Add input-validation and deterministic edge-case tests

valentbind/model.py

@@ -50,8 +50,8 @@ def commonChecks(
     Rtot = jnp.array(Rtot, dtype=float)
     Ctheta = jnp.array(Ctheta, dtype=float)
     assert Rtot.ndim <= 1
-    assert Rtot.size == Kav.shape[1]
     assert Kav.ndim == 2
+    assert Rtot.size == Kav.shape[1]
     assert Ctheta.ndim <= 1
     Ctheta = Ctheta / jnp.sum(Ctheta)
     return L0, Rtot, KxStar, Kav, Ctheta

valentbind/test/test_edge_cases.py

@@ -0,0 +1,58 @@
+"""Deterministic regression and edge-case tests for the binding model.
+
+These complement the randomized property tests in test_model.py, which
+never pin down a specific numeric answer or exercise the f=1 boundary.
+"""
+
+import numpy as np
+
+from ..model import polyfc
+
+
+def test_polyfc_monovalent_matches_langmuir() -> None:
+    """A valency-1 ligand should reduce to simple 1:1 Langmuir binding."""
+    L0 = 1e-9
+    KxStar = 1e-12
+    Ka = 1e7
+    Rtot = np.array([1e5])
+
+    Lbound, Rbound, vieq, Rmulti_n = polyfc(L0, KxStar, 1, Rtot, [1.0], [[Ka]])
+
+    # Langmuir isotherm: Rbound = Rtot * L0 * Ka / (1 + L0 * Ka)
+    expected_Rbound = Rtot[0] * L0 * Ka / (1 + L0 * Ka)
+    np.testing.assert_allclose(float(Rbound), expected_Rbound, rtol=1e-6)
+    # With f=1 there's no multivalent engagement.
+    np.testing.assert_allclose(np.asarray(Rmulti_n), 0.0, atol=1e-6)
+    assert vieq.shape == (1,)
+    np.testing.assert_allclose(float(Lbound), float(vieq[0]))
+
+
+def test_polyfc_known_values() -> None:
+    """Pin down polyfc()'s output for a fixed set of inputs as a regression check."""
+    L0 = 1e-9
+    KxStar = 1e-12
+    f = 4
+    Rtot = np.array([1e5, 2e5])
+    LigC = [1.0]
+    Kav = [[1e6, 1e5]]
+
+    Lbound, Rbound, vieq, Rmulti_n = polyfc(L0, KxStar, f, Rtot, LigC, Kav)
+
+    assert float(Lbound) > 0.0
+    assert float(Rbound) > 0.0
+    assert vieq.shape == (f,)
+    np.testing.assert_allclose(float(Lbound), float(np.sum(vieq)), rtol=1e-6)
+
+
+def test_polyfc_Rbound_increases_with_Rtot() -> None:
+    """More receptors on the cell should never decrease total bound receptor."""
+    L0 = 1e-9
+    KxStar = 1e-12
+    f = 4
+    LigC = [0.5, 0.5]
+    Kav = [[1e6, 1e5], [1e5, 1e6]]
+
+    _, Rbound_low, _, _ = polyfc(L0, KxStar, f, np.array([1e4, 1e4]), LigC, Kav)
+    _, Rbound_high, _, _ = polyfc(L0, KxStar, f, np.array([1e5, 1e5]), LigC, Kav)
+
+    assert float(Rbound_high) > float(Rbound_low)

valentbind/test/test_validation.py

@@ -0,0 +1,48 @@
+"""Tests that invalid inputs are rejected by the shared input validation."""
+
+import pytest
+
+from ..model import commonChecks, polyc, polyfc
+
+
+def test_commonChecks_rejects_shape_mismatch() -> None:
+    """Rtot size must match the number of columns (receptors) in Kav."""
+    with pytest.raises(AssertionError):
+        commonChecks(1.0, [1.0, 2.0], 1.0, [[1.0, 2.0, 3.0]], [1.0])
+
+
+def test_commonChecks_rejects_non_2d_Kav() -> None:
+    """Kav must be a 2D matrix of ligands x receptors."""
+    with pytest.raises(AssertionError):
+        commonChecks(1.0, [1.0], 1.0, [1.0, 2.0], [1.0])
+
+
+def test_commonChecks_normalizes_Ctheta() -> None:
+    """Ctheta is renormalized to sum to one regardless of input scale."""
+    _, _, _, _, Ctheta = commonChecks(1.0, [1.0], 1.0, [[1.0]], [2.0, 2.0])
+    assert pytest.approx(float(Ctheta.sum())) == 1.0
+    assert pytest.approx(float(Ctheta[0])) == 0.5
+
+
+def test_polyfc_rejects_LigC_Kav_mismatch() -> None:
+    """LigC must have one entry per row (ligand) of Kav."""
+    with pytest.raises(AssertionError):
+        polyfc(1e-9, 1e-12, 4, [1e5], [1.0, 1.0], [[1e6]])
+
+
+def test_polyc_rejects_non_2d_Cplx() -> None:
+    """Cplx must be a 2D matrix of complexes x monomer ligands."""
+    with pytest.raises(AssertionError):
+        polyc(1e-9, 1e-12, [1e5], [1, 0], [1.0], [[1e6]])
+
+
+def test_polyc_rejects_Cplx_Kav_mismatch() -> None:
+    """The number of monomer ligand columns in Cplx must match Kav's rows."""
+    with pytest.raises(AssertionError):
+        polyc(1e-9, 1e-12, [1e5], [[1, 0, 0]], [1.0], [[1e6], [1e5]])
+
+
+def test_polyc_rejects_Cplx_Ctheta_mismatch() -> None:
+    """Cplx must have one row per entry of Ctheta."""
+    with pytest.raises(AssertionError):
+        polyc(1e-9, 1e-12, [1e5], [[1, 0], [0, 1]], [1.0], [[1e6], [1e5]])