From ed82b9ef70ab6fdf9d5d4bec1686a9662ffbc657 Mon Sep 17 00:00:00 2001
From: Karim Alibhai <karim@alibhai.co>
Date: Wed, 9 Jan 2019 00:06:49 -0500
Subject: [PATCH 1/2] Add(mongoose): generics for schema methods

---
 types/mongoose/index.d.ts | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/types/mongoose/index.d.ts b/types/mongoose/index.d.ts
index 14e965dd5f..df91675e15 100644
--- a/types/mongoose/index.d.ts
+++ b/types/mongoose/index.d.ts
@@ -737,7 +737,7 @@ declare module "mongoose" {
    * section schema.js
    * http://mongoosejs.com/docs/api.html#schema-js
    */
-  class Schema extends events.EventEmitter {
+  class Schema<T = any> extends events.EventEmitter {
     /**
      * Schema constructor.
      * When nesting schemas, (children in the example above), always declare
@@ -789,8 +789,10 @@ declare module "mongoose" {
      * Adds an instance method to documents constructed from Models compiled from this schema.
      * If a hash of name/fn pairs is passed as the only argument, each name/fn pair will be added as methods.
      */
-    method(method: string, fn: Function): this;
-    method(methodObj: { [name: string]: Function }): this;
+    method<F extends keyof T>(method: F, fn: T[F]): this;
+    method(methodObj: {
+      [F in keyof T]: T[F]
+    }): this;
 
     /**
      * Gets/sets schema paths.
@@ -954,7 +956,9 @@ declare module "mongoose" {
     static reserved: any;
 
     /** Object of currently defined methods on this schema. */
-    methods: any;
+    methods: {
+      [F in keyof T]: T[F]
+    };
     /** Object of currently defined statics on this schema. */
     statics: any;
     /** Object of currently defined query helpers on this schema. */

From 4f0e246373e1afbae5ddb087012893fba4dc3587 Mon Sep 17 00:00:00 2001
From: Karim Alibhai <karim@alibhai.co>
Date: Wed, 9 Jan 2019 00:35:38 -0500
Subject: [PATCH 2/2] Add: animal interface to tests

---
 types/mongoose/mongoose-tests.ts | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/types/mongoose/mongoose-tests.ts b/types/mongoose/mongoose-tests.ts
index 7d23e6be6b..8f5914d9dd 100644
--- a/types/mongoose/mongoose-tests.ts
+++ b/types/mongoose/mongoose-tests.ts
@@ -522,12 +522,15 @@ mongoose.Schema.reserved.hasOwnProperty('');
 /* inherited properties */
 schema.addListener('e', cb);
 /* practical examples */
-var animalSchema = new mongoose.Schema({
+interface Animal {
+  findSimilarTypes(cb: any): Promise<Animal>
+}
+var animalSchema = new mongoose.Schema<Animal>({
   name: String,
   type: String
 });
-animalSchema.methods.findSimilarTypes = function (cb: any) {
-  return this.model('Aminal').find({ type: this.type }, cb);
+animalSchema.methods.findSimilarTypes = function (cb) {
+  return this.model('Animal').find({ type: this.type }, cb);
 };
 var Animal: any = mongoose.model('Animal', animalSchema);
 var dog: any = new Animal({type: 'dog'});