fix: unnecessary modification (#1695)

src/ape/api/projects.py

@@ -137,19 +137,22 @@ def cached_manifest(self) -> Optional[PackageManifest]:
 
     @property
     def contracts(self) -> Dict[str, ContractType]:
-        if self._contracts is None:
-            contracts = {}
-            for p in self._cache_folder.glob("*.json"):
-                if p == self.manifest_cachefile:
-                    continue
+        if self._contracts is not None:
+            return self._contracts
+
+        contracts = {}
+        for p in self._cache_folder.glob("*.json"):
+            if p == self.manifest_cachefile:
+                continue
+
+            contract_name = p.stem
+            contract_type = ContractType.parse_file(p)
+            if contract_type.name is None:
+                contract_type.name = contract_name
 
-                contract_name = p.stem
-                contract_type = ContractType.parse_file(p)
-                if contract_type.name is None:
-                    contract_type.name = contract_name
+            contracts[contract_type.name] = contract_type
 
-                contracts[contract_type.name] = contract_type
-            self._contracts = contracts
+        self._contracts = contracts
         return self._contracts
 
     @property

src/ape/managers/project/manager.py

@@ -407,7 +407,7 @@ def contracts(self) -> Dict[str, ContractType]:
         Returns:
             Dict[str, ``ContractType``]
         """
-        if self.local_project._cached_manifest is None:
+        if self.local_project.cached_manifest is None:
             return self.load_contracts()
 
         return self.local_project.contracts

tests/functional/test_project.py

@@ -1,3 +1,4 @@
+import os
 import shutil
 from pathlib import Path
 from urllib.parse import urlparse
@@ -394,3 +395,21 @@ def test_getattr_contract_not_exists(project):
     contract.touch()
     with pytest.raises(AttributeError, match=expected):
         _ = project.ThisIsNotAContractThatExists
+
+
+def test_build_file_only_modified_once(project_with_contract):
+    project = project_with_contract
+    artifact = project.path / ".build" / "__local__.json"
+    _ = project.contracts  # Ensure compiled.
+
+    # NOTE: This is how re-create the bug. Delete the underscore-prefixed
+    #  cached object and attempt to re-compile. Previously, the ProjectManager
+    #  was relying on an internal cache rather than the external one, and thus
+    #  caused the file to get unnecessarily re-made (modified).
+    project.local_project._cached_manifest = None
+
+    # Prove the file is not unnecessarily modified.
+    time_before = os.path.getmtime(artifact)
+    _ = project.contracts
+    time_after = os.path.getmtime(artifact)
+    assert time_before == time_after