Add windows build number filter object

docs/user/filters.rst

@@ -29,6 +29,7 @@ Filter Objects
 .. autoclass:: PrefExistsFilter()
 .. autoclass:: PrefCompareFilter()
 .. autoclass:: PrefUserSetFilter()
+.. autoclass:: WindowsBuildNumberFilter()
 
 
 Filter Expressions

normandy/recipes/filters.py

@@ -48,6 +48,22 @@ class BaseFilter(serializers.Serializer):
         """Render this filter to a JEXL expression"""
         raise NotImplementedError
 
+    def to_operator(self, comparison):
+        if comparison == "equal":
+            return "=="
+        elif comparison == "not_equal":
+            return "!="
+        elif comparison == "greater_than":
+            return ">"
+        elif comparison == "greater_than_equal":
+            return ">="
+        elif comparison == "less_than":
+            return "<"
+        elif comparison == "less_than_equal":
+            return "<="
+        else:
+            raise serializers.ValidationError(f"Unrecognized comparison {comparison!r}")
+
 
 class ChannelFilter(BaseFilter):
     """
@@ -547,6 +563,24 @@ class DateRangeFilter(BaseFilter):
         return {"jexl.transform.date"}
 
 
+class WindowsBuildNumberFilter(BaseFilter):
+    type = "windows_build_number"
+    build_number = serializers.IntegerField()
+    comparison = serializers.CharField()
+
+    def to_jexl(self):
+        comparison = self.initial_data["comparison"]
+        build_number = self.initial_data["build_number"]
+
+        symbol = self.to_operator(comparison)
+
+        return f"(normandy.os.isWindows && normandy.os.windowsBuildNumber {symbol} {build_number})"
+
+    @property
+    def capabilities(self):
+        return set()
+
+
 class ProfileCreateDateFilter(BaseFilter):
     """
     This filter is meant to distinguish between new and existing users.

normandy/recipes/tests/test_filters.py

@@ -15,6 +15,7 @@ from normandy.recipes.filters import (
     PrefCompareFilter,
     PrefExistsFilter,
     PrefUserSetFilter,
+    WindowsBuildNumberFilter,
 )
 from normandy.recipes.tests import ChannelFactory, LocaleFactory, CountryFactory
 
@@ -121,6 +122,33 @@ class TestDateRangeFilter(FilterTestsBase):
         }
 
 
+class TestWindowsBuildNumberFiter(FilterTestsBase):
+    def create_basic_filter(self, build_number=12345, comparison="equal"):
+        return WindowsBuildNumberFilter.create(build_number=build_number, comparison=comparison)
+
+    @pytest.mark.parametrize(
+        "comparison,symbol",
+        [
+            ("equal", "=="),
+            ("greater_than", ">"),
+            ("greater_than_equal", ">="),
+            ("less_than", "<"),
+            ("less_than_equal", "<="),
+        ],
+    )
+    def test_generates_jexl_number_ops(self, comparison, symbol):
+        filter = self.create_basic_filter(comparison=comparison)
+        assert (
+            filter.to_jexl()
+            == f"(normandy.os.isWindows && normandy.os.windowsBuildNumber {symbol} 12345)"
+        )
+
+    def test_generates_jexl_error_on_bad_comparison(self):
+        filter = self.create_basic_filter(comparison="typo")
+        with pytest.raises(serializers.ValidationError):
+            filter.to_jexl()
+
+
 class TestChannelFilter(FilterTestsBase):
     def create_basic_filter(self, channels=None):
         if channels: