From db5ccb35d392a1de88c5f6e14f14a0cf36138398 Mon Sep 17 00:00:00 2001
From: Bruno Castro <bruno.castro@codeminer42.com>
Date: Sun, 26 Jul 2020 14:04:29 -0300
Subject: [PATCH] feat(toHaveStyle): handle when the prop style is undefined
 (#29)

---
 src/__tests__/to-have-style.js | 12 ++++++++++++
 src/to-have-style.js           |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/to-have-style.js b/src/__tests__/to-have-style.js
index 639f171..a179f94 100644
--- a/src/__tests__/to-have-style.js
+++ b/src/__tests__/to-have-style.js
@@ -36,4 +36,16 @@ describe('.toHaveStyle', () => {
     expect(() => expect(container).toHaveStyle({ fontWeight: 'bold' })).toThrowError();
     expect(() => expect(container).not.toHaveStyle({ color: 'black' })).toThrowError();
   });
+
+  test('handles when the style prop is undefined', () => {
+    const { getByTestId } = render(
+      <View testID="container">
+        <Text>Hello World</Text>
+      </View>,
+    );
+
+    const container = getByