fix(index.d.ts): avoid UnpackedIntersection making `findOne().populat…

…e()` result non-nullable Fix #11041
Automattic · Jan 23, 2022 · c530400 · c530400
1 parent 6c9a9ca
commit c530400
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Showing 3 changed files with 25 additions and 3 deletions.
diff --git a/index.d.ts b/index.d.ts
@@ -2124,6 +2124,7 @@ declare module 'mongoose' {
   type QueryWithHelpers<ResultType, DocType, THelpers = {}, RawDocType = DocType> = Query<ResultType, DocType, THelpers, RawDocType> & THelpers;
 
   type UnpackedIntersection<T, U> = T extends (infer V)[] ? (V & U)[] : T & U;
+  type UnpackedIntersectionWithNull<T, U> = T extends null ? UnpackedIntersection<T, U> | null : UnpackedIntersection<T, U>;
 
   class Query<ResultType, DocType, THelpers = {}, RawDocType = DocType> {
     _mongooseOptions: MongooseQueryOptions;
@@ -2407,8 +2408,8 @@ declare module 'mongoose' {
     polygon(path: string, ...coordinatePairs: number[][]): this;
 
     /** Specifies paths which should be populated with other documents. */
-    populate<Paths = {}>(path: string | any, select?: string | any, model?: string | Model<any, THelpers>, match?: any): QueryWithHelpers<UnpackedIntersection<ResultType, Paths>, DocType, THelpers, RawDocType>;
-    populate<Paths = {}>(options: PopulateOptions | Array<PopulateOptions>): QueryWithHelpers<UnpackedIntersection<ResultType, Paths>, DocType, THelpers, RawDocType>;
+    populate<Paths = {}>(path: string | any, select?: string | any, model?: string | Model<any, THelpers>, match?: any): QueryWithHelpers<UnpackedIntersectionWithNull<ResultType, Paths>, DocType, THelpers, RawDocType>;
+    populate<Paths = {}>(options: PopulateOptions | Array<PopulateOptions>): QueryWithHelpers<UnpackedIntersectionWithNull<ResultType, Paths>, DocType, THelpers, RawDocType>;
 
     /** Get/set the current projection (AKA fields). Pass `null` to remove the current projection. */
     projection(fields?: any | null): this;

diff --git a/test/typescript/main.test.js b/test/typescript/main.test.js
@@ -46,8 +46,9 @@ describe('typescript syntax', function() {
   it('queries', function() {
     const errors = runTest('queries.ts', { strict: true });
     printTSErrors(errors);
-    assert.equal(errors.length, 1);
+    assert.equal(errors.length, 2);
     assert.ok(errors[0].messageText.includes('notAQueryHelper'), errors[0].messageText);
+    assert.ok(errors[1].messageText.messageText.includes('| null\' is not assignable'), errors[0].messageText);
   });
 
   it('create', function() {

diff --git a/test/typescript/queries.ts b/test/typescript/queries.ts
@@ -184,4 +184,24 @@ function gh10786() {
   if (true) {
     updateQuery.phone = 'XXXX';
   }
+}
+
+async function gh11041(): Promise<void> {
+  interface User {
+    name: string;
+    email: string;
+    avatar?: string;
+  }
+
+  // 2. Create a Schema corresponding to the document interface.
+  const schema = new Schema<User>({
+    name: { type: String, required: true },
+    email: { type: String, required: true },
+    avatar: String
+  });
+
+  // 3. Create a Model.
+  const MyModel = model<User>('User', schema);
+
+  const maybeDoc3: { _id: Types.ObjectId } = await MyModel.findOne({}).populate('someField').exec();
 }