From d3cf467af3c37cd3e1d948dc89260fd7dfd73354 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=97=E9=9B=86=E5=9B=A2?= <linjituan@guorou.tv>
Date: Thu, 27 Jun 2019 01:30:37 +0800
Subject: [PATCH] ramda: add support of applying `chain` to function type
 argument (#36078)

* ramda: add support of applying `chain` to function type argument

* lint

* add test for `chain`
---
 types/ramda/index.d.ts     | 2 ++
 types/ramda/ramda-tests.ts | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/types/ramda/index.d.ts b/types/ramda/index.d.ts
index 0994fe3651..9c55fae594 100644
--- a/types/ramda/index.d.ts
+++ b/types/ramda/index.d.ts
@@ -28,6 +28,7 @@
 //                 Krantisinh Deshmukh <https://github.com/krantisinh>
 //                 Pierre-Antoine Mills <https://github.com/pirix-gh>
 //                 Brekk Bockrath <https://github.com/brekk>
+//                 Jituan Lin <https://github.com/jituanlin>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 3.3
 
@@ -964,6 +965,7 @@ declare namespace R {
          */
         chain<T, U>(fn: (n: T) => ReadonlyArray<U>, list: ReadonlyArray<T>): U[];
         chain<T, U>(fn: (n: T) => ReadonlyArray<U>): (list: ReadonlyArray<T>) => U[];
+        chain<X0, X1, R>(fn: (x0: X0, x1: X1) => R, fn1: (x1: X1) => X0): (x1: X1) => R;
 
         /**
          * Restricts a number to be within a range.
diff --git a/types/ramda/ramda-tests.ts b/types/ramda/ramda-tests.ts
index cb16a1c2a9..5b63b3123f 100644
--- a/types/ramda/ramda-tests.ts
+++ b/types/ramda/ramda-tests.ts
@@ -723,6 +723,11 @@ R.times(i, 5);
 
     R.chain(duplicate, [1, 2, 3]); // => [1, 1, 2, 2, 3, 3]
     R.chain(duplicate)([1, 2, 3]); // => [1, 1, 2, 2, 3, 3]
+    const result1: number[] = R.chain<number, number[], number[]>(R.append, R.head)([
+        1,
+        2,
+        3
+    ]); // => [1, 2, 3, 1]
 };
 
 () => {