074123ba2fb70164a7aa364f7c8baf21d70f55a5
braney
  Thu Aug 27 09:04:05 2026 -0700
docent: let expect: check the order rows were drawn in, refs #37892

rows: has been a set test, and exact: true only added "and nothing else",
so no assertion in the language could fail because the rows came back in
the wrong order. ordered: true adds that check: the named rows have to
appear top to bottom in the order given. A row that was not drawn at all
is reported once, by rows:, and skipped here rather than failing twice.
A failure names the first pair that is inverted.

The case that prompted it is #38032, a quickLift target returning its
tracks in the order they were lifted rather than the order they have on
the source. A tour of that bug passed every check on the broken build.

Two tests: ordered asserts the hg38 order, and ordered.xfail names the
same two rows backwards and has to fail, since a flag that cannot fail is
only a second copy of the set test beside it.

diff --git src/hg/utils/docent/tests/README.txt src/hg/utils/docent/tests/README.txt
index b7ddec1bfe5..8d0a5f71c62 100644
--- src/hg/utils/docent/tests/README.txt
+++ src/hg/utils/docent/tests/README.txt
@@ -1,86 +1,90 @@
 Docent tests
 ------------
 
 Run by hand, not by the kent tree's `make test`:
 
     make test               # every *.docent.yaml here
     make test T=composite   # just one
     make parity             # one script FAST and slow, and twice over
     make derive             # the derivation alone, against expected/ (no browser)
     make derive-accept      # rewrite those baselines, then read `git diff expected/`
 
 Most tests drive a real browser against a real server, so they need the network and
 the shared Playwright install (/hive/groups/browser/uiTest/pw; see ../README.md). That is why none of this is
 part of the tree-wide test target: a broken network would fail the build.
 
 A test is an ordinary Docent script that asserts with `expect:`. It passes by exiting
 0. `expect:` is the only verb that fails a run, so a test with no `expect:` step in it
 tests nothing.
 
 A script named *.xfail.docent.yaml is expected to FAIL, and the run fails if it passes.
 That is how a trap gets pinned rather than merely written down.
 
 `make derive` is the cheap half: DOCENT_DERIVE=1 resolves the `track:` steps against
 trackDb and prints the cart variables without opening a browser, in about a second. It
 is where Docent's own decisions live, and the baselines in expected/ are what catch a
 change to visVars() or tdbHideTargets() that a rendered page would hide.
 
 What is covered
 ---------------
 
   selftest      session: -> expect: -> loadSession:, on hg38 at SHH. Saves the cart,
                 changes the view, restores it from the local file, checks rows both times.
   composite     clinvar with clinvarCnv hidden: the two-request split (#37953). One
                 request would leave clinvarCnv_sel=1 and the CNV row drawn.
   views         hideKids on the VIEW that holds the subtrack, with the sibling views
                 hidden by name. Also covers the `_sel` checkbox, since the subtrack is
                 `parent wgEncodeRegDnaseSignal off`, and pins the superTrack side effect
                 below.
   views.xfail   the same thing aimed at the COMPOSITE instead, which loses the row.
                 Expected to fail.
   supertrack    varsInPubs hideKids + one member: `exact: true`, because a test that only
                 checked the member was present would pass with all six drawn.
   urllen        {cCREs: hideKids} must not become the 1701-variable, 42,020-character GET
                 that Apache answered with 414. Checks `noText: "Too Long"`, since a 414
                 renders as a perfectly good page; the derive baseline pins it at 3.
   customtrack   addCustomTrack: with inline BED, tabs and newlines surviving the trip.
   scale         a 3x run draws the same rows as a 1x one.
+  ordered       `ordered: true` on rows:, and the fact that a row which was not drawn is
+                reported by rows: alone rather than failing the order check as well.
+  ordered.xfail the same two rows named the wrong way round. Expected to fail -- a flag
+                that cannot fail is not a check, it is a second copy of the set test.
   expectfail    an assertion that is plainly false. Expected to fail -- if it ever passes,
     .xfail      `expect:` has stopped throwing and every other test here means nothing.
   make parity   FAST vs slow, and a rerun, on composite. FAST drops the dwells and the
                 recording and must not change what the page ends up showing; the rerun
                 catches state left behind in the cart.
 
 Two things these tests found
 ----------------------------
 
 Worth knowing before writing more:
 
   * Turning on anything under a superTrack sends `<superTrack>=show`, and every OTHER
     member then comes up at its own trackDb visibility -- so `hide: all` is undone for
     them. views asserts wgEncodeRegMarkH3k27ac comes back, rather than working around it.
     Whether Docent should be cleverer here is an open question, not a settled one.
   * `hideKids` on a VIEW has to enumerate its leaves (a view holds no sub-containers to
     stop at), so views sends 188 variables in a 6,986-character request. That is under
     Apache's 8,190 limit with less room than is comfortable. Its `noText: "Too Long"` is
     what turns a future overflow into a clear failure instead of a strange one.
 
 Still to write
 --------------
 
   mouseover:      by item: on stacked items, and the timing case where a neighbour's
                   tooltip is still up on arrival
   pinShot:        several tooltips in one figure, cursors drawn
   convert:        quickLift onto a GenArk haplotype, hideDefaults re-checked -- note a
                   session taken after it cannot be checked in, see #38046
   drag:           each of then: zoom / highlight / cancel
   addHub:,
   addPublicHub:   the two hub attach paths (a stable hub URL is the hard part)
   montage:        panel order, lettering, a named shot that was never taken
   goShow:         the suggestion menu, including a `pick:` that matches nothing
   loadSession:    the three remote forms -- only the local-file form is covered
   the YAML lint   `{item:name}` with no space warns and drops the argument. This needs a
                   test that reads stderr, which the harness does not do yet.
 
 A test that needs a stable server-side fixture (a hub, a custom track) should carry it
 in the script rather than assume something on disk.