Silently check today's NYT Wordle answer on startup

Queries the NYT wordle/v2 endpoint once per calendar day (cached via
~/.wordle_solver/state.json) and adds the word via the existing
/addword mechanism if it's missing from answers.txt. Fully silent in
every outcome; --no-nyt-check / --force-nyt-check control it from the
CLI.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ert8f6E6yzmWg5qbcFPDLP

tests/test_nyt_check.py

@@ -0,0 +1,123 @@
+import json
+from datetime import date
+from unittest.mock import patch
+
+from wordle_solver.nyt_check import fetch_todays_answer, maybe_check_nyt_word
+from wordle_solver.solver import Solver
+
+
+def _write_lists(data_dir, answers, guesses):
+    (data_dir / "answers.txt").write_text("\n".join(answers) + "\n")
+    (data_dir / "guesses.txt").write_text("\n".join(guesses) + "\n")
+
+
+def _mock_response(body: dict):
+    class _Resp:
+        def __enter__(self):
+            return self
+
+        def __exit__(self, *a):
+            return False
+
+        def read(self):
+            return json.dumps(body).encode()
+
+    return _Resp()
+
+
+class TestFetchTodaysAnswer:
+    def test_returns_solution_on_success(self):
+        with patch("wordle_solver.nyt_check.urllib.request.urlopen",
+                   return_value=_mock_response({"solution": "CRANE"})):
+            assert fetch_todays_answer() == "crane"
+
+    def test_returns_none_on_network_error(self):
+        with patch("wordle_solver.nyt_check.urllib.request.urlopen", side_effect=OSError("boom")):
+            assert fetch_todays_answer() is None
+
+    def test_returns_none_on_malformed_body(self):
+        with patch("wordle_solver.nyt_check.urllib.request.urlopen",
+                   return_value=_mock_response({"solution": "notfive"})):
+            assert fetch_todays_answer() is None
+
+
+class TestMaybeCheckNytWord:
+    def test_skip_flag_short_circuits(self, tmp_path):
+        solver = Solver(["crane"], ["trace"])
+        with patch("wordle_solver.nyt_check.fetch_todays_answer") as fetch:
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=tmp_path / "state.json",
+                                           skip=True)
+        assert result is None
+        fetch.assert_not_called()
+
+    def test_cache_hit_skips_fetch(self, tmp_path):
+        _write_lists(tmp_path, ["crane"], ["trace"])
+        state_path = tmp_path / "state.json"
+        state_path.write_text(json.dumps({"last_checked": date.today().isoformat()}))
+        solver = Solver(["crane"], ["trace"])
+
+        with patch("wordle_solver.nyt_check.fetch_todays_answer") as fetch:
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=state_path)
+
+        assert result is None
+        fetch.assert_not_called()
+
+    def test_adds_missing_word_and_updates_state(self, tmp_path):
+        _write_lists(tmp_path, ["crane"], ["zesty"])
+        state_path = tmp_path / "state.json"
+        solver = Solver(["crane"], ["zesty"])
+
+        with patch("wordle_solver.nyt_check.fetch_todays_answer", return_value="zesty"):
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=state_path)
+
+        assert result == "zesty"
+        assert "zesty" in solver.answers
+        assert "zesty" not in solver.extra_guesses
+        assert "zesty" in solver.candidates
+        assert (tmp_path / "answers.txt").read_text().splitlines() == ["crane", "zesty"]
+        assert json.loads(state_path.read_text())["last_checked"]
+
+    def test_already_known_word_is_noop_but_updates_state(self, tmp_path):
+        _write_lists(tmp_path, ["crane"], [])
+        state_path = tmp_path / "state.json"
+        solver = Solver(["crane"], [])
+
+        with patch("wordle_solver.nyt_check.fetch_todays_answer", return_value="crane"):
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=state_path)
+
+        assert result is None
+        assert json.loads(state_path.read_text())["last_checked"]
+
+    def test_network_failure_does_not_update_state(self, tmp_path):
+        _write_lists(tmp_path, ["crane"], [])
+        state_path = tmp_path / "state.json"
+        solver = Solver(["crane"], [])
+
+        with patch("wordle_solver.nyt_check.fetch_todays_answer", return_value=None):
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=state_path)
+
+        assert result is None
+        assert not state_path.exists()
+
+    def test_force_bypasses_cache(self, tmp_path):
+        _write_lists(tmp_path, ["crane"], ["zesty"])
+        state_path = tmp_path / "state.json"
+        state_path.write_text(json.dumps({"last_checked": date.today().isoformat()}))
+        solver = Solver(["crane"], ["zesty"])
+
+        with patch("wordle_solver.nyt_check.fetch_todays_answer", return_value="zesty") as fetch:
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=state_path, force=True)
+
+        fetch.assert_called_once()
+        assert result == "zesty"
+
+    def test_corrupt_state_file_treated_as_empty(self, tmp_path):
+        _write_lists(tmp_path, ["crane"], [])
+        state_path = tmp_path / "state.json"
+        state_path.write_text("not json")
+        solver = Solver(["crane"], [])
+
+        with patch("wordle_solver.nyt_check.fetch_todays_answer", return_value=None):
+            result = maybe_check_nyt_word(solver, data_dir=tmp_path, state_path=state_path)
+
+        assert result is None