From b8d8d405c2ae5785b8de4ab9aa4c0367204f44d7 Mon Sep 17 00:00:00 2001
From: Thomas Randolph <trandolph@gitlab.com>
Date: Wed, 8 Mar 2023 01:16:43 -0700
Subject: [PATCH] Add helper to get the file ID from the URL hash

---
 app/assets/javascripts/diffs/store/utils.js | 29 ++++++++++++++
 spec/frontend/diffs/store/utils_spec.js     | 44 +++++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/app/assets/javascripts/diffs/store/utils.js b/app/assets/javascripts/diffs/store/utils.js
index 0519ca3d7151e6..84a2af6c5936d2 100644
--- a/app/assets/javascripts/diffs/store/utils.js
+++ b/app/assets/javascripts/diffs/store/utils.js
@@ -19,6 +19,8 @@ import {
 } from '../constants';
 import { prepareRawDiffFile } from '../utils/diff_file';
 
+const SHA1 = /\b([a-f0-9]{40})\b/;
+
 export const isAdded = (line) => ['new', 'new-nonewline'].includes(line.type);
 export const isRemoved = (line) => ['old', 'old-nonewline'].includes(line.type);
 export const isUnchanged = (line) => !line.type;
@@ -556,3 +558,30 @@ export const allDiscussionWrappersExpanded = (diff) => {
 
   return discussionsExpanded;
 };
+
+export function isUrlHashNoteLink(urlHash) {
+  const id = urlHash.replace(/^#/, '');
+
+  return id.startsWith('note');
+}
+
+export function isUrlHashFileHeader(urlHash) {
+  const id = urlHash.replace(/^#/, '');
+
+  return id.startsWith('diff-content');
+}
+
+export function parseUrlHashAsFileHash(urlHash, currentDiffFileId = '') {
+  const isNoteLink = isUrlHashNoteLink(urlHash);
+  let id = urlHash.replace(/^#/, '');
+
+  if (isNoteLink && currentDiffFileId) {
+    id = currentDiffFileId;
+  } else if (isUrlHashFileHeader(urlHash)) {
+    id = id.replace('diff-content-', '');
+  } else if (!SHA1.test(id) || isNoteLink) {
+    id = null;
+  }
+
+  return id;
+}
diff --git a/spec/frontend/diffs/store/utils_spec.js b/spec/frontend/diffs/store/utils_spec.js
index b5c44b084d8b90..68bbbdbe17637a 100644
--- a/spec/frontend/diffs/store/utils_spec.js
+++ b/spec/frontend/diffs/store/utils_spec.js
@@ -892,4 +892,48 @@ describe('DiffsStoreUtils', () => {
       expect(files[6].right).toBeNull();
     });
   });
+
+  describe('isUrlHashNoteLink', () => {
+    it.each`
+      input            | bool
+      ${'#note_12345'} | ${true}
+      ${'#12345'}      | ${false}
+      ${'note_12345'}  | ${true}
+      ${'12345'}       | ${false}
+    `('returns $bool for $input', ({ bool, input }) => {
+      expect(utils.isUrlHashNoteLink(input)).toBe(bool);
+    });
+  });
+
+  describe('isUrlHashFileHeader', () => {
+    it.each`
+      input                    | bool
+      ${'#diff-content-12345'} | ${true}
+      ${'#12345'}              | ${false}
+      ${'diff-content-12345'}  | ${true}
+      ${'12345'}               | ${false}
+    `('returns $bool for $input', ({ bool, input }) => {
+      expect(utils.isUrlHashFileHeader(input)).toBe(bool);
+    });
+  });
+
+  describe('parseUrlHashAsFileHash', () => {
+    it.each`
+      input                                          | currentDiffId | resultId
+      ${'#note_12345'}                               | ${'1A2B3C'}   | ${'1A2B3C'}
+      ${'note_12345'}                                | ${'1A2B3C'}   | ${'1A2B3C'}
+      ${'#note_12345'}                               | ${undefined}  | ${null}
+      ${'note_12345'}                                | ${undefined}  | ${null}
+      ${'#diff-content-12345'}                       | ${undefined}  | ${'12345'}
+      ${'diff-content-12345'}                        | ${undefined}  | ${'12345'}
+      ${'#diff-content-12345'}                       | ${'98765'}    | ${'12345'}
+      ${'diff-content-12345'}                        | ${'98765'}    | ${'12345'}
+      ${'#e334a2a10f036c00151a04cea7938a5d4213a818'} | ${undefined}  | ${'e334a2a10f036c00151a04cea7938a5d4213a818'}
+      ${'e334a2a10f036c00151a04cea7938a5d4213a818'}  | ${undefined}  | ${'e334a2a10f036c00151a04cea7938a5d4213a818'}
+      ${'#Z334a2a10f036c00151a04cea7938a5d4213a818'} | ${undefined}  | ${null}
+      ${'Z334a2a10f036c00151a04cea7938a5d4213a818'}  | ${undefined}  | ${null}
+    `('returns $resultId for $input and $currentDiffId', ({ input, currentDiffId, resultId }) => {
+      expect(utils.parseUrlHashAsFileHash(input, currentDiffId)).toBe(resultId);
+    });
+  });
 });
-- 
GitLab