fix: ignore failed outline API call when learner has no access

[pwnage101]

If the learner doesn't even have access to the course (e.g. because the course starts in the future), don't worry about a 404 fetching the course outline since we're not planning to use it anyway.

ENT-8078

matrix

• [current behavior] if the learner has access to the course and tab data is available: stay on course home page.
• [current behavior] if the learner has access to the course but the tab data is not available, display error page.
• [current behavior] if the learner does not have access to the course, but the tab data is available, dispatch to enterprise redirect logic.
• [NEW BEHAVIOR] if the learner does not have access to the course, but the tab data is not available, dispatch to enterprise redirect logic (WAS: display error page).

A combination of factors contribute to this specific scenario with new behavior, but the vast majority of hits on this page won't trigger this scenario. It just so happens that it's likely to happen while testing on stage, which gets in the way of testing other features which rely on dispatching to fetchTabDenied.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (4928f50) 88.29% compared to head (1cea8cd) 88.33%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1259      +/-   ##
==========================================
+ Coverage   88.29%   88.33%   +0.03%     
==========================================
  Files         291      291              
  Lines        4923     4930       +7     
  Branches     1239     1242       +3     
==========================================
+ Hits         4347     4355       +8     
+ Misses        562      561       -1     
  Partials       14       14              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[pwnage101]

Notable changes:

• There's now a default case; one of [fetchTabDenied, fetchTabSuccess, fetchTabFailure] is always dispatched.
• A non-accessible course is now handled using fetchTabDenied regardless of the tab data query results.

[adamstankiewicz]

LGTM (with a couple nits), deferring to any owning squad's review feedback.

[adamstankiewicz]

nit: I wonder if it'd make sense to co-locate the conditions that result in throwing an exception?

if (courseHomeCourseMetadataResult.status === 'rejected') {
  throw courseHomeCourseMetadataResult.reason;
} else if (tabDataResult?.status === 'rejected') {
  throw tabDataResult.reason;
} else if (!courseHomeCourseMetadataResult.value.courseAccess.hasAccess) {
 dispatch(fetchTabDenied({ courseId }));
} else {
  dispatch(fetchTabSuccess({
    courseId,
    targetUserId,
  }));
}

[pwnage101]

Hm, I'm pretty sure I want to dispatch fetchTabDenied as soon as possible, which is why the conditional is ordered like that. I added a comment to clarify this.