test: add exception trapping and printing info

tests/army/frame/caseBase.py

@@ -482,19 +482,39 @@ class TBase:
 
     # generate new json file
     def genNewJson(self, jsonFile, modifyFunc=None):
-        with open(jsonFile, 'r', encoding='utf-8') as f:
-            data = json.load(f)
+        try:
+            with open(jsonFile, 'r', encoding='utf-8') as f:
+                data = json.load(f)
+        except FileNotFoundError:
+            tdLog.info(f"the specified json file '{jsonFile}' was not found.")
+            return None
+        except Exception as e:
+            tdLog.info(f"error reading the json file: {e}")
+            return None
         
         if callable(modifyFunc):
             modifyFunc(data)
         
         tempDir = os.path.join(tempfile.gettempdir(), 'json_templates')
-        os.makedirs(tempDir, exist_ok=True)
+        try:
+            os.makedirs(tempDir, exist_ok=True)
+        except PermissionError:
+            tdLog.info(f"no sufficient permissions to create directory at '{tempDir}'.")
+            return None
+        except Exception as e:
+            tdLog.info(f"error creating temporary directory: {e}")
+            return None
+        
         tempPath = os.path.join(tempDir, f"temp_{uuid.uuid4().hex}.json")
 
-        with open(tempPath, 'w', encoding='utf-8') as f:
-            json.dump(data, f, indent=2, ensure_ascii=False)
+        try:
+            with open(tempPath, 'w', encoding='utf-8') as f:
+                json.dump(data, f, indent=2, ensure_ascii=False)
+        except Exception as e:
+            tdLog.info(f"error writing to temporary json file: {e}")
+            return None
 
+        tdLog.info(f"create temporary json file successfully, file: {tempPath}")
         return tempPath
 
     # delete file