Explicitly test basic examples (#2390)

mesa/examples/basic/boltzmann_wealth_model/model.py

@@ -11,8 +11,8 @@ class BoltzmannWealthModel(mesa.Model):
     highly skewed distribution of wealth.
     """
 
-    def __init__(self, n=100, width=10, height=10):
-        super().__init__()
+    def __init__(self, n=100, width=10, height=10, seed=None):
+        super().__init__(seed=seed)
         self.num_agents = n
         self.grid = mesa.space.MultiGrid(width, height, True)
 

mesa/examples/basic/conways_game_of_life/model.py

@@ -7,9 +7,9 @@
 class ConwaysGameOfLife(Model):
     """Represents the 2-dimensional array of cells in Conway's Game of Life."""
 
-    def __init__(self, width=50, height=50):
+    def __init__(self, width=50, height=50, seed=None):
         """Create a new playing area of (width, height) cells."""
-        super().__init__()
+        super().__init__(seed=seed)
         # Use a simple grid, where edges wrap around.
         self.grid = SingleGrid(width, height, torus=True)
 

mesa/examples/basic/virus_on_network/model.py

@@ -36,8 +36,9 @@ def __init__(
         virus_check_frequency=0.4,
         recovery_chance=0.3,
         gain_resistance_chance=0.5,
+        seed=None,
     ):
-        super().__init__()
+        super().__init__(seed=seed)
         self.num_nodes = num_nodes
         prob = avg_node_degree / self.num_nodes
         self.G = nx.erdos_renyi_graph(n=self.num_nodes, p=prob)
@@ -56,6 +57,7 @@ def __init__(
                 "Infected": number_infected,
                 "Susceptible": number_susceptible,
                 "Resistant": number_resistant,
+                "R over S": self.resistant_susceptible_ratio,
             }
         )
 
@@ -93,7 +95,3 @@ def step(self):
         self.agents.shuffle_do("step")
         # collect data
         self.datacollector.collect(self)
-
-    def run_model(self, n):
-        for _ in range(n):
-            self.step()

tests/test_examples.py

@@ -1,90 +1,40 @@
 # noqa: D100
-import contextlib
-import importlib
-import os.path
-import sys
-import unittest
+from mesa.examples import (
+    BoidFlockers,
+    BoltzmannWealthModel,
+    ConwaysGameOfLife,
+    Schelling,
+    VirusOnNetwork,
+)
 
 
-def test_examples_imports():
-    """Test examples imports."""
-    from mesa.examples import (
-        BoidFlockers,
-        BoltzmannWealthModel,
-        ConwaysGameOfLife,
-        Schelling,
-        VirusOnNetwork,
-    )
+def test_boltzmann_model():  # noqa: D103
+    model = BoltzmannWealthModel(seed=42)
 
-    BoltzmannWealthModel()
-    Schelling()
-    BoidFlockers()
-    ConwaysGameOfLife()
-    VirusOnNetwork()
+    for _i in range(10):
+        model.step()
 
 
-def classcase(name):  # noqa: D103
-    return "".join(x.capitalize() for x in name.replace("-", "_").split("_"))
+def test_conways_game_model():  # noqa: D103
+    model = ConwaysGameOfLife(seed=42)
+    for _i in range(10):
+        model.step()
 
 
-@unittest.skip(
-    "Skipping TextExamples, because examples folder was moved. More discussion needed."
-)
-class TestExamples(unittest.TestCase):
-    """Test examples' models.
+def test_schelling_model():  # noqa: D103
+    model = Schelling(seed=42)
+    for _i in range(10):
+        model.step()
 
-    This creates a model object and iterates it through
-    some steps.  The idea is to get code coverage, rather than to test the
-    details of each example's model.
-    """
 
-    EXAMPLES = os.path.abspath(
-        os.path.join(os.path.dirname(__file__), "../mesa/examples")
-    )
+def test_virus_on_network():  # noqa: D103
+    model = VirusOnNetwork(seed=42)
+    for _i in range(10):
+        model.step()
 
-    @contextlib.contextmanager
-    def active_example_dir(self, example):
-        """Save and restore sys.path and sys.modules."""
-        old_sys_path = sys.path[:]
-        old_sys_modules = sys.modules.copy()
-        old_cwd = os.getcwd()
-        example_path = os.path.abspath(os.path.join(self.EXAMPLES, example))
-        try:
-            sys.path.insert(0, example_path)
-            os.chdir(example_path)
-            yield
-        finally:
-            os.chdir(old_cwd)
-            added = [m for m in sys.modules if m not in old_sys_modules]
-            for mod in added:
-                del sys.modules[mod]
-            sys.modules.update(old_sys_modules)
-            sys.path[:] = old_sys_path
 
-    def test_examples(self):  # noqa: D102
-        for example in os.listdir(self.EXAMPLES):
-            if not os.path.isdir(os.path.join(self.EXAMPLES, example)):
-                continue
-            if hasattr(self, f"test_{example.replace('-', '_')}"):
-                # non-standard example; tested below
-                continue
+def test_boid_flockers():  # noqa: D103
+    model = BoidFlockers(seed=42)
 
-            print(f"testing example {example!r}")
-            with self.active_example_dir(example):
-                try:
-                    # epstein_civil_violence.py at the top level
-                    mod = importlib.import_module("model")
-                    server = importlib.import_module("server")
-                    server.server.render_model()
-                except ImportError:
-                    # <example>/epstein_civil_violence.py
-                    mod = importlib.import_module(f"{example.replace('-', '_')}.model")
-                    server = importlib.import_module(
-                        f"{example.replace('-', '_')}.server"
-                    )
-                    server.server.render_model()
-                model_class = getattr(mod, classcase(example))
-                model = model_class()
-                for _ in range(10):
-                    model.step()
-                self.assertEqual(model.steps, 10)
+    for _i in range(10):
+        model.step()