From 40c05173a935a9ec319d95f0fad640c43db5e560 Mon Sep 17 00:00:00 2001
From: Ilya Moroz <37909603+ilyamore88@users.noreply.github.com>
Date: Thu, 13 Jan 2022 00:46:07 +0300
Subject: [PATCH] [Fix] isFunction function for async functions (#1857)

* fix test of async function, fix TS type because Function is banned type

* add tests for isFunction function

* fix eslint

* add changelog for 2.23.1

* fix changelog

* fix changelog
---
 docs/CHANGELOG.md                |  1 +
 src/components/utils.ts          |  4 +-
 test/cypress/tests/utils.spec.ts | 63 ++++++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+), 2 deletions(-)
 create mode 100644 test/cypress/tests/utils.spec.ts

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 52adf8fc..e9a4f930 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -20,6 +20,7 @@
 - `New` — `API` — The new `UiApi` section was added. It allows accessing some editor UI nodes and methods.
 - `Refactoring` — Toolbox became a standalone class instead of a Module. It can be accessed only through the Toolbar module.
 - `Refactoring` — CI flow optimized.
+- `Fix` - Recognize async `onPaste` handlers in tools [#1803](https://github.com/codex-team/editor.js/issues/1803).
 
 ### 2.22.3
 
diff --git a/src/components/utils.ts b/src/components/utils.ts
index 8b402bbf..e1e756f6 100644
--- a/src/components/utils.ts
+++ b/src/components/utils.ts
@@ -194,8 +194,8 @@ export function typeOf(object: any): string {
  * @returns {boolean}
  */
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export function isFunction(fn: any): fn is Function {
-  return typeOf(fn) === 'function';
+export function isFunction(fn: any): fn is (...args: any[]) => any {
+  return typeOf(fn) === 'function' || typeOf(fn) === 'asyncfunction';
 }
 
 /**
diff --git a/test/cypress/tests/utils.spec.ts b/test/cypress/tests/utils.spec.ts
new file mode 100644
index 00000000..bb0cb51a
--- /dev/null
+++ b/test/cypress/tests/utils.spec.ts
@@ -0,0 +1,63 @@
+/* eslint-disable @typescript-eslint/no-empty-function */
+import { isFunction } from '../../../src/components/utils';
+
+function syncFunction(): void {}
+
+async function asyncFunction(): Promise<void> {}
+
+const syncArrowFunction = (): void => {};
+
+const asyncArrowFunction = async (): Promise<void> => {};
+
+describe('isFunction function', () => {
+  it('should recognise sync functions', () => {
+    /**
+     * Act
+     */
+    const commonFunctionResult = isFunction(syncFunction);
+    const arrowFunctionResult = isFunction(syncArrowFunction);
+
+    /**
+     * Assert
+     */
+    expect(commonFunctionResult).to.eq(true);
+    expect(arrowFunctionResult).to.eq(true);
+  });
+
+  it('should recognise async functions', () => {
+    /**
+     * Act
+     */
+    const commonFunctionResult = isFunction(asyncFunction);
+    const arrowFunctionResult = isFunction(asyncArrowFunction);
+
+    /**
+     * Assert
+     */
+    expect(commonFunctionResult).to.eq(true);
+    expect(arrowFunctionResult).to.eq(true);
+  });
+
+  it('should return false if it isn\'t a function', () => {
+    /**
+     * Arrange
+     */
+    const obj = {};
+    const num = 123;
+    const str = '123';
+
+    /**
+     * Act
+     */
+    const objResult = isFunction(obj);
+    const numResult = isFunction(num);
+    const strResult = isFunction(str);
+
+    /**
+     * Assert
+     */
+    expect(objResult).to.eq(false);
+    expect(numResult).to.eq(false);
+    expect(strResult).to.eq(false);
+  });
+});