From 378a3b16760adaeabea30c1e648b272056d2494e Mon Sep 17 00:00:00 2001
From: Davide Grilli <davide.grilli@outlook.com>
Date: Wed, 13 May 2026 22:01:48 +0200
Subject: [PATCH] aggiunta suite di test fisici per fdm/solver.py

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 tests/__init__.py        |  0
 tests/test_fdm_solver.py | 70 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 tests/__init__.py
 create mode 100644 tests/test_fdm_solver.py

diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_fdm_solver.py b/tests/test_fdm_solver.py
new file mode 100644
index 0000000..a8a0cbf
--- /dev/null
+++ b/tests/test_fdm_solver.py
@@ -0,0 +1,70 @@
+import numpy as np
+import pytest
+import sys, os
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import config
+
+
+def run_solver_with(x_src):
+    """Run solver with a temporary X_SRC override."""
+    original = config.X_SRC
+    config.X_SRC = x_src
+    try:
+        from fdm import solver
+        import importlib
+        importlib.reload(solver)
+        return solver.solve()
+    finally:
+        config.X_SRC = original
+
+
+def test_shape():
+    """Output deve avere forma (NX, NT)."""
+    T, x, t = run_solver_with(0.0)
+    assert T.shape == (config.NX, config.NT)
+    assert len(x) == config.NX
+    assert len(t) == config.NT
+
+
+def test_initial_condition():
+    """La prima colonna deve essere uniforme a T0."""
+    T, x, t = run_solver_with(0.0)
+    np.testing.assert_allclose(T[:, 0], config.T0)
+
+
+def test_temperature_increases_near_source_center():
+    """Con x_src=0.5 e a fine simulazione, il nodo centrale
+    deve essere più caldo di quello iniziale."""
+    T, x, t = run_solver_with(0.5)
+    i_src = int(np.argmin(np.abs(x - 0.5)))
+    assert T[i_src, -1] > config.T0
+
+
+def test_temperature_increases_near_source_left():
+    """Con x_src=0.0 il nodo sinistro deve scaldarsi."""
+    T, x, t = run_solver_with(0.0)
+    assert T[0, -1] > config.T0
+
+
+def test_temperature_increases_near_source_right():
+    """Con x_src=L il nodo destro deve scaldarsi."""
+    T, x, t = run_solver_with(config.L)
+    assert T[-1, -1] > config.T0
+
+
+def test_x_src_position_affects_profile():
+    """Spostandosi la sorgente da 0.1 a 0.9, il massimo del profilo
+    finale deve spostarsi verso destra."""
+    T_left, x, _ = run_solver_with(0.1)
+    T_right, _, _ = run_solver_with(0.9)
+    x_max_left = x[np.argmax(T_left[:, -1])]
+    x_max_right = x[np.argmax(T_right[:, -1])]
+    assert x_max_right > x_max_left
+
+
+def test_no_nan_or_inf():
+    """La soluzione non deve contenere NaN o Inf."""
+    for x_src in [0.0, 0.25, 0.5, 0.75, 1.0]:
+        T, _, _ = run_solver_with(x_src)
+        assert np.all(np.isfinite(T)), f"NaN/Inf con x_src={x_src}"