class" => class_bindings}
-              %td.diff-line-num.header{":class" => class_bindings}
-              %td.line_content.header{":class" => class_bindings}
-                %strong {{{line.richText}}}
-                %button.btn{"@click" => "handleSelected(line.id, line.section)"}
-                  {{line.buttonTitle}}
diff --git a/app/views/projects/merge_requests/conflicts/_parallel_view.html.haml b/app/views/projects/merge_requests/conflicts/_parallel_view.html.haml
deleted file mode 100644
index 2e6f67c2eaf..00000000000
--- a/app/views/projects/merge_requests/conflicts/_parallel_view.html.haml
+++ /dev/null
@@ -1,27 +0,0 @@
-.files{"v-show" => "isParallel"}
-  .diff-file.file-holder.conflict.parallel-view{"v-for" => "file in conflictsData.files"}
-    .file-title
-      %i.fa.fa-fw{":class" => "file.iconClass"}
-      %strong {{file.filePath}}
-      .file-actions
-        %a.btn.view-file.btn-file-option{":href" => "file.blobPath"}
-          View file @{{conflictsData.shortCommitSha}}
-
-    .diff-content.diff-wrap-lines
-      .diff-wrap-lines.code.file-content.js-syntax-highlight
-        %table
-          %tr.line_holder.parallel{"v-for" => "section in file.parallelLines"}
-            %template{"v-for" => "line in section"}
-
-              %template{"v-if" => "line.isHeader"}
-                %td.diff-line-num.header{":class" => class_bindings}
-                %td.line_content.header{":class" => class_bindings}
-                  %strong {{line.richText}}
-                  %button.btn{"@click" => "handleSelected(line.id, line.section)"}
-                    {{line.buttonTitle}}
-
-              %template{"v-if" => "!line.isHeader"}
-                %td.diff-line-num.old_line{":class" => class_bindings}
-                  {{line.lineNumber}}
-                %td.line_content.parallel{":class" => class_bindings}
-                  {{{line.richText}}}
diff --git a/app/views/projects/merge_requests/conflicts/_submit_form.html.haml b/app/views/projects/merge_requests/conflicts/_submit_form.html.haml
index 78bd4133ea2..6ffaa9ad4d2 100644
--- a/app/views/projects/merge_requests/conflicts/_submit_form.html.haml
+++ b/app/views/projects/merge_requests/conflicts/_submit_form.html.haml
@@ -1,15 +1,16 @@
-.content-block.oneline-block.files-changed
-  %strong.resolved-count {{resolvedCount}}
-  of
-  %strong.total-count {{conflictsCount}}
-  conflicts have been resolved
-
-  .commit-message-container.form-group
-    .max-width-marker
-    %textarea.form-control.js-commit-message{"v-model" => "conflictsData.commitMessage"}
-      {{{conflictsData.commitMessage}}}
-
-  %button{type: "button", class: "btn btn-success js-submit-button", ":disabled" => "!readyToCommit", "@click" => "commit()"}
-    %span {{commitButtonText}}
-
-  = link_to "Cancel", namespace_project_merge_request_path(@merge_request.project.namespace, @merge_request.project, @merge_request), class: "btn btn-cancel"
+.form-horizontal.resolve-conflicts-form
+  .form-group
+    %label.col-sm-2.control-label{ "for" => "commit-message" }
+      Commit message
+    .col-sm-10
+      .commit-message-container
+        .max-width-marker
+        %textarea.form-control.js-commit-message#commit-message{ "v-model" => "conflictsData.commitMessage", "rows" => "5" }
+  .form-group
+    .col-sm-offset-2.col-sm-10
+      .row
+        .col-xs-6
+          %button{ type: "button", class: "btn btn-success js-submit-button", "@click" => "commit()", ":disabled" => "!readyToCommit" }
+            %span {{commitButtonText}}
+        .col-xs-6.text-right
+          = link_to "Cancel", namespace_project_merge_request_path(@merge_request.project.namespace, @merge_request.project, @merge_request), class: "btn btn-cancel"
diff --git a/app/views/projects/merge_requests/conflicts/components/_diff_file_editor.html.haml b/app/views/projects/merge_requests/conflicts/components/_diff_file_editor.html.haml
new file mode 100644
index 00000000000..3c927d362c2
--- /dev/null
+++ b/app/views/projects/merge_requests/conflicts/components/_diff_file_editor.html.haml
@@ -0,0 +1,13 @@
+%diff-file-editor{"inline-template" => "true", ":file" => "file", ":on-cancel-discard-confirmation" => "cancelDiscardConfirmation", ":on-accept-discard-confirmation" => "acceptDiscardConfirmation"}
+  .diff-editor-wrap{ "v-show" => "file.showEditor" }
+    .discard-changes-alert-wrap{ "v-if" => "file.promptDiscardConfirmation" }
+      .discard-changes-alert
+        Are you sure you want to discard your changes?
