feat: deadline elapsed, count CLI, ids JSON

clients/deadline.py

@@ -25,6 +25,10 @@ def __init__(self, clock: MonotonicClock, timeout: float):
         self._timeout = float(timeout)
         self._started_at = clock.monotonic()
 
+    def elapsed(self) -> float:
+        """Return seconds since start; uncapped, may exceed timeout."""
+        return self._clock.monotonic() - self._started_at
+
     def remaining(self) -> float:
         """Return seconds left before the deadline (never negative)."""
         elapsed = self._clock.monotonic() - self._started_at

scenarios/cli.py

@@ -60,7 +60,15 @@ def build_parser() -> argparse.ArgumentParser:
 
     subparsers.add_parser("version", help="Print package version")
 
-    subparsers.add_parser("ids", help="Print known scenario ids")
+    ids_parser = subparsers.add_parser("ids", help="Print known scenario ids")
+    ids_parser.add_argument(
+        "--format",
+        choices=("text", "json"),
+        default="text",
+        help="Output format (default: text)",
+    )
+
+    subparsers.add_parser("count", help="Print number of known scenarios")
     return parser
 
 
@@ -153,8 +161,16 @@ def main(argv: list[str] | None = None) -> int:
         return 0
 
     if args.command == "ids":
-        for scenario_id in known_scenario_ids():
-            print(scenario_id)
+        ids = list(known_scenario_ids())
+        if args.format == "json":
+            print(json.dumps(ids, indent=2))
+        else:
+            for scenario_id in ids:
+                print(scenario_id)
+        return 0
+
+    if args.command == "count":
+        print(len(known_scenario_ids()))
         return 0
 
     return 1

tests/test_cli.py

@@ -199,7 +199,28 @@ def test_ids_prints_one_id_per_line(self):
         lines = [line for line in buffer.getvalue().splitlines() if line.strip()]
         self.assertEqual(lines, list(known_scenario_ids()))
 
+    def test_count_prints_known_scenario_count(self):
+        buffer = io.StringIO()
+        with redirect_stdout(buffer):
+            code = main(["count"])
+        self.assertEqual(code, 0)
+        self.assertEqual(buffer.getvalue().strip(), str(len(known_scenario_ids())))
 
+    def test_ids_json_format(self):
+        buffer = io.StringIO()
+        with redirect_stdout(buffer):
+            code = main(["ids", "--format", "json"])
+        self.assertEqual(code, 0)
+        parsed = json.loads(buffer.getvalue())
+        self.assertEqual(parsed, list(known_scenario_ids()))
+
+    def test_ids_text_format_default_unchanged(self):
+        buffer = io.StringIO()
+        with redirect_stdout(buffer):
+            code = main(["ids", "--format", "text"])
+        self.assertEqual(code, 0)
+        lines = [line for line in buffer.getvalue().splitlines() if line.strip()]
+        self.assertEqual(lines, list(known_scenario_ids()))
 
 
 if __name__ == "__main__":

tests/test_deadline.py

@@ -41,6 +41,16 @@ def test_negative_timeout_rejected(self):
         with self.assertRaises(ValueError):
             Deadline(clock, timeout=-1.0)
 
+    def test_elapsed_tracks_fake_clock_uncapped(self):
+        clock = FakeClock()
+        deadline = Deadline(clock, timeout=0.5)
+        self.assertAlmostEqual(deadline.elapsed(), 0.0)
+        clock.sleep(0.4)
+        self.assertAlmostEqual(deadline.elapsed(), 0.4)
+        clock.sleep(0.4)
+        self.assertAlmostEqual(deadline.elapsed(), 0.8)
+        self.assertGreater(deadline.elapsed(), 0.5)
+
 
 if __name__ == "__main__":
     unittest.main()