forgetest: a path a host test proves needs no catalog test

The coverage lint failed CI on any behavioral path no catalog test
covered, so every software change pulled a new or wider acceptance test
in with it, though the catalog is for what needs the machine or an
operator. A path whose behavior a host test in CI proves now has a row
in HOST_TESTED (manifest.py): the component, a glob, the host test, and
the CI workflow that runs it, the last two as "<repository>:<path>" - a
file of a component in the manifest (its tests/ and .github/ files are
listed there), or "forgefirm:" and a path in this repository (the
null-sink harnesses, which grblhal-glowforge's workflow runs).

- coverage_report counts a host-tested path as covered. Fingerprints
  are unchanged: a path no catalog test covers is in no fingerprint,
  so a change there makes no acceptance run necessary.
- host_row_problems reports a row whose glob selects no behavioral
  file; a host test or workflow that does not exist (a component file
  missing from the manifest, a "forgefirm:" file missing from the
  checkout, the dev-only forgetest, no repository named); a workflow
  that should be readable and is not; one that does not check out the
  test's repository; and one with no step that runs the test.
- The workflow is read at the pinned revision: read_source takes a
  component's blob from the bare repo manifest-from-tree.py fetched for
  its source URL (the checkout's .manifest-cache, or --sources), a
  "forgefirm:" file from the checkout. With no sources (an image) it is
  not read and the lint says so; with sources, a read that fails is a
  problem, never a pass.
- workflow_steps reads the workflow's steps by indentation (uses, run,
  working-directory, with), comments dropped, whole lines and from
  " #"; a quoted scalar loses its quotes, a quote inside a command
  stays. checkout_path finds where the test's repository is checked out
  (its own: the checkout naming no repository; another: the checkout
  of <owner>/<name>, the name from the component's source URL).
- workflow_runs looks at what a step's run commands execute, split into
  simple commands (;, &&, ||, |, newlines, then/do/else; a backslash
  continuation joined), with sudo and its flags, env, time, exec and
  variable assignments passed over, each path resolved against the
  step's working-directory and compared with the test's workspace path:
  the command itself (a script run directly, a C test's built binary
  <dir>/<stem>); the script an interpreter runs (python, bash, sh) or a
  for loop's list, by path or a glob matching the whole path segment by
  segment; unittest discover starting in the test's own directory with
  a pattern its name matches (test*.py unless -p); pytest given the test
  or its own directory, for a name it collects. An argument to anything
  else (echo, cat, a build target), a step's name, a comment, a
  trigger's paths filter, or a path that only ends like the test's does
  not count.
- The lint prints the row problems and fails --enforce on them, as on
  an uncovered path or an empty covers entry; --json carries them as
  host_tested, with workflows_read (false when a workflow that should
  have been read was not). It reads HOST_TESTED when it runs.
- The table starts empty: rows come with the tests that leave the
  catalog.

Proof: host tests: a host-tested row takes its paths out of the report
and moves no fingerprint; good rows report nothing; each kind of bad
row is reported with its reason; a workflow that runs one harness and
names another only in its paths filter, a comment line and an inline
comment runs the first and not the second; workflow_runs on a built
binary, sudo and a binary, a script, a harness under another checkout,
pytest on a directory, a for-loop glob and unittest discover under a
step's working-directory, and not under another one; and not on a
paths entry, an inline comment, a glob or a discover that the path
only ends like (tools/tests/..., scripts/bench/tests/...), a longer
name, another file, a step's name, or a commented line in a block;
not on echo with the stem or the binary's path, a build target, cat
of a script, unittest discover from a directory above the test or
with a pattern its name misses, or pytest on a directory above it;
on discover with -p '*_test.py', pytest given the file, a script run
directly and by bash, and sudo -E with assignments continued onto the
next line; checkout_path for its own and another repository and none;
repo_name from a source URL; a component's workflow read from a bare
repo's blob, judged, not judged without the sources, and a blob that
cannot be read reported; the command line with a workflow it cannot
read reports workflows_read false and the read failure, and fails
--enforce. The manifest tests (34) pass on Windows and under Linux;
the forgetest host suite passes under Linux. Against the recipe
pins and their fetched workflows: rows for forgectrl's tray_test,
forgeext's holdkeep_test, sandbox_test (under sudo) and run_test.py
(sudo, env and assignments over three lines), the laser_stream_test
harness (grblhal-glowforge's checkout of forgefirm), gfhardware's
test_machine_lid_button (a for-loop glob under its working-directory),
gfutilities' test_frame (pytest on tests) and forgetest's own
test_manifest (unittest discover under forgefirm/forgetest) pass;
rows for forgectrl's fflog_e2e.sh, the bench script fire_test.py and
kas/source-bundle.yml (only in forgetest-ci's paths filter) are
refused. The lint on that manifest reports 0 uncovered paths and 0
host-tested row problems.

Acceptance: none. forgetest is dev-only and in no fingerprint; the
lint runs in CI, not in a campaign.

.github/workflows/forgetest-ci.yml

@@ -12,9 +12,10 @@
 #  - shared UI files: theme.css and the vendored Bootstrap the page
 #    carries are byte-identical to forgectrl's at its pinned revision
 #  - coverage lint: every source path of every component pinned by the
-#    recipes must be selected by some catalog test's coverage globs (the
-#    tree manifest is generated from the pins with git - no Yocto build);
-#    enforced: an uncovered path fails the job (https://docs.forgefirm.org/developers/acceptance/).
+#    recipes must be selected by some catalog test's coverage globs or by a
+#    host-tested row naming the host test that proves it (the tree manifest
+#    is generated from the pins with git - no Yocto build); enforced: an
+#    uncovered path fails the job (https://docs.forgefirm.org/developers/testing/).
 
 name: forgetest-ci