Merge ~kissiel/plainbox:add-none-stock-report into plainbox:master

[Maciej Kisielewski]

add option to specify 'none' as a stock_reports value in configs

To test it have a launcher that specifies

stock_reports = none

It should behave in the same way as

stock_reports =

Fixes LP:1741116

[Maciej Kisielewski (kissiel)]

The documentation for the option will come in checkbox-ng's branch that actually has the logic to handle the 'none' value.

[Jonathan Cave (jocave)]

Had a look at the code and it looks good to me.

The only criticism I have is that it wasn't all that clear to me what the OneOrTheOtherValidator was actually going to do from the name! May be something like DisjointSetValidator would sound a bit more formal and clear?

Approving otherwise.

review: Approve

diff --git a/plainbox/impl/launcher.py b/plainbox/impl/launcher.py
index 897d80c..034c613 100644
--- a/plainbox/impl/launcher.py
+++ b/plainbox/impl/launcher.py
@@ -109,9 +109,14 @@ class LauncherDefinition1(LauncherDefinition):
     stock_reports = config.Variable(
         section='launcher',
         kind=list,
-        validator_list=[config.SubsetValidator({
-            'text', 'certification', 'certification-staging',
-            'submission_files'})],
+        validator_list=[
+            config.SubsetValidator({
+                'text', 'certification', 'certification-staging',
+                'submission_files', 'none'}),
+            config.OneOrTheOtherValidator(
+                {'none'}, {'text', 'certification', 'certification-staging',
+                           'submission_files'}),
+            ],
         default=['text', 'certification', 'submission_files'],
         help_text=_('List of stock reports to use'))
 
diff --git a/plainbox/impl/secure/config.py b/plainbox/impl/secure/config.py
index 5d3b0e8..6d4cdf8 100644
--- a/plainbox/impl/secure/config.py
+++ b/plainbox/impl/secure/config.py
@@ -834,6 +834,28 @@ class SubsetValidator(IValidator):
             return False
 
 
+class OneOrTheOtherValidator(IValidator):
+    """
+    A validator ensuring that values only from one or the other set are used.
+    """
+    def __init__(self, a_set, b_set):
+        # the sets have to be disjoint
+        assert(not a_set & b_set)
+        self.a_set = set(a_set)
+        self.b_set = set(b_set)
+
+    def __call__(self, variable, values):
+        has_common_with_a = bool(self.a_set & set(values))
+        has_common_with_b = bool(self.b_set & set(values))
+        if has_common_with_a and has_common_with_b:
+            return _('{} can only use values from {} or from {}'.format(
+                variable.name, self.a_set, self.b_set))
+
+    def __eq__(self, other):
+        if isinstance(other, OneOrTheOtherValidator):
+            return self.a_set == other.a_set and self.b_set == other.b_set
+
+
 @understands_Unset
 class NotUnsetValidator(IValidator):
     """
diff --git a/plainbox/impl/secure/test_config.py b/plainbox/impl/secure/test_config.py
index ce6d5d0..1efab12 100644
--- a/plainbox/impl/secure/test_config.py
+++ b/plainbox/impl/secure/test_config.py
@@ -32,6 +32,7 @@ from plainbox.impl.secure.config import ConfigMetaData
 from plainbox.impl.secure.config import KindValidator
 from plainbox.impl.secure.config import NotEmptyValidator
 from plainbox.impl.secure.config import NotUnsetValidator
+from plainbox.impl.secure.config import OneOrTheOtherValidator
 from plainbox.impl.secure.config import PatternValidator
 from plainbox.impl.secure.config import ParametricSection
 from plainbox.impl.secure.config import PlainBoxConfigParser, Config
@@ -565,3 +566,43 @@ class NotEmptyValidatorTests(TestCase):
         self.assertTrue(NotEmptyValidator("?") == NotEmptyValidator("?"))
         self.assertTrue(NotEmptyValidator() != NotEmptyValidator("?"))
         self.assertTrue(NotEmptyValidator() != object())
+
+
+class OneOrTheOtherValidatorTests(TestCase):
+
+    class _Config(Config):
+        var = Variable("The Name", kind=list)
+
+    def test_pass_validation(self):
+        validator = OneOrTheOtherValidator({'foo'}, {'bar'})
+        value = ['foo']
+        self.assertIsNone(validator(self._Config.var, value))
+        value = ['bar']
+        self.assertIsNone(validator(self._Config.var, value))
+
+    def test_fail_validation(self):
+        validator = OneOrTheOtherValidator({'foo'}, {'bar'})
+        value = ['foo', 'bar']
+        self.assertEquals(
+            validator(self._Config.var, value),
+            "The Name can only use values from {'foo'} or from {'bar'}")
+
+    def test_pass_empty(self):
+        validator = OneOrTheOtherValidator({'foo'}, {'bar'})
+        value = []
+        self.assertIsNone(validator(self._Config.var, value))
+
+    def test_comparison_works(self):
+        self.assertEqual(
+            OneOrTheOtherValidator({'foo'}, {'bar'}),
+            OneOrTheOtherValidator({'foo'}, {'bar'})
+        )
+        self.assertEqual(
+            OneOrTheOtherValidator({1, 2}, {3, 4}),
+            OneOrTheOtherValidator({2, 1}, {4, 3})
+        )
+        self.assertNotEqual(
+            OneOrTheOtherValidator({1}, {2}),
+            OneOrTheOtherValidator({1}, {'foo'})
+        )
+        self.assertNotEqual(OneOrTheOtherValidator({1}, {2}), object())