Add TypeScript error when filtering on field not in schema

As a developer, I'd like the type system to catch errors I make, like
trying to query on a field that doesn't exist, or when I have made a
typo in an existing field name.

Previously, querying for these fields outside the schema would pass type
checks because the `Filter<TSchema>` type included a union with
`RootFilterOperators<WithId<TSchema>>`, and `RootFilterOperators` was
defined as `extends Document`. The BSON `Document` type itself is an
object with the index property `{ [key: string]: any }`, meaning that it
would match documents with any keys!

So, while our type checks would give us an error if we tried to pass the
wrong type into a filter expression, trying to use an unknown field name
would instead compare the value to the `any` type.

By removing the `extends Document` clause of the `RootFilterOperators`
type definition, we get much stronger guarantees from the `Filter` type.

Author: noahsilas

src/mongo_types.ts

@@ -90,7 +90,7 @@ export type AlternativeType<T> = T extends ReadonlyArray<infer U>
 export type RegExpOrString<T> = T extends string ? BSONRegExp | RegExp | T : T;
 
 /** @public */
-export interface RootFilterOperators<TSchema> extends Document {
+export interface RootFilterOperators<TSchema> {
   $and?: Filter<TSchema>[];
   $nor?: Filter<TSchema>[];
   $or?: Filter<TSchema>[];

test/types/community/collection/filterQuery.test-d.ts

@@ -126,6 +126,11 @@ expectType<WithId<PetModel>[]>(
 expectType<WithId<PetModel>[]>(
   await collectionT.find({ name: new BSONRegExp('MrMeow', 'i') }).toArray()
 );
+
+/// it should not accept fields that are not in the schema
+type FT = Filter<PetModel>;
+expectNotType<FT>({ missing: true });
+
 /// it should not accept wrong types for string fields
 expectNotType<Filter<PetModel>>({ name: 23 });
 expectNotType<Filter<PetModel>>({ name: { suffix: 'Jr' } });
@@ -361,9 +366,11 @@ expectError(
     otherField: new ObjectId()
   })
 );
-nonObjectIdCollection.find({
-  fieldThatDoesNotExistOnSchema: new ObjectId()
-});
+expectError(
+  nonObjectIdCollection.find({
+    fieldThatDoesNotExistOnSchema: new ObjectId()
+  })
+);
 
 // we only forbid objects that "look like" object ids, so other random objects are permitted
 nonObjectIdCollection.find({