CI: Add metadata.toml validation workflow (implements #3272)

.github/workflows/scripts/validate_metadata.py

@@ -0,0 +1,68 @@
+"""Validate metadata.toml files in all examples."""
+
+import sys
+from pathlib import Path
+
+import tomllib
+
+REQUIRED_FIELDS = [
+    "title",
+    "abstract",
+    "authors",
+    "domain",
+    "space",
+    "time",
+    "complexity",
+    "keywords",
+    "mesa",
+]
+
+ALLOWED_SPACE = {"Grid", "Network", "Continuous", "None"}
+ALLOWED_TIME = {"Discrete", "Continuous"}
+ALLOWED_COMPLEXITY = {"Basic", "Advanced"}
+
+errors = []
+examples_dir = Path("examples")
+
+metadata_files = list(examples_dir.glob("*/metadata.toml"))
+
+if not metadata_files:
+    print("No metadata.toml files found.")
+    sys.exit(0)
+
+for path in metadata_files:
+    example = path.parent.name
+    with open(path, "rb") as f:
+        try:
+            data = tomllib.load(f)
+        except tomllib.TOMLDecodeError as e:
+            errors.append(f"{example}: Invalid TOML - {e}")
+            continue
+
+    for field in REQUIRED_FIELDS:
+        if field not in data:
+            errors.append(f"{example}: Missing required field '{field}'")
+
+    if "space" in data and data["space"] not in ALLOWED_SPACE:
+        errors.append(
+            f"{example}: 'space' must be one of {ALLOWED_SPACE}, got '{data['space']}'"
+        )
+
+    if "time" in data and data["time"] not in ALLOWED_TIME:
+        errors.append(
+            f"{example}: 'time' must be one of {ALLOWED_TIME}, got '{data['time']}'"
+        )
+
+    if "complexity" in data and data["complexity"] not in ALLOWED_COMPLEXITY:
+        errors.append(
+            f"{example}: 'complexity' must be one of {ALLOWED_COMPLEXITY}, "
+            f"got '{data['complexity']}'"
+        )
+
+if errors:
+    print("Metadata validation FAILED:")
+    for e in errors:
+        print(f"  - {e}")
+    sys.exit(1)
+
+print(f"All {len(metadata_files)} metadata.toml files are valid.")

.github/workflows/validate_metadata.yml

@@ -0,0 +1,24 @@
+name: Validate Example Metadata
+
+on:
+  pull_request:
+    paths:
+      - 'examples/**/metadata.toml'
+      - '.github/workflows/validate_metadata.yml'
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install tomllib (stdlib in 3.11+)
+        run: echo "tomllib is built-in"
+
+      - name: Validate all metadata.toml files
+        run: python scripts/validate_metadata.py

examples/deffuant_weisbuch/deffuant_weisbuch/model.py

@@ -58,7 +58,8 @@ def step(self):
         less than the confidence threshold, both agents update opinion values
         symmetrically.
         """
-        agent_list = self.agents.to_list()
+        agent_list = list(self.agents)
+        # this is fix by vanya
         for _ in range(self.n):
             agent_a, agent_b = self.random.sample(agent_list, 2)
             self.attempted_interactions += 1

examples/forest_fire/forest_fire/metadata.toml

@@ -0,0 +1,23 @@
+title = "Forest Fire Model"
+
+abstract = """
+A simple cellular automaton model of fire spreading through a forest.
+Trees grow randomly, and fire spreads to neighboring trees. Demonstrates
+self-organized criticality and emergent behavior from simple local rules.
+"""
+
+authors = ["Wilensky, U."]
+
+domain = ["ecology", "complex systems"]
+
+space = "Grid"
+
+time = "Discrete"
+
+complexity = "Basic"
+
+keywords = ["forest fire", "cellular automaton", "self-organized criticality", "fire spread"]
+
+mesa = ">=3.0"
+
+doi = ""