refactor: show commenting range for old MR diff file

src/data_providers/items/changed_file_item.ts

 import { TreeItem, Uri } from 'vscode';
 import { posix as path } from 'path';
-import { toReviewUri } from '../../review/review_uri';
+import { toReviewUri, ReviewParams } from '../../review/review_uri';
 import { PROGRAMMATIC_COMMANDS, VS_COMMANDS } from '../../command_names';
 import { ADDED, DELETED, RENAMED, MODIFIED } from '../../constants';
 
@@ -63,23 +63,25 @@ export class ChangedFileItem extends TreeItem {
       };
       return;
     }
-
-    const emptyFileUri = toReviewUri({ workspacePath: workspace.uri, projectId: mr.project_id });
+    const commonParams: ReviewParams = {
+      workspacePath: workspace.uri,
+      projectId: mr.project_id,
+      mrId: mr.id,
+    };
+    const emptyFileUri = toReviewUri(commonParams);
     const baseFileUri = file.new_file
       ? emptyFileUri
       : toReviewUri({
+          ...commonParams,
           path: file.old_path,
           commit: mrVersion.base_commit_sha,
-          workspacePath: workspace.uri,
-          projectId: mr.project_id,
         });
     const headFileUri = file.deleted_file
       ? emptyFileUri
       : toReviewUri({
+          ...commonParams,
           path: file.new_path,
           commit: mrVersion.head_commit_sha,
-          workspacePath: workspace.uri,
-          projectId: mr.project_id,
         });
 
     this.command = {

src/data_providers/items/mr_item_model.ts

@@ -7,6 +7,7 @@ import { GqlDiscussion, GqlTextDiffDiscussion } from '../../gitlab/gitlab_new_se
 import { handleError } from '../../log';
 import { UserFriendlyError } from '../../errors/user_friendly_error';
 import { GitLabCommentThread } from '../../review/gitlab_comment_thread';
+import { CommentingRangeProvider } from '../../review/commenting_range_provider';
 
 const isTextDiffDiscussion = (discussion: GqlDiscussion): discussion is GqlTextDiffDiscussion => {
   const firstNote = discussion.notes.nodes[0];
@@ -38,8 +39,10 @@ export class MrItemModel extends ItemModel {
       arguments: [this.mr, this.workspace.uri],
       title: 'Show MR Overview',
     };
+    const gitlabService = await createGitLabNewService(this.workspace.uri);
+    const mrVersion = await gitlabService.getMrDiff(this.mr);
     try {
-      await this.getMrDiscussions();
+      await this.getMrDiscussions(mrVersion);
     } catch (e) {
       handleError(
         new UserFriendlyError(
@@ -50,16 +53,21 @@ export class MrItemModel extends ItemModel {
         ),
       );
     }
-    const changedFiles = await this.getChangedFiles();
+
+    const changedFiles = mrVersion.diffs.map(
+      d => new ChangedFileItem(this.mr, mrVersion, d, this.workspace),
+    );
     return [overview, ...changedFiles];
   }
 
-  private async getMrDiscussions(): Promise<void> {
+  private async getMrDiscussions(mrVersion: RestMrVersion): Promise<void> {
     const commentController = vscode.comments.createCommentController(
       this.mr.references.full,
       this.mr.title,
     );
 
+    commentController.commentingRangeProvider = new CommentingRangeProvider(this.mr, mrVersion);
+
     const gitlabService = await createGitLabNewService(this.workspace.uri);
 
     const discussions = await gitlabService.getDiscussions({
@@ -77,10 +85,4 @@ export class MrItemModel extends ItemModel {
     });
     this.setDisposableChildren([...threads, commentController]);
   }
-
-  private async getChangedFiles(): Promise<vscode.TreeItem[]> {
-    const gitlabService = await createGitLabNewService(this.workspace.uri);
-    const mrVersion = await gitlabService.getMrDiff(this.mr);
-    return mrVersion.diffs.map(d => new ChangedFileItem(this.mr, mrVersion, d, this.workspace));
-  }
 }

src/review/commenting_range_provider.test.ts

+import * as vscode from 'vscode';
+import { mr, mrVersion } from '../test_utils/entities';
+import { CommentingRangeProvider } from './commenting_range_provider';
+import { toReviewUri } from './review_uri';
+
+describe('CommentingRangeProvider', () => {
+  let commentingRangeProvider: CommentingRangeProvider;
+
+  beforeEach(() => {
+    commentingRangeProvider = new CommentingRangeProvider(mr, mrVersion);
+  });
+
+  it('returns empty array for different URI schema', () => {
+    const testDocument = {
+      uri: vscode.Uri.parse('https://example.com'),
+    } as vscode.TextDocument;
+    expect(commentingRangeProvider.provideCommentingRanges(testDocument)).toEqual([]);
+  });
+
+  it('returns full range (all lines in the document) for old file', () => {
+    const testDocument = {
+      uri: toReviewUri({
+        path: `/path`,
+        mrId: mr.id,
+        projectId: mr.project_id,
+        commit: mrVersion.base_commit_sha,
+        workspacePath: '/',
+      }),
+      lineCount: 200,
+    } as vscode.TextDocument;
+    expect(commentingRangeProvider.provideCommentingRanges(testDocument)).toEqual([
+      new vscode.Range(new vscode.Position(0, 0), new vscode.Position(199, 0)),
+    ]);
+  });
+
+  it('returns empty array for new file', () => {
+    const testDocument = {
+      uri: toReviewUri({
+        path: `/path`,
+        mrId: mr.id,
+        projectId: mr.project_id,
+        commit: mrVersion.head_commit_sha,
+        workspacePath: '/',
+      }),
+      lineCount: 200,
+    } as vscode.TextDocument;
+    expect(commentingRangeProvider.provideCommentingRanges(testDocument)).toEqual([]);
+  });
+});

src/review/commenting_range_provider.ts

+import * as vscode from 'vscode';
+import { REVIEW_URI_SCHEME } from '../constants';
+import { fromReviewUri } from './review_uri';
+
+export class CommentingRangeProvider implements vscode.CommentingRangeProvider {
+  private mr: RestIssuable;
+
+  private mrVersion: RestMrVersion;
+
+  constructor(mr: RestIssuable, mrVersion: RestMrVersion) {
+    this.mr = mr;
+    this.mrVersion = mrVersion;
+  }
+
+  provideCommentingRanges(document: vscode.TextDocument): vscode.Range[] {
+    const { uri } = document;
+    if (uri.scheme !== REVIEW_URI_SCHEME) return [];
+    const params = fromReviewUri(uri);
+    if (params.mrId !== this.mr.id || params.projectId !== this.mr.project_id || !params.path) {
+      return [];
+    }
+    const oldFile = params.commit === this.mrVersion.base_commit_sha;
+    if (oldFile) {
+      return [
+        new vscode.Range(new vscode.Position(0, 0), new vscode.Position(document.lineCount - 1, 0)),
+      ];
+    }
+
+    return [];
+  }
+}

src/review/git_content_provider.test.ts

@@ -14,6 +14,7 @@ describe('GitContentProvider', () => {
     commit: 'abcdef',
     path: '/review',
     projectId: 1234,
+    mrId: 2345,
     workspacePath: 'path/to/workspace',
   };
 

src/review/gitlab_comment_thread.ts

@@ -30,6 +30,7 @@ const uriFromPosition = (
   position: GqlTextPosition,
   workspaceFolder: string,
   gitlabProjectId: number,
+  mrId: number,
 ) => {
   const onOldVersion = position.oldLine !== null;
   const path = onOldVersion ? position.oldPath : position.newPath;
@@ -39,6 +40,7 @@ const uriFromPosition = (
     commit,
     workspacePath: workspaceFolder,
     projectId: gitlabProjectId,
+    mrId,
   });
 };
 
@@ -152,7 +154,7 @@ export class GitLabCommentThread {
   }: CreateThreadOptions): GitLabCommentThread {
     const { position } = firstNoteFrom(discussion);
     const vsThread = commentController.createCommentThread(
-      uriFromPosition(position, workspaceFolder, mr.project_id),
+      uriFromPosition(position, workspaceFolder, mr.project_id, mr.id),
       commentRangeFromPosition(position),
       // the comments need to know about the thread, so we first
       // create empty thread to be able to create comments

src/review/review_uri.test.ts

@@ -5,6 +5,7 @@ describe('review_uri.ts', () => {
     commit: 'abcdef',
     path: '/review',
     projectId: 1234,
+    mrId: 2345,
     workspacePath: 'path/to/workspace',
   };
 
@@ -13,7 +14,7 @@ describe('review_uri.ts', () => {
       const result = toReviewUri(reviewUriParams);
 
       expect(result.toString()).toEqual(
-        'gl-review:///review{"commit":"abcdef","workspacePath":"path/to/workspace","projectId":1234}#',
+        'gl-review:///review{"commit":"abcdef","mrId":2345,"projectId":1234,"workspacePath":"path/to/workspace"}#',
       );
     });
   });

src/review/review_uri.ts

 import { Uri } from 'vscode';
 import { REVIEW_URI_SCHEME } from '../constants';
 
-interface ReviewParams {
+export interface ReviewParams {
   path?: string;
   commit?: string;
   workspacePath: string;
   projectId: number;
+  mrId: number;
 }
 
-export function toReviewUri({ path = '', commit, workspacePath, projectId }: ReviewParams): Uri {
+export function toReviewUri({
+  path = '',
+  commit,
+  workspacePath,
+  projectId,
+  mrId,
+}: ReviewParams): Uri {
+  const query = { commit, workspacePath, projectId, mrId };
   return Uri.file(path).with({
     scheme: REVIEW_URI_SCHEME,
-    query: JSON.stringify({ commit, workspacePath, projectId }),
+    query: JSON.stringify(query, Object.keys(query).sort()),
   });
 }
 
 export function fromReviewUri(uri: Uri): ReviewParams {
-  const { commit, workspacePath, projectId } = JSON.parse(uri.query);
+  const { commit, workspacePath, projectId, mrId } = JSON.parse(uri.query);
   return {
     path: uri.path || undefined,
     commit,
     workspacePath,
     projectId,
+    mrId,
   };
 }