fix(ui): handle out-of-bounds end line in code selection (#4788)

- fallback to the last line, preventing TypeError
- add E2E test

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/4788
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Solomon Victorino <git@solomonvictorino.com>
Co-committed-by: Solomon Victorino <git@solomonvictorino.com>

tests/e2e/repo-code.test.e2e.js

@@ -0,0 +1,53 @@
+// @ts-check
+import {test, expect} from '@playwright/test';
+import {login_user, load_logged_in_context} from './utils_e2e.js';
+
+test.beforeAll(async ({browser}, workerInfo) => {
+  await login_user(browser, workerInfo, 'user2');
+});
+
+async function assertSelectedLines(page, nums) {
+  const pageAssertions = async () => {
+    expect(
+      await Promise.all((await page.locator('tr.active [data-line-number]').all()).map((line) => line.getAttribute('data-line-number'))),
+    )
+      .toStrictEqual(nums);
+
+    // the first line selected has an action button
+    if (nums.length > 0) await expect(page.locator(`#L${nums[0]} .code-line-button`)).toBeVisible();
+  };
+
+  await pageAssertions();
+
+  // URL has the expected state
+  expect(new URL(page.url()).hash)
+    .toEqual(nums.length === 0 ? '' : nums.length === 1 ? `#L${nums[0]}` : `#L${nums[0]}-L${nums.at(-1)}`);
+
+  // test selection restored from URL hash
+  await page.reload();
+  return pageAssertions();
+}
+
+test('Line Range Selection', async ({browser}, workerInfo) => {
+  const context = await load_logged_in_context(browser, workerInfo, 'user2');
+  const page = await context.newPage();
+
+  const filePath = '/user2/repo1/src/branch/master/README.md?display=source';
+
+  const response = await page.goto(filePath);
+  await expect(response?.status()).toBe(200);
+
+  await assertSelectedLines(page, []);
+  await page.locator('span#L1').click();
+  await assertSelectedLines(page, ['1']);
+  await page.locator('span#L3').click({modifiers: ['Shift']});
+  await assertSelectedLines(page, ['1', '2', '3']);
+  await page.locator('span#L2').click();
+  await assertSelectedLines(page, ['2']);
+  await page.locator('span#L1').click({modifiers: ['Shift']});
+  await assertSelectedLines(page, ['1', '2']);
+
+  // out-of-bounds end line
+  await page.goto(`${filePath}#L1-L100`);
+  await assertSelectedLines(page, ['1', '2', '3']);
+});

web_src/js/features/repo-code.js

@@ -158,7 +158,8 @@ export function initRepoCodeView() {
       if (m) {
         $first = $linesEls.filter(`[rel=${m[1]}]`);
         if ($first.length) {
-          selectRange($linesEls, $first, $linesEls.filter(`[rel=${m[2]}]`));
+          const $last = $linesEls.filter(`[rel=${m[2]}]`);
+          selectRange($linesEls, $first, $last.length ? $last : $linesEls.last());
 
           // show code view menu marker (don't show in blame page)
           if (!isBlame()) {