test: add argv-safe dogfood probes

tests/test_roadmap_helpers.py

@@ -9,6 +9,9 @@ from pathlib import Path
 
 REPO_ROOT = Path(__file__).resolve().parents[1]
 NEXT_ID = REPO_ROOT / 'scripts' / 'roadmap-next-id.sh'
+DOGFOOD_PROBE = REPO_ROOT / 'scripts' / 'dogfood-probe.py'
+
+
 
 
 def run_next_id(roadmap: Path, script: Path = NEXT_ID) -> subprocess.CompletedProcess[str]:
@@ -21,6 +24,16 @@ def run_next_id(roadmap: Path, script: Path = NEXT_ID) -> subprocess.CompletedPr
     )
 
 
+def run_dogfood_probe(args: list[str]) -> subprocess.CompletedProcess[str]:
+    return subprocess.run(
+        ['python3', str(DOGFOOD_PROBE), *args],
+        cwd=REPO_ROOT,
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+
+
 class RoadmapHelperTests(unittest.TestCase):
     def test_roadmap_next_id_prints_only_next_id_after_duplicate_check(self) -> None:
         with tempfile.TemporaryDirectory() as temp_dir:
@@ -62,6 +75,78 @@ class RoadmapHelperTests(unittest.TestCase):
         self.assertIn('required ROADMAP id checker not found or not readable', result.stderr)
         self.assertIn('refusing to print a next id', result.stderr)
 
+    def test_dogfood_probe_runs_explicit_argv_and_separates_channels(self) -> None:
+        with tempfile.TemporaryDirectory() as temp_dir:
+            fixture = Path(temp_dir) / 'fixture.py'
+            fixture.write_text(
+                'from __future__ import annotations\n'
+                'import json\n'
+                'import sys\n'
+                'print(json.dumps({"argv": sys.argv[1:]}))\n'
+                'print("diagnostic", file=sys.stderr)\n'
+            )
+
+            result = run_dogfood_probe([
+                '--stdout-json-byte0',
+                '--',
+                'python3',
+                str(fixture),
+                '--output-format',
+                'json',
+                'doctor',
+                '--help',
+            ])
+
+        self.assertEqual(0, result.returncode)
+        payload = __import__('json').loads(result.stdout)
+        self.assertEqual('ok', payload['kind'])
+        self.assertEqual([
+            'python3',
+            str(fixture),
+            '--output-format',
+            'json',
+            'doctor',
+            '--help',
+        ], payload['argv'])
+        self.assertEqual(0, payload['returncode'])
+        self.assertEqual('{"argv": ["--output-format", "json", "doctor", "--help"]}\n', payload['stdout'])
+        self.assertEqual('diagnostic\n', payload['stderr'])
+
+    def test_dogfood_probe_labels_timeout_separately_from_product_error(self) -> None:
+        with tempfile.TemporaryDirectory() as temp_dir:
+            fixture = Path(temp_dir) / 'sleep.py'
+            fixture.write_text('import time\ntime.sleep(2)\n')
+
+            result = run_dogfood_probe(['--timeout', '0.1', '--', 'python3', str(fixture)])
+
+        self.assertEqual(1, result.returncode)
+        payload = __import__('json').loads(result.stdout)
+        self.assertEqual('timeout', payload['kind'])
+        self.assertIsNone(payload['returncode'])
+        self.assertIn('timed out', payload['message'])
+
+    def test_dogfood_probe_labels_probe_construction_failure(self) -> None:
+        result = run_dogfood_probe([])
+
+        self.assertEqual(1, result.returncode)
+        payload = __import__('json').loads(result.stdout)
+        self.assertEqual('probe_error', payload['kind'])
+        self.assertEqual([], payload['argv'])
+        self.assertIsNone(payload['returncode'])
+        self.assertIn('argv must contain', payload['message'])
+
+    def test_dogfood_probe_labels_stdout_json_prefix_failure_as_product_error(self) -> None:
+        with tempfile.TemporaryDirectory() as temp_dir:
+            fixture = Path(temp_dir) / 'prefixed.py'
+            fixture.write_text('print("warning before json")\nprint("{}")\n')
+
+            result = run_dogfood_probe(['--stdout-json-byte0', '--', 'python3', str(fixture)])
+
+        self.assertEqual(1, result.returncode)
+        payload = __import__('json').loads(result.stdout)
+        self.assertEqual('product_error', payload['kind'])
+        self.assertEqual(0, payload['returncode'])
+        self.assertIn('byte 0', payload['message'])
 
 if __name__ == '__main__':
     unittest.main()