From eee9aea11b327c733ce37453638090c0e9678ee0 Mon Sep 17 00:00:00 2001
From: Lucas Brandstaetter <lucas@brandstaetter.tech>
Date: Sat, 16 Nov 2019 02:37:26 +0100
Subject: [PATCH 1/2] Update typings

Typings for the convert should include `undefined` or `null`,
as they are handled in the convert function.
---
 index.d.ts            | 7 ++++++-
 package.json          | 3 ++-
 unist-util-is-test.ts | 2 ++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index f05d502..cd2ef07 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -37,7 +37,12 @@ declare namespace unistUtilIs {
    *
    * @typeParam T type of node that passes test
    */
-  type Test<T extends Node> = TestType<T> | TestObject<T> | TestFunction<T>
+  type Test<T extends Node> =
+    | TestType<T>
+    | TestObject<T>
+    | TestFunction<T>
+    | null
+    | undefined
 }
 
 /**
diff --git a/package.json b/package.json
index 12fcb8e..ff77971 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,8 @@
   "author": "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)",
   "contributors": [
     "Titus Wormer <tituswormer@gmail.com> (https://wooorm.com)",
-    "Christian Murphy <christian.murphy.42@gmail.com>"
+    "Christian Murphy <christian.murphy.42@gmail.com>",
+    "Lucas Brandstaetter <lucas@brandstaetter.tech> (https://github.com/Roang-zero1)"
   ],
   "files": [
     "index.js",
diff --git a/unist-util-is-test.ts b/unist-util-is-test.ts
index 3ec9946..85c896e 100644
--- a/unist-util-is-test.ts
+++ b/unist-util-is-test.ts
@@ -183,3 +183,5 @@ convert<Element>({type: 'heading', depth: 2})
 convert<Heading>(isHeading)
 // $ExpectError
 convert<Element>(isHeading)
+convert<Node>(null)
+convert<Node>(undefined)

From 53732b333197ee82146bab1fa7f3ded3eacf5abd Mon Sep 17 00:00:00 2001
From: Lucas B <lucas@brandstaetter.tech>
Date: Sat, 16 Nov 2019 14:39:53 +0100
Subject: [PATCH 2/2] Fix typings for is function

* The test parameter is optional.
* Add tests for the is function.
---
 index.d.ts            | 2 +-
 unist-util-is-test.ts | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index cd2ef07..01e9246 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -62,7 +62,7 @@ declare namespace unistUtilIs {
  */
 declare function unistUtilIs<T extends Node>(
   node: unknown,
-  test: unistUtilIs.Test<T> | Array<unistUtilIs.Test<any>>,
+  test?: unistUtilIs.Test<T> | Array<unistUtilIs.Test<any>>,
   index?: number,
   parent?: Parent,
   context?: any
diff --git a/unist-util-is-test.ts b/unist-util-is-test.ts
index 85c896e..ad4df30 100644
--- a/unist-util-is-test.ts
+++ b/unist-util-is-test.ts
@@ -1,5 +1,7 @@
 import {Node, Parent} from 'unist'
+
 import {Heading} from 'mdast'
+
 import unified = require('unified')
 import is = require('unist-util-is')
 import convert = require('unist-util-is/convert')
@@ -49,8 +51,6 @@ const maybeElement: Element = element
 is()
 // $ExpectError
 is<Node>()
-// $ExpectError
-is<Node>(heading)
 
 /*=== invalid generic ===*/
 // $ExpectError
@@ -63,6 +63,11 @@ is<{}>(heading, 'heading')
 /*=== assignable to boolean ===*/
 const wasItAHeading: boolean = is<Heading>(heading, 'heading')
 
+/*=== type Node test ===*/
+is<Node>(heading)
+is<Node>(heading, null)
+is<Node>(heading, undefined)
+
 /*=== type string test ===*/
 is<Heading>(heading, 'heading')
 is<Heading>(element, 'heading')