From e9ecb63b333c8154d839b956378db8a4d37d916f Mon Sep 17 00:00:00 2001
From: Miloslav Nenadal <nenadalm@gmail.com>
Date: Fri, 7 Jul 2017 14:42:36 +0200
Subject: [PATCH] [ramda]: Improve map definition

---
 types/ramda/index.d.ts     |  2 ++
 types/ramda/ramda-tests.ts | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/types/ramda/index.d.ts b/types/ramda/index.d.ts
index e30c95f8be..1697ff4341 100644
--- a/types/ramda/index.d.ts
+++ b/types/ramda/index.d.ts
@@ -919,6 +919,8 @@ declare namespace R {
         map<T, U>(fn: (x: T) => U, list: T[]): U[];
         map<T, U>(fn: (x: T) => U, obj: Functor<T>): Functor<U>; // used in functors
         map<T, U>(fn: (x: T) => U): (list: T[]) => U[];
+        map<T extends object, U extends {[P in keyof T]: U[P]}>(fn: (x: T[keyof T]) => U[keyof T], obj: T): U;
+        map<T extends object, U extends {[P in keyof T]: U[P]}>(fn: (x: T[keyof T]) => U[keyof T]): (obj: T) => U;
 
         /**
          * The mapAccum function behaves like a combination of map and reduce.
diff --git a/types/ramda/ramda-tests.ts b/types/ramda/ramda-tests.ts
index 18a5ed4e7d..908c88828a 100644
--- a/types/ramda/ramda-tests.ts
+++ b/types/ramda/ramda-tests.ts
@@ -753,6 +753,24 @@ interface Obj {
     R.map((x: number) => x - 1, numberFunctor); // => "Hello World"
 };
 
+() => {
+    interface A {
+        a: number;
+        b: number;
+    }
+
+    interface B {
+        a: string;
+        b: string;
+    }
+
+    R.map<A, A>(R.inc, {a: 1, b: 2});
+    R.map<A, B>(R.toString, {a: 1, b: 2});
+
+    R.map<A, A>(R.inc)({a: 1, b: 2});
+    R.map<A, B>(R.toString)({a: 1, b: 2});
+};
+
 () => {
     let digits = ["1", "2", "3", "4"];