test(frontend): cover the remaining lines and branches in the coeditor icon, venv page, files uploader and preset wrapper

[mengw15]

What changes were proposed in this PR?

Covers the remaining lines and untaken branches in the four files. All four now
report full line and branch coverage. No production code was changed.

Two of the paths in the issue have moved: CoeditorUserIconComponent lives under
workspace/component/menu/, and PresetWrapperComponent under
common/formly/.

CoeditorUserIconComponent (+5) — the shadowing menu had no test at all
beyond "should create". Both arms of the compound guard now render: shadowing
off, shadowing on for another co-editor (the second half flipped on its own),
and shadowing on for this one. Each variant is then clicked, asserting the
presence service receives shadowCoeditor / stopShadowing.

UserVenvComponent (+5) — the "(unnamed)" fallback on both the confirm
dialog and the delete notification, a record with no packages, a stored
version that is nullish rather than empty (only nullish reaches ?? ""), and a
draft row whose version is null.

FilesUploaderComponent (+5) — the existing suite constructs the component
with new, so the template had never rendered (0% on the .html). A second block
mounts it for real and drives the banner *ngIf through all four flag
combinations, its message, its close handler, the drop-zone button and the drop
handler.

PresetWrapperComponent (+6) — a form control holding a value and holding
null, setupFieldConfig, the applyPresetStream predicate with a matching and
a non-matching event plus the basePreset assignment behind it, and the
dropdown's own nzVisibleChange output.

Two notes on how the DOM is driven here:

• nz-dropdown-menu keeps its content in an ng-template that mounts into a CDK
  overlay only when the dropdown opens, which jsdom does not drive. Rather than
  assert on the bound data, the tests instantiate that template directly
  (viewContainerRef.createEmbeddedView(templateRef)), which puts the rows in
  the fixture's DOM so the *ngFor, the interpolations and the click handlers
  all really run. This replaces the data-only assertions the preset spec had for
  the same reason.
• PresetWrapperComponent's "does not refresh while the dropdown is closed" test
  never awaited the handler's debounceTime(0), so it passed because the
  callback had not run yet rather than because the menu was closed — it could not
  fail. It now awaits the tick and also asserts the search term is still tracked.

ngx-file-drop hands its openFileSelector to the content template by
reference, so a spy installed after render is not seen; that test asserts the
effect (the hidden file input is clicked) instead.

Any related issues, documentation, discussions?

Closes #7700

How was this PR tested?

Extended unit tests, run locally in frontend/ (all green; the failure paths
were verified by breaking one assertion per file and confirming all four suites
go red and the run exits non-zero):

ng test --watch=false --include <the four specs>
# Test Files 4 passed (4) | Tests 111 passed (111)
prettier --write <specs>   # clean
eslint  <specs>            # clean

The coverage report was re-run over the four specs to confirm the gaps cleared —
coeditor-user-icon.component.{ts,html}, user-venv.component.ts,
files-uploader.component.{ts,html} and preset-wrapper.component.{ts,html}
each report no unhit line and no partial branch.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Code (Opus 4.8 [1M context])

[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @gupta-sahil01, @Yicong-Huang
  You can notify them by mentioning @gupta-sahil01, @Yicong-Huang in a comment.

[Copilot]

Pull request overview

Extends frontend unit tests to achieve full line and branch coverage for four components without production-code changes.

Changes:

• Covers remaining conditional and nullish-value branches.
• Adds rendered-template interaction tests for dropdowns, alerts, file selection, and preset actions.
• Corrects an asynchronous preset test to await its debounced handler.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
coeditor-user-icon.component.spec.ts	Tests shadowing menu states and actions.
user-venv.component.spec.ts	Tests missing packages, null versions, and unnamed environments.
files-uploader.component.spec.ts	Tests rendered banner and file-drop controls.
preset-wrapper.component.spec.ts	Tests initialization, streams, configuration, and dropdown interactions.

---

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.93%. Comparing base (363537e) to head (b4040e9).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #7701      +/-   ##
============================================
+ Coverage     90.87%   90.93%   +0.05%     
  Complexity     4450     4450              
============================================
  Files          1175     1175              
  Lines         47140    47140              
  Branches       5284     5284              
============================================
+ Hits          42839    42866      +27     
+ Misses         2598     2582      -16     
+ Partials       1703     1692      -11     

Flag	Coverage Δ		*Carryforward flag
access-control-service	81.00% <ø> (ø)		Carriedforward from 363537e
agent-service	98.62% <ø> (ø)		Carriedforward from 363537e
amber	87.37% <ø> (ø)		Carriedforward from 363537e
computing-unit-managing-service	73.67% <ø> (ø)		Carriedforward from 363537e
config-service	86.73% <ø> (ø)		Carriedforward from 363537e
file-service	68.90% <ø> (ø)		Carriedforward from 363537e
frontend	92.44% <ø> (+0.13%)	⬆️
notebook-migration-service	83.74% <ø> (ø)		Carriedforward from 363537e
pyamber	97.57% <ø> (ø)		Carriedforward from 363537e
workflow-compiling-service	77.19% <ø> (ø)		Carriedforward from 363537e

*This pull request uses carry forward flags. Click here to find out more.

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