utils: add validation errors functions (#6)

The functions could be used from API scripts
to raise generic and validation errors

src/nethsec/utils/__init__.py

@@ -323,3 +323,50 @@ def get_group_macs(uci, group):
     for u in uci.get('objects', group, 'user', list=True, default=[]):
         macs = macs + get_user_macs(uci, u)
     return macs
+
+
+def validation_errors(errors):
+    '''
+    Generate a validation error for the APIs from an array.
+
+    Arguments:
+      - errors -- An array of array errors
+
+    Each array element is an array composed by 3 parameters:
+      - the name of the parameter
+      - the validation error reason
+      - the parameter original value that caused the error
+
+    Returns:
+      - A validation error object
+    '''
+    verrors = []
+    for e in errors:
+        verrors.append({"parameter": e[0], "message": e[1].strip().replace(" ", "_").lower(), "value": e[2]})
+
+    return {"validation": {"errors": verrors}}
+
+def validation_error(parameter, message="", value=""):
+    '''
+    Generate a validation error for the APIs.
+
+    Arguments:
+      - parameter -- The name of the parameter
+      - message -- The validation error reason, default is empty
+      - value -- The parmeter original value that caused the error
+
+    Returns:
+      - A validation error object
+    '''
+    return validation_errors([[parameter, message, value]])
+
+def generic_error(error):
+    '''
+    Generate a generic error for the APIs.
+
+    Arguments:
+      - message -- An error message
+    Returns:
+      - A validation error object
+    '''
+    return {"error": error.strip().replace(" ", "_").lower()}

tests/test_utils.py

@@ -221,3 +221,20 @@ def test_get_random_id():
     assert len(id1) == 11
     assert id1[0:3] == "ns_"
     assert id1 != id2
+
+def test_error():
+    obj = utils.generic_error("my Error ")
+    assert obj == {"error": "my_error"}
+
+def test_validation_error():
+    er1 = utils.validation_error("param1", "my Error ", "val1")
+    assert er1 == {"validation": {"errors": [{"parameter": "param1", "message": "my_error", "value": "val1"}]}}
+    er2 = utils.validation_error("param1")
+    assert er2 == {"validation": {"errors": [{"parameter": "param1", "message": "", "value": ""}]}}
+
+def test_validation_errors():
+    er1 = utils.validation_errors([
+        ["param1", " my Error ", "val1"],
+        ["param2", " invalid_value ", False],
+        ])
+    assert er1 == {"validation": {"errors": [{"parameter": "param1", "message": "my_error", "value": "val1"}, {"parameter": "param2", "message": "invalid_value", "value": False}]}}