From 7e66b5c54e6eb097e53db62392bdf694f28ebd83 Mon Sep 17 00:00:00 2001
From: Dave Brondsema <dave@brondsema.net>
Date: Mon, 28 Sep 2026 12:11:55 -0400
Subject: [PATCH] support $type op in mim

---
 ming/mim.py            | 21 +++++++++++++++++++++
 ming/tests/test_mim.py | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/ming/mim.py b/ming/mim.py
index b90c68c..a2b5651 100644
--- a/ming/mim.py
+++ b/ming/mim.py
@@ -1022,6 +1022,12 @@ def match(self, key, op, value):
                     if value.lower() in self[field].lower():
                         return True
             return False
+        if op == '$type':
+            wanted = value if isinstance(value, list) else [value]
+            codes = {_BSON_TYPE_ALIASES.get(t, t) for t in wanted}
+            if 'number' in wanted:
+                codes |= {1, 16, 18, 19}
+            return _bson_type_code(val) in codes
         raise NotImplementedError(op)
 
     def _match_regex(self, regex, val):
@@ -1332,6 +1338,21 @@ def setdefault(self, key, default):
         self._orig[key] = default
 
 
+# mongo server's $type aliases; pymongo only has the numeric codes
+_BSON_TYPE_ALIASES = {
+    'double': 1, 'string': 2, 'object': 3, 'array': 4, 'binData': 5, 'objectId': 7, 'bool': 8, 'date': 9,
+    'null': 10, 'regex': 11, 'javascript': 13, 'int': 16, 'timestamp': 17, 'long': 18, 'decimal': 19,
+    'minKey': -1, 'maxKey': 127,
+}
+
+
+def _bson_type_code(val) -> int | None:
+    if val == ():
+        return None
+    code = bson_safe({'': val._orig if isinstance(val, Match) else val})[4]  # type byte of the first element
+    return -1 if code == 0xFF else code  # minKey
+
+
 def _parse_query(v):
     if isinstance(v, dict) and all(k.startswith('$') for k in v.keys()):
         return v.items()
diff --git a/ming/tests/test_mim.py b/ming/tests/test_mim.py
index 0be450e..03c70af 100644
--- a/ming/tests/test_mim.py
+++ b/ming/tests/test_mim.py
@@ -832,6 +832,40 @@ def test_exists(self):
         self.assertIsNone(mim.match({'e': { '$exists': 1 } }, doc))
         self.assertIsNotNone(mim.match({'e': { '$exists': 0 } }, doc))
 
+    def test_type(self):
+        doc = {'s': 'x', 'i': 1, 'l': 2**40, 'f': 1.5, 'b': True, 'n': None, 'o': {'x': 1}, 'a': ['x', 1],
+               'id': bson.ObjectId(), 'dt': datetime(2020, 1, 1), 'bin': bson.Binary(b'x'),
+               'u': uuid.uuid4(), 'js': bson.Code('x'), 'mk': bson.MinKey()}
+        self.assertIsNotNone(mim.match({'s': {'$type': 'string'}}, doc))
+        self.assertIsNotNone(mim.match({'s': {'$type': 2}}, doc))
+        self.assertIsNone(mim.match({'s': {'$type': 'int'}}, doc))
+        self.assertIsNotNone(mim.match({'i': {'$type': 'int'}}, doc))
+        self.assertIsNotNone(mim.match({'l': {'$type': 'long'}}, doc))
+        self.assertIsNotNone(mim.match({'f': {'$type': 'double'}}, doc))
+        self.assertIsNotNone(mim.match({'b': {'$type': 'bool'}}, doc))
+        self.assertIsNone(mim.match({'b': {'$type': 'int'}}, doc))
+        self.assertIsNotNone(mim.match({'n': {'$type': 'null'}}, doc))
+        self.assertIsNotNone(mim.match({'o': {'$type': 'object'}}, doc))
+        self.assertIsNotNone(mim.match({'id': {'$type': 'objectId'}}, doc))
+        self.assertIsNotNone(mim.match({'dt': {'$type': 'date'}}, doc))
+        self.assertIsNotNone(mim.match({'bin': {'$type': 'binData'}}, doc))
+        self.assertIsNotNone(mim.match({'u': {'$type': 'binData'}}, doc))
+        self.assertIsNotNone(mim.match({'js': {'$type': 'javascript'}}, doc))
+        self.assertIsNone(mim.match({'js': {'$type': 'string'}}, doc))
+        self.assertIsNotNone(mim.match({'mk': {'$type': 'minKey'}}, doc))
+        self.assertIsNotNone(mim.match({'mk': {'$type': -1}}, doc))
+        self.assertIsNone(mim.match({'missing': {'$type': 'null'}}, doc))
+        for f in ('i', 'l', 'f'):
+            self.assertIsNotNone(mim.match({f: {'$type': 'number'}}, doc))
+        self.assertIsNone(mim.match({'b': {'$type': 'number'}}, doc))
+        self.assertIsNotNone(mim.match({'n': {'$type': ['string', 'null']}}, doc))
+        self.assertIsNone(mim.match({'i': {'$type': ['string', 'null']}}, doc))
+        # arrays match on the array itself or any element
+        self.assertIsNotNone(mim.match({'a': {'$type': 'array'}}, doc))
+        self.assertIsNotNone(mim.match({'a': {'$type': 'string'}}, doc))
+        self.assertIsNotNone(mim.match({'a': {'$type': 'int'}}, doc))
+        self.assertIsNone(mim.match({'a': {'$type': 'double'}}, doc))
+
     def test_all(self):
         doc = { 'c': [ 1, 2 ] }
         self.assertIsNotNone(mim.match({'c': {'$all': [] } }, doc))