release: v0.8.6

python/tests/test_doc_api_contract.py

@@ -0,0 +1,60 @@
+"""Doc <-> code signature contract.
+
+These assertions encode the public signatures and helper outputs that the
+online documentation and the interactive notebook rely on. They are cheap,
+IO-free, and Pro-free, and exist to catch *doc drift*: if a documented kwarg,
+preset, or helper shape changes in the code, a doc snippet silently breaks.
+
+This guards, among others:
+  * ``plot.monte_carlo`` exposing ``n_simulations`` (NOT ``n_paths``) -- the
+    notebook bug where ``n_paths=`` raised TypeError.
+  * ``Slippage.volume_impact`` emitting ``impact_coeff``/``exponent`` -- the
+    notebook bug where ``{"coefficient": ...}`` failed Rust deserialization.
+  * ``DataStore`` accepting ``mega``/``arrow_dir`` -- the doc signature that
+    omitted them.
+"""
+import inspect
+
+import manifoldbt as bt
+
+
+def test_monte_carlo_uses_n_simulations_not_n_paths():
+    params = inspect.signature(bt.plot.monte_carlo).parameters
+    assert "n_simulations" in params
+    assert "n_paths" not in params  # the notebook snippet bug
+
+
+def test_slippage_helper_shapes_match_serde():
+    # Keys must match the Rust SlippageConfig serde variants exactly.
+    assert bt.Slippage.volume_impact(0.1) == {
+        "VolumeImpact": {"impact_coeff": 0.1, "exponent": 1.5}
+    }
+    assert bt.Slippage.fixed_bps(2.0) == {"FixedBps": {"bps": 2.0}}
+
+
+def test_interval_helper_shapes():
+    assert bt.Interval.seconds(1) == {"Seconds": 1}
+    assert bt.Interval.minutes(1) == {"Minutes": 1}
+    assert bt.Interval.hours(12) == {"Hours": 12}
+    assert bt.Interval.days(1) == {"Days": 1}
+
+
+def test_fee_presets_match_documented_values():
+    # Documented under #configuration > FeeConfig Presets.
+    perps = bt.FeeConfig.binance_perps()
+    assert (perps.maker_fee_bps, perps.taker_fee_bps) == (2.0, 5.0)
+    spot = bt.FeeConfig.binance_spot()
+    assert (spot.maker_fee_bps, spot.taker_fee_bps) == (10.0, 10.0)
+
+
+def test_datastore_accepts_mega_and_arrow_dir_kwargs(tmp_path):
+    # The real signature is (data_root, metadata_db, dataset, mega, arrow_dir).
+    # We only assert the kwargs are *accepted* (no TypeError for unknown kwarg);
+    # any runtime/IO error from opening an empty dir is fine for this contract.
+    for kw in ("mega", "arrow_dir"):
+        try:
+            bt.DataStore(str(tmp_path), dataset="bars_1m", **{kw: str(tmp_path)})
+        except TypeError as exc:  # unexpected keyword argument -> contract broken
+            raise AssertionError(f"DataStore rejected kwarg {kw!r}: {exc}")
+        except Exception:
+            pass  # non-TypeError (e.g. cannot open store) -> kwarg was accepted