From 11bd60fc59529dc957dd50fb7816bc068d04f39c Mon Sep 17 00:00:00 2001
From: Jongsu Liam Kim <appleparan@gmail.com>
Date: Fri, 2 Nov 2018 01:32:27 +0900
Subject: [PATCH] fix wrong return type of callback of map function

---
 types/mathjs/index.d.ts      | 2 +-
 types/mathjs/mathjs-tests.ts | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/types/mathjs/index.d.ts b/types/mathjs/index.d.ts
index 71f89b3e1a..8b133c29f7 100644
--- a/types/mathjs/index.d.ts
+++ b/types/mathjs/index.d.ts
@@ -1345,7 +1345,7 @@ declare namespace math {
          * the Matrix/array being traversed.
          * @returns Transformed map of x
          */
-        map(x: Matrix | MathArray, callback: ((value: any, index: any, matrix: Matrix | MathArray) => Matrix | MathArray)): Matrix | MathArray;
+        map(x: Matrix | MathArray, callback: ((value: any, index: any, matrix: Matrix | MathArray) => MathType | string)): Matrix | MathArray;
 
         /**
          * Create a matrix filled with ones. The created matrix can have one or
diff --git a/types/mathjs/mathjs-tests.ts b/types/mathjs/mathjs-tests.ts
index 7c3dfaec35..38aedea488 100644
--- a/types/mathjs/mathjs-tests.ts
+++ b/types/mathjs/mathjs-tests.ts
@@ -270,6 +270,13 @@ Matrices examples
 		math.range('2:-1:-3');
 		math.factorial(math.range('1:6'));
 	}
+
+	// map matrix
+	{
+  	math.map([1, 2, 3], function(value) {
+      return value * value;
+	  });  // returns [1, 4, 9]
+	}
 }
 
 /*