Check of cycles in configuration files.

Author: gupichon-soleil

pyaml/configuration/fileloader.py

@@ -15,43 +15,49 @@
 
 logger = logging.getLogger(__name__)
 
-#TODO
-#Implement cycle detection in case of wrong yaml/json link that creates a cycle
+accepted_suffixes = [".yaml", ".yml", ".json"]
 
-def load(filename:str) -> Union[dict,list]:
+def load(filename:str, paths_stack:list=None) -> Union[dict,list]:
     """Load recursively a configuration setup"""
     if filename.endswith(".yaml") or filename.endswith(".yml"):
-        l = YAMLLoader(filename)
+        l = YAMLLoader(filename, paths_stack)
     elif filename.endswith(".json"):
-        l = JSONLoader(filename)
+        l = JSONLoader(filename, paths_stack)
     else:
         raise PyAMLException(f"{filename} File format not supported (only .yaml .yml or .json)")
-    return l.load(filename)
+    return l.load()
+
+# Expand condition
+def hasToExpand(value):
+    return isinstance(value,str) and any(value.endswith(suffix) for suffix in accepted_suffixes)
+
 
 # Loader base class (nested files expansion)
 class Loader:
 
-    def __init__(self, filename:str):
-        self.suffixes = []
+    def __init__(self, filename:str, parent_path_stack:list):
         self.path:Path = get_root_folder() / filename
+        self.files_stack = []
+        if parent_path_stack:
+            if any(self.path.samefile(parent_path) for parent_path in parent_path_stack):
+                raise PyAMLException(f"A cycle has been detected: {parent_path_stack}")
+            self.files_stack.extend(parent_path_stack)
+        self.files_stack.append(self.path)
 
-    # Expand condition
-    def hasToExpand(self,value):
-        return isinstance(value,str) and any(value.endswith(suffix) for suffix in self.suffixes)
 
     # Recursively expand a dict
     def expand_dict(self,d:dict):
         for key, value in d.items():
-            if self.hasToExpand(value):
-                d[key] = load(value)
+            if hasToExpand(value):
+                d[key] = load(value, self.files_stack)
             else:
                 self.expand(value)
 
     # Recursively expand a list
     def expand_list(self,l:list):
         for idx,value in enumerate(l):
-            if self.hasToExpand(value):
-                l[idx] = load(value)
+            if hasToExpand(value):
+                l[idx] = load(value, self.files_stack)
             else:
                 self.expand(value)
 
@@ -65,7 +71,7 @@ def expand(self,obj: Union[dict,list]):
 
     # Load a file
     def load(self) -> Union[dict,list]:
-        raise Exception(str(self.path) + ": load() method not implemented")
+        raise PyAMLException(str(self.path) + ": load() method not implemented")
 
 class SafeLineLoader(SafeLoader):
 
@@ -93,22 +99,24 @@ def construct_mapping(self, node, deep=False):
 
 # YAML loader
 class YAMLLoader(Loader):
-    
-    def load(self,fileName:str) -> Union[dict,list]:
-        self.path:Path = get_root_folder() / fileName
-        self.suffixes = [".yaml",".yml"]
+    def __init__(self, filename: str, parent_paths_stack:list):
+        super().__init__(filename, parent_paths_stack)
+
+    def load(self) -> Union[dict,list]:
+        logger.log(logging.DEBUG, f"Loading YAML file '{self.path}'")
         with open(self.path) as file:
             try:
                 return self.expand(yaml.load(file,Loader=SafeLineLoader))
             except yaml.YAMLError as e:
-                raise Exception(self.path + ": " + str(e))
+                raise PyAMLException(str(self.path) + ": " + str(e)) from e
 
 # JSON loader
 class JSONLoader(Loader):
+    def __init__(self, filename: str, parent_paths_stack:list):
+        super().__init__(filename, parent_paths_stack)
 
-    def  load(self,fileName:str) -> Union[dict,list]:
+    def  load(self) -> Union[dict,list]:
         logger.log(logging.DEBUG, f"Loading JSON file '{self.path}'")
-        self.suffixes = [".json"]
         with open(self.path) as file:
             try:
                 return self.expand(json.load(file))

tests/config/bad_conf_cycles.json

@@ -0,0 +1,32 @@
+{
+  "type": "pyaml.pyaml",
+  "instruments":[
+    {
+      "type": "pyaml.instrument",
+      "name": "sr",
+      "energy": 6e9,
+      "simulators": ["../config/bad_conf_cycles.json"],
+      "data_folder": "/data/store",
+      "arrays": [
+        {
+          "type": "pyaml.arrays.hcorrector",
+          "name": "HCORR",
+          "elements": [
+            "SH1A-C01-H",
+            "SH1A-C02-H"
+          ]
+        },
+        {
+          "type": "pyaml.arrays.vcorrector",
+          "name": "VCORR",
+          "elements": ["SH1A-C01-V", "SH1A-C02-V"]
+        }
+      ],
+      "devices": [
+        "sr/quadrupoles/QF1AC01.yaml",
+        "sr/correctors/SH1AC01.yaml",
+        "sr/correctors/SH1AC02.yaml"
+      ]
+    }
+  ]
+}

tests/config/bad_conf_cycles.yml

@@ -0,0 +1,26 @@
+type: pyaml.pyaml
+instruments:
+  - type: pyaml.instrument
+    name: sr
+    energy: 6e9
+    simulators:
+      - type: pyaml.lattice.simulator
+        lattice: sr/lattices/ebs.mat
+        name: design
+    data_folder: /data/store
+    arrays:
+      - type: pyaml.arrays.hcorrector
+        name: HCORR
+        elements:
+          - SH1A-C01-H
+          - SH1A-C02-H
+      - type: pyaml.arrays.vcorrector
+        name: VCORR
+        elements:
+          - SH1A-C01-V
+          - SH1A-C02-V
+    devices:
+      - ../config/bad_conf_cycles.yml # Cycle here
+      - sr/quadrupoles/QF1AC01.yaml
+      - sr/correctors/SH1AC01.yaml
+      - sr/correctors/SH1AC02.yaml

tests/test_factory.py

@@ -1,5 +1,5 @@
 import pytest
-from pyaml import PyAMLConfigException
+from pyaml import PyAMLConfigException, PyAMLException
 from pyaml.configuration.factory import Factory
 from pyaml.pyaml import PyAML, pyaml
 from tests.conftest import MockElement
@@ -28,9 +28,23 @@ def test_factory_with_custom_strategy():
     assert obj.name == "custom_injected"
 
 
-def test_error_location():
-
+@pytest.mark.parametrize("test_file", [
+    "tests/config/bad_conf.yml",
+])
+def test_error_location(test_file):
     with pytest.raises(PyAMLConfigException) as exc:
-        ml: PyAML = pyaml("tests/config/bad_conf.yml")
-
-    assert "at line 7, column 9" in str(exc.value)
+        ml: PyAML = pyaml(test_file)
+    print(str(exc.value))
+    test_file_names = test_file.split("/")
+    test_file_name = test_file_names[len(test_file_names)-1]
+    assert f"{test_file_name} at line 7, column 9" in str(exc.value)
+
+@pytest.mark.parametrize("test_file", [
+    "tests/config/bad_conf_cycles.yml",
+    "tests/config/bad_conf_cycles.json",
+])
+def test_error_cycles(test_file):
+    with pytest.raises(PyAMLException) as exc:
+        ml: PyAML = pyaml(test_file)
+
+    assert "A cycle has been detected" in str(exc.value)