The owed Muse reads of #632 and #639: three boundary cases and their mutants

tests/test_decide.py

@@ -1860,6 +1860,9 @@ def test_an_approval_is_anchored_at_the_act_that_read_the_description(self):  #
         self.assertEqual(d["reason"], "description_edited_after_approval")
         # A re-run whose dispatch was not read may be the act that read, made before it: nothing shows when, so it holds.
         unread = dict(act, started_at="2026-10-11T12:30:00Z", rerun_by_dispatcher=False)
+        # The records are always given: with none, the anchor would be the approval's own time, which issue 608 ended.
+        with self.assertRaisesRegex(TypeError, "runs"):
+            derive.description_anchor(facts(reviews=[approval]), "2026-10-11T12:10:00Z")
         self.assertEqual(derive.description_anchor(facts(reviews=[approval]), "2026-10-11T12:10:00Z", runs=REVIEWED + [unread]), "")
         d = go(facts(reviews=[approval], description_edited_at="2026-10-11T12:10:00Z"), REVIEWED + [unread])
         self.assertEqual(d["reason"], "description_edited_after_approval")

tests/test_evals.py

@@ -2586,6 +2586,13 @@ def __call__(self, args, env, timeout, **given):
         self.clean()
         (self.temp / "heldout").mkdir()
         self.assertEqual(self.step(plan), "scratch_unreadable")
+        # The plan places the heads by heads_place: a heads folder linked to a place in the workspace that is not there
+        # yet stops it before it makes anything there (the Muse read of issue 626's change).
+        self.clean()
+        os.symlink(str(self.work / "evil"), str(self.temp / "heads"))
+        self.assertEqual(self.step(plan), "scratch_in_workspace")
+        self.assertFalse(os.path.lexists(str(self.work / "evil")), "nothing is made in the workspace")
+        os.unlink(str(self.temp / "heads"))
 
     def test_each_cases_head_is_read_with_no_credential_and_one_not_read_closes_the_gate(self):  # decision 0138
         # The fetch reads each case's head, the commit its diff was taken at, as its tarball through a transport of its

tests/test_simulator.py

@@ -562,6 +562,8 @@ def run(at, intent=terms.ISSUE_APPROVAL, content="sha256:00c1"):
                 ([run(10), run(13, intent="review-change")], 12, True),
                 ([run(10), run(13, content="sha256:00c2")], 12, True),
                 ([run(5, intent="review-change")], 10, False),
+                # A Run of the item in the approval's own second is as old as it (the Muse read of issue 608's change).
+                ([run(15, intent="review-change")], 10, False),
                 ([], 10, True),
                 ([run(16)], 10, True)):
             self.assertEqual(self.read([review(machine, 15)], edited, runs), (held, held), (runs, edited))

tools/mutants.py

@@ -15633,6 +15633,17 @@ def moved_before(rel: str, block: str, anchor: str) -> tuple:
     ("the world dates each approval by its own time still", 'sim/world.py',
      '        anchor = min(self.read_at(rv) for rv in since) if since else (look if machine else None)\n',
      '        anchor = min(rv["submitted_at"] for rv in since) if since else (look if machine else None)\n', ('tests.test_simulator.Simulation.test_the_worlds_reading_of_an_edit_after_the_approval_is_the_kernels',)),
+    # The owed Muse reads of issues 608 and 626's changes: a Run in the approval's own second, the records always given,
+    # and the plan's heads placed by heads_place.
+    ("the world takes a Run in the approval's own second as after it", 'sim/world.py',
+     '        return at if any(r["started_at"] <= at for r in self.runs) else ""\n', '        return at if any(r["started_at"] < at for r in self.runs) else ""\n',
+     ('tests.test_simulator.Simulation.test_the_worlds_reading_of_an_edit_after_the_approval_is_the_kernels',)),
+    ("the description's anchor takes no records by default", 'kernel/derive.py',
+     'def description_anchor(facts: dict, edited: str, *, runs: list):', 'def description_anchor(facts: dict, edited: str, *, runs: list = ()):',
+     ('tests.test_decide.Convergence.test_an_approval_is_anchored_at_the_act_that_read_the_description',)),
+    ('the plan places the heads by their path alone', 'harness/eval/__init__.py',
+     '    place, heads = scratch(env, workspace), heads_place(env, workspace)\n', '    place, heads = scratch(env, workspace), pathlib.Path(os.path.realpath(os.path.join(env["RUNNER_TEMP"], "heads")))\n',
+     APART),
     ('the calls go unread', 'tools/check_purity.py',
      '        problems += _calls(name, tree, trees, takers, tops)\n',
      '', ('tests.test_tools.Purity.test_the_kernel_calls_nothing_it_is_given', 'tests.test_tools.Purity.test_what_fills_a_decision_maker_is_a_kernel_function')),