Summary:
All links in SourceCred must use the `Link` component, providing either
an external URL `href={…}` or an internal route `to={…}`. Any uses of a
raw `<a>` element for internal routes will incur 404s when the
application is hosted on a non-root path, as is currently the case on
the production website.
The change to `FileUploader` is not strictly necessary, as the link has
no styled text and uses a `data:` URL, but there’s no reason not to.
Fixes#1304.
Test Plan:
Build the static site:
```
scripts/build_static_site.sh --target cred --project sourcecred/example-github
```
Then run `python3 -m http.server` from the repository root directory—not
the `cred/` subdirectory—and navigate to the timeline cred view:
<http://localhost:8000/cred/timeline/sourcecred/example-github/>
Observe that the “(legacy)” link now has the correct styling and
correctly navigates to the legacy mode page when clicked: prior to this
change, it would navigate to a URL without the proper `/cred/` path
prefix, yielding a 404. On the legacy page, verify that the “timeline
mode” link has the same properties.
Then, visit <http://localhost:8000/cred/test/FileUploader/> and verify
that the inspection test still passes.
Added a regression test to catch further such errors. Note that
reverting the code changes in this commit causes the test to fail, and
that running it with `--verbose` prints the problematic files.
wchargin-branch: fix-bad-routing-404s