refactor: replace ad-hoc structure with GitLabComment class

The GitLabComment is going to be responsible for all comment-related
functionality like editing, deleting and reacting.

src/data_providers/items/mr_item_model.ts

@@ -11,6 +11,7 @@ import {
 } from '../../gitlab/gitlab_new_service';
 import { handleError } from '../../log';
 import { UserFriendlyError } from '../../errors/user_friendly_error';
+import { GitLabComment } from '../../review/gitlab_comment';
 
 const isTextDiffDiscussion = (discussion: GqlDiscussion): discussion is GqlTextDiffDiscussion => {
   const firstNote = discussion.notes.nodes[0];
@@ -90,14 +91,7 @@ export class MrItemModel extends ItemModel {
     });
     const discussionsOnDiff = discussions.filter(isTextDiffDiscussion);
     const threads = discussionsOnDiff.map(({ notes }) => {
-      const comments = notes.nodes.map(({ body, author }) => ({
-        body,
-        mode: vscode.CommentMode.Preview,
-        author: {
-          name: author.name,
-          iconPath: author.avatarUrl !== null ? vscode.Uri.parse(author.avatarUrl) : undefined,
-        },
-      }));
+      const comments = notes.nodes.map(GitLabComment.fromGqlNote);
       const { position } = notes.nodes[0];
       const thread = commentController.createCommentThread(
         this.uriFromPosition(position),

src/gitlab/gitlab_new_service.ts

@@ -100,6 +100,7 @@ interface GqlGenericDiscussion<T extends GqlBasePosition | null> {
   notes: Node<GqlGenericNote<T>>;
 }
 
+export type GqlTextDiffNote = GqlGenericNote<GqlTextPosition>;
 export type GqlTextDiffDiscussion = GqlGenericDiscussion<GqlTextPosition>;
 
 export type GqlDiscussion =

src/review/gitlab_comment.ts

+import * as vscode from 'vscode';
+import { GqlTextDiffNote } from '../gitlab/gitlab_new_service';
+
+export class GitLabComment implements vscode.Comment {
+  protected constructor(readonly gqlNote: GqlTextDiffNote, public mode: vscode.CommentMode) {}
+
+  get author(): vscode.CommentAuthorInformation {
+    const { name, avatarUrl } = this.gqlNote.author;
+    return {
+      name,
+      iconPath: avatarUrl !== null ? vscode.Uri.parse(avatarUrl) : undefined,
+    };
+  }
+
+  get body(): string {
+    return this.gqlNote.body;
+  }
+
+  static fromGqlNote(gqlNote: GqlTextDiffNote): GitLabComment {
+    return new GitLabComment(gqlNote, vscode.CommentMode.Preview);
+  }
+}