+        .discard-actions
+          %button.btn.btn-sm.btn-close{ "@click" => "acceptDiscardConfirmation(file)" } Discard changes
+          %button.btn.btn-sm{ "@click" => "cancelDiscardConfirmation(file)" } Cancel
+    .editor-wrap{ ":class" => "classObject" }
+      .loading
+        %i.fa.fa-spinner.fa-spin
+      .editor
+        %pre{ "style" => "height: 350px" }
diff --git a/app/views/projects/merge_requests/conflicts/components/_inline_conflict_lines.html.haml b/app/views/projects/merge_requests/conflicts/components/_inline_conflict_lines.html.haml
new file mode 100644
index 00000000000..f094df7fcaa
--- /dev/null
+++ b/app/views/projects/merge_requests/conflicts/components/_inline_conflict_lines.html.haml
@@ -0,0 +1,15 @@
+%inline-conflict-lines{ "inline-template" => "true", ":file" => "file"}
+  %table
+    %tr.line_holder.diff-inline{"v-for" => "line in file.inlineLines"}
+      %td.diff-line-num.new_line{":class" => "lineCssClass(line)", "v-if" => "!line.isHeader"}
+        %a {{line.new_line}}
+      %td.diff-line-num.old_line{":class" => "lineCssClass(line)", "v-if" => "!line.isHeader"}
+        %a {{line.old_line}}
+      %td.line_content{":class" => "lineCssClass(line)", "v-if" => "!line.isHeader"}
+        {{{line.richText}}}
+      %td.diff-line-num.header{":class" => "lineCssClass(line)", "v-if" => "line.isHeader"}
+      %td.diff-line-num.header{":class" => "lineCssClass(line)", "v-if" => "line.isHeader"}
+      %td.line_content.header{":class" => "lineCssClass(line)", "v-if" => "line.isHeader"}
+        %strong {{{line.richText}}}
+        %button.btn{ "@click" => "handleSelected(file, line.id, line.section)" }
+          {{line.buttonTitle}}
diff --git a/app/views/projects/merge_requests/conflicts/components/_parallel_conflict_line.html.haml b/app/views/projects/merge_requests/conflicts/components/_parallel_conflict_line.html.haml
new file mode 100644
index 00000000000..5690bf7419c
--- /dev/null
+++ b/app/views/projects/merge_requests/conflicts/components/_parallel_conflict_line.html.haml
@@ -0,0 +1,10 @@
+%script{"id" => 'parallel-conflict-line', "type" => "text/x-template"}
+  %td.diff-line-num.header{":class" => "lineCssClass(line)", "v-if" => "line.isHeader"}
+  %td.line_content.header{":class" => "lineCssClass(line)", "v-if" => "line.isHeader"}
+    %strong {{line.richText}}
+    %button.btn{"@click" => "handleSelected(file, line.id, line.section)"}
+      {{line.buttonTitle}}
+  %td.diff-line-num.old_line{":class" => "lineCssClass(line)", "v-if" => "!line.isHeader"}
+    {{line.lineNumber}}
+  %td.line_content.parallel{":class" => "lineCssClass(line)", "v-if" => "!line.isHeader"}
+    {{{line.richText}}}
diff --git a/app/views/projects/merge_requests/conflicts/components/_parallel_conflict_lines.html.haml b/app/views/projects/merge_requests/conflicts/components/_parallel_conflict_lines.html.haml
new file mode 100644
index 00000000000..a8ecdf59393
--- /dev/null
+++ b/app/views/projects/merge_requests/conflicts/components/_parallel_conflict_lines.html.haml
@@ -0,0 +1,4 @@
+%parallel-conflict-lines{"inline-template" => "true", ":file" => "file"}
+  %table
+    %tr.line_holder.parallel{"v-for" => "section in file.parallelLines"}
+      %td{"is"=>"parallel-conflict-line", "v-for" => "line in section", ":line" => "line", ":file" => "file"}
diff --git a/app/workers/expire_build_instance_artifacts_worker.rb b/app/workers/expire_build_instance_artifacts_worker.rb
index 916c2e633c1..d9e2cc37bb3 100644
--- a/app/workers/expire_build_instance_artifacts_worker.rb
+++ b/app/workers/expire_build_instance_artifacts_worker.rb
@@ -2,10 +2,14 @@ class ExpireBuildInstanceArtifactsWorker
   include Sidekiq::Worker
 
   def perform(build_id)
-    build = Ci::Build.with_expired_artifacts.reorder(nil).find_by(id: build_id)
-    return unless build
+    build = Ci::Build
+      .with_expired_artifacts
+      .reorder(nil)
+      .find_by(id: build_id)
 
-    Rails.logger.info "Removing artifacts build #{build.id}..."
+    return unless build.try(:project)
+
+    Rails.logger.info "Removing artifacts for build #{build.id}..."
     build.erase_artifacts!
   end
 end