Implement __eq__ for all Query subclasses

Tests are a bit light.

beets/dbcore/query.py

@@ -73,6 +73,9 @@ class Query(object):
         """
         raise NotImplementedError
 
+    def __eq__(self, other):
+        return type(self) == type(other)
+
 
 class FieldQuery(Query):
     """An abstract query that searches in a specific field for a
@@ -106,6 +109,10 @@ class FieldQuery(Query):
     def match(self, item):
         return self.value_match(self.pattern, item.get(self.field))
 
+    def __eq__(self, other):
+        return super(FieldQuery, self).__eq__(other) and \
+               self.field == other.field and self.pattern == other.pattern
+
 
 class MatchQuery(FieldQuery):
     """A query that looks for exact matches in an item field."""
@@ -120,8 +127,7 @@ class MatchQuery(FieldQuery):
 class NoneQuery(FieldQuery):
 
     def __init__(self, field, fast=True):
-        self.field = field
-        self.fast = fast
+        super(NoneQuery, self).__init__(field, None, fast)
 
     def col_clause(self):
         return self.field + " IS NULL", ()
@@ -337,6 +343,10 @@ class CollectionQuery(Query):
         clause = (' ' + joiner + ' ').join(clause_parts)
         return clause, subvals
 
+    def __eq__(self, other):
+        return super(CollectionQuery, self).__eq__(other) and \
+               self.subqueries == other.subqueries
+
 
 class AnyFieldQuery(CollectionQuery):
     """A query that matches if a given FieldQuery subclass matches in
@@ -362,6 +372,10 @@ class AnyFieldQuery(CollectionQuery):
                 return True
         return False
 
+    def __eq__(self, other):
+        return super(AnyFieldQuery, self).__eq__(other) and \
+               self.query_class == other.query_class
+
 
 class MutableCollectionQuery(CollectionQuery):
     """A collection query whose subqueries may be modified after the

test/test_query.py

@@ -60,6 +60,16 @@ class AnyFieldQueryTest(_common.LibTestCase):
                                        dbcore.query.SubstringQuery)
         self.assertEqual(self.lib.items(q).get(), None)
 
+    def test_eq(self):
+        q1 = dbcore.query.AnyFieldQuery('foo', ['bar'],
+                                        dbcore.query.SubstringQuery)
+        q2 = dbcore.query.AnyFieldQuery('foo', ['bar'],
+                                        dbcore.query.SubstringQuery)
+        self.assertEqual(q1, q2)
+
+        q2.query_class = None
+        self.assertNotEqual(q1, q2)
+
 
 class AssertsMixin(object):
     def assert_items_matched(self, results, titles):
@@ -344,6 +354,16 @@ class MatchTest(_common.TestCase):
     def test_open_range(self):
         dbcore.query.NumericQuery('bitrate', '100000..')
 
+    def test_eq(self):
+        q1 = dbcore.query.MatchQuery('foo', 'bar')
+        q2 = dbcore.query.MatchQuery('foo', 'bar')
+        q3 = dbcore.query.MatchQuery('foo', 'baz')
+        q4 = dbcore.query.StringFieldQuery('foo', 'bar')
+        self.assertEqual(q1, q2)
+        self.assertNotEqual(q1, q3)
+        self.assertNotEqual(q1, q4)
+        self.assertNotEqual(q3, q4)
+
 
 class PathQueryTest(_common.LibTestCase, TestHelper, AssertsMixin):
     def setUp(self):