refactor: extract methods for parsing GqlPosition

src/review/gitlab_comment_thread.ts

@@ -5,6 +5,7 @@ import { GitLabComment } from './gitlab_comment';
 import { toReviewUri } from './review_uri';
 import { GqlTextDiffDiscussion } from '../gitlab/graphql/get_discussions';
 import { GqlNote, GqlTextDiffNote, GqlTextPosition } from '../gitlab/graphql/shared';
+import { commitFromPosition, pathFromPosition } from './gql_position_parser';
 
 const firstNoteFrom = (discussion: GqlTextDiffDiscussion): GqlTextDiffNote => {
   const note = discussion.notes.nodes[0];
@@ -22,13 +23,6 @@ const commentRangeFromPosition = (position: GqlTextPosition): vscode.Range => {
   return new vscode.Range(vsPosition, vsPosition);
 };
 
-const pathAndCommitFromPosition = (position: GqlTextPosition) => {
-  const onOldVersion = position.oldLine !== null;
-  const path = onOldVersion ? position.oldPath : position.newPath;
-  const commit = onOldVersion ? position.diffRefs.baseSha : position.diffRefs.headSha;
-  return { path, commit };
-};
-
 interface CreateThreadOptions {
   commentController: vscode.CommentController;
   repositoryRoot: string;
@@ -141,7 +135,8 @@ export class GitLabCommentThread {
     const { position } = firstNoteFrom(discussion);
     const vsThread = commentController.createCommentThread(
       toReviewUri({
-        ...pathAndCommitFromPosition(position),
+        path: pathFromPosition(position),
+        commit: commitFromPosition(position),
         repositoryRoot,
         projectId: mr.project_id,
         mrId: mr.id,

src/review/gql_position_parser.test.ts

+import { commitFromPosition, pathFromPosition } from './gql_position_parser';
+import { noteOnDiff } from '../../test/integration/fixtures/graphql/discussions.js';
+import { GqlTextPosition } from '../gitlab/graphql/shared';
+
+const { position } = noteOnDiff;
+
+const oldPosition = {
+  ...position,
+  oldLine: 1,
+  newLine: null,
+  oldPath: 'oldPath.js',
+  diffRefs: {
+    ...position.diffRefs,
+    baseSha: 'abcd',
+  },
+} as GqlTextPosition;
+
+const newPosition = {
+  ...position,
+  oldLine: null,
+  newLine: 1,
+  newPath: 'newPath.js',
+  diffRefs: {
+    ...position.diffRefs,
+    headSha: '1234',
+  },
+} as GqlTextPosition;
+
+describe('pathFromPosition', () => {
+  it('returns old path for old position', () => {
+    expect(pathFromPosition(oldPosition)).toBe('oldPath.js');
+  });
+  it('returns new path for new position', () => {
+    expect(pathFromPosition(newPosition)).toBe('newPath.js');
+  });
+});
+
+describe('commitFromPosition', () => {
+  it('returns baseSha for old position', () => {
+    expect(commitFromPosition(oldPosition)).toBe('abcd');
+  });
+  it('returns headSha for new position', () => {
+    expect(commitFromPosition(newPosition)).toBe('1234');
+  });
+});

src/review/gql_position_parser.ts

+import { GqlTextPosition } from '../gitlab/graphql/shared';
+
+const isOld = (position: GqlTextPosition) => position.oldLine !== null;
+
+export const pathFromPosition = (position: GqlTextPosition): string => {
+  return isOld(position) ? position.oldPath : position.newPath;
+};
+
+export const commitFromPosition = (position: GqlTextPosition): string => {
+  return isOld(position) ? position.diffRefs.baseSha : position.diffRefs.headSha;
+};