add test cases for Component._encoding concerning #557

Signed-off-by: Felix Stupp <[email protected]>

src/icalendar/tests/test_issue_557_encode_native_parameters.py

@@ -0,0 +1,152 @@
+"""These are tests for Issue #557
+
+TL;DR: Component._encode lost given parameters
+if the object to encode was already of native type,
+making its behavior unexpected.
+
+see https://github.com/collective/icalendar/issues/557"""
+
+
+import unittest
+
+from icalendar.cal import Component
+
+
+class TestComponentEncode(unittest.TestCase):
+    def test_encode_non_native_parameters(self):
+        """Test _encode to add parameters to non-natives"""
+        self.__assert_native_content(self.summary)
+        self.__assert_native_kept_parameters(self.summary)
+
+    def test_encode_native_keep_params_None(self):
+        """_encode should keep parameters on natives
+        if parameters=None
+        """
+        new_sum = self.__add_params(
+            self.summary,
+            parameters=None,
+        )
+        self.__assert_native_content(new_sum)
+        self.__assert_native_kept_parameters(new_sum)
+
+    def test_encode_native_keep_params_empty(self):
+        """_encode should keep paramters on natives
+        if parameters={}
+        """
+        new_sum = self.__add_params(
+            self.summary,
+            parameters={},
+        )
+        self.__assert_native_content(new_sum)
+        self.__assert_native_kept_parameters(new_sum)
+
+    def test_encode_native_append_params(self):
+        """_encode should append paramters on natives
+        keeping old parameters
+        """
+        new_sum = self.__add_params(
+            self.summary,
+            parameters={"X-PARAM": "Test123"},
+        )
+        self.__assert_native_content(new_sum)
+        self.__assert_native_kept_parameters(new_sum)
+        self.assertParameter(new_sum, "X-PARAM", "Test123")
+
+    def test_encode_native_overwrite_params(self):
+        """_encode should overwrite single parameters
+        if they have the same name as old ones"""
+        new_sum = self.__add_params(
+            self.summary,
+            parameters={"LANGUAGE": "de"},
+        )
+        self.__assert_native_content(new_sum)
+        self.assertParameter(new_sum, "LANGUAGE", "de")
+
+    def test_encode_native_remove_params(self):
+        """_encode should remove single parameters
+        if they are explicitly set to None"""
+        new_sum = self.__add_params(
+            self.summary,
+            parameters={"LANGUAGE": None},
+        )
+        self.__assert_native_content(new_sum)
+        self.assertParameterMissing(new_sum, "LANGUAGE")
+
+    def test_encode_native_remove_already_missing(self):
+        """_encode should ignore removing a parameter
+        that was already missing"""
+        self.assertParameterMissing(self.summary, "X-MISSING")
+        new_sum = self.__add_params(
+            self.summary,
+            parameters={"X-MISSING": None},
+        )
+        self.__assert_native_content(new_sum)
+        self.__assert_native_kept_parameters(new_sum)
+        self.assertParameterMissing(self.summary, "X-MISSING")
+
+    def test_encode_native_full_test(self):
+        """full test case with keeping, overwriting & removing properties"""
+        # preperation
+        orig_sum = self.__add_params(
+            self.summary,
+            parameters={
+                "X-OVERWRITE": "overwrite me!",
+                "X-REMOVE": "remove me!",
+                "X-MISSING": None,
+            },
+        )
+        # preperation check
+        self.__assert_native_content(orig_sum)
+        self.__assert_native_kept_parameters(orig_sum)
+        self.assertParameter(orig_sum, "X-OVERWRITE", "overwrite me!")
+        self.assertParameter(orig_sum, "X-REMOVE", "remove me!")
+        self.assertParameterMissing(orig_sum, "X-MISSING")
+        # modification
+        new_sum = self.__add_params(
+            orig_sum,
+            parameters={
+                "X-OVERWRITE": "overwritten",
+                "X-REMOVE": None,
+                "X-MISSING": None,
+            },
+        )
+        # final asserts
+        self.__assert_native_content(new_sum)
+        self.__assert_native_kept_parameters(new_sum)
+        self.assertParameter(new_sum, "X-OVERWRITE", "overwritten")
+        self.assertParameterMissing(new_sum, "X-REMOVE")
+        self.assertParameterMissing(new_sum, "X-MISSING")
+
+    def setUp(self):
+        self.summary = self.__gen_native()
+
+    def __assert_native_kept_parameters(self, obj):
+        self.assertParameter(obj, "LANGUAGE", "en")
+
+    def __assert_native_content(self, obj):
+        self.assertEqual(obj, "English Summary")
+
+    def __add_params(self, obj, parameters):
+        return Component._encode(
+            "SUMMARY",
+            obj,
+            parameters=parameters,
+            encode=True,
+        )
+
+    def __gen_native(self):
+        return Component._encode(
+            "SUMMARY",
+            "English Summary",
+            parameters={
+                "LANGUAGE": "en",
+            },
+            encode=True,
+        )
+
+    def assertParameterMissing(self, obj, name):
+        self.assertNotIn(name, obj.params)
+
+    def assertParameter(self, obj, name, val):
+        self.assertIn(name, obj.params)
+        self.assertEqual(obj.params[name], val)