umputun / remark42 / 33314716797

85%

master: 85%

Build Type

Pull #2239

github

Committed by paskal

Commit Message

Remove the jest cases the browser suite already asserts

The e2e suite drives the real widget and now reports what it reaches, so the
cases it duplicates are two tests of one behaviour: one of them fails when the
widget breaks and the other tells nobody anything new.

The rule is narrower than coverage. A case goes only when a named e2e case
asserts the same behaviour, and the unit of the decision is the assertion, not
the case: a case that asserts a control renders and that its countdown reads
300s needs both covered, and the browser suite only waits for that element to
appear. Coverage rules candidates out, never in, since a component renders
during unrelated tests and marks its lines covered while nothing checks it.

Twenty-four cases go, across nine suites. The largest share is comment.test.tsx,
whose cases were almost all "does this element render", which a click proves:
Playwright refuses to click a control that is missing, hidden or disabled, and
renaming the Vote up title makes TestVote_UpvoteCountsOnce fail at its click.

Thirty-three suites give up nothing. They assert redux actions, spy call
counts, postMessage payloads, execCommand calls, CSS module class names, refs
and icon dimensions, none of which the browser suite asserts and most of which
it should not: asserting a request and its response is the better test of the
same thing.

Checked by measurement: with these cases gone jest covers no line it covered
before that the browser suite does not also cover. That check caught one
unsound deletion, the auth dropdown ignoring a clickOutside whose source is not
window.parent, which no browser case reaches because the only such message the
suite sends comes from the real parent and takes another branch.

Line coverage cannot catch every kind of mistake, and two more came out of
review. Hide rendering for an ordinary reader on another reader's comment was
restored: TestThread_HideUserRemovesTheirCommentsOnly clicks Hide as the dev
user, which ... (continued)

Pull Request Pull Request #2239: Remove the jest cases the browser suite already asserts

Coverage Stats

72 of 91 new or added lines in 2 files covered. (79.12%)

1 existing line in 1 file now uncovered.

6714 of 7863 relevant lines covered (85.39%)

38.05 hits per line