[mongodb] Fix support for optional fields in $pull and $push (#43892)

types/mongodb/index.d.ts

@@ -31,6 +31,7 @@
 //                 Linus Unnebäck <https://github.com/LinusU>
 //                 Richard Bateman <https://github.com/taxilian>
 //                 Igor Strebezhev <https://github.com/xamgore>
+//                 Valentin Agachi <https://github.com/avaly>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 3.0
 
@@ -1226,9 +1227,9 @@ export interface Collection<TSchema extends { [key: string]: any } = DefaultSche
 }
 
 /** Update Query */
-type KeysOfAType<TSchema, Type> = { [key in keyof TSchema]: TSchema[key] extends Type ? key : never }[keyof TSchema];
+type KeysOfAType<TSchema, Type> = { [key in keyof TSchema]: NonNullable<TSchema[key]> extends Type ? key : never }[keyof TSchema];
 type KeysOfOtherType<TSchema, Type> = {
-    [key in keyof TSchema]: TSchema[key] extends Type ? never : key;
+    [key in keyof TSchema]: NonNullable<TSchema[key]> extends Type ? never : key;
 }[keyof TSchema];
 
 type AcceptedFields<TSchema, FieldType, AssignableType> = {

types/mongodb/test/collection/findX.ts

@@ -43,6 +43,8 @@ async function run() {
     const _b: Bag = b; // b is larger than bag and may contain extra properties
   });
   collection.findOne<Bag>({ color: 'white' }).then(b => {
-    b.cost;
+    if (b) {
+      b.cost; // $ExpectType number
+    }
   });
 }

types/mongodb/test/collection/insertX.ts

@@ -165,13 +165,13 @@ async function run() {
   indexTypeResult1.insertedId;            // $ExpectType ObjectId
   // should not remove types of existing fields
   indexTypeResult1.ops[0].stringField;    // $ExpectType string
-  indexTypeResult1.ops[0].numberField;    // $ExpectType number
+  indexTypeResult1.ops[0].numberField;    // $ExpectType number | undefined
   // should assign "any" type to any other field
   indexTypeResult1.ops[0].randomField;    // $ExpectType any
   // should do the same for insertMany
   indexTypeResultMany1.ops[0]._id;          // $ExpectType ObjectId
   indexTypeResultMany1.insertedIds;         // $ExpectType { [key: number]: ObjectId; }
-  indexTypeResultMany1.ops[0].numberField;  // $ExpectType number
+  indexTypeResultMany1.ops[0].numberField;  // $ExpectType number | undefined
   indexTypeResultMany1.ops[0].stringField;  // $ExpectType string
   indexTypeResultMany1.ops[0].randomField;  // $ExpectType any
 

types/mongodb/test/collection/updateX.ts

@@ -112,6 +112,7 @@ async function run() {
 
     buildUpdateQuery({ $pull: { fruitTags: 'a' } });
     buildUpdateQuery({ $pull: { fruitTags: { $in: ['a'] } } });
+    buildUpdateQuery({ $pull: { maybeFruitTags: 'apple' } });
     buildUpdateQuery({ $pull: { 'dot.notation': 1 } });
     buildUpdateQuery({ $pull: { 'subInterfaceArray.$[]': { $in: ['a'] } } });
     buildUpdateQuery({ $pull: { subInterfaceArray: { field1: 'a' } }});
@@ -124,6 +125,7 @@ async function run() {
     buildUpdateQuery({ $push: { fruitTags: { $each: ['a'], $sort: 1 } } });
     buildUpdateQuery({ $push: { fruitTags: { $each: ['a'], $sort: -1 } } });
     buildUpdateQuery({ $push: { fruitTags: { $each: ['a'], $sort: { 'sub.field': -1 } } } });
+    buildUpdateQuery({ $push: { maybeFruitTags: 'apple' } });
     // buildUpdateQuery({ $push: { fruitTags: { $each: ['stringField'] } } });
     // buildUpdateQuery({ $push: { 'dot.notation': 1 } });
     // buildUpdateQuery({ $push: { 'subInterfaceArray.$[]': { $in: ['a'] } } });

types/mongodb/test/stats.ts

@@ -9,5 +9,7 @@ async function run() {
   collection.stats((err: MongoError, stats: CollStats) => {});
 
   const stats = await collection.stats();
-  stats.wiredTiger.cache['bytes currently in the cache']; // $ExpectType number
+  if (stats.wiredTiger) {
+    stats.wiredTiger.cache['bytes currently in the cache']; // $ExpectType number
+  }
 }

types/mongodb/tsconfig.json

@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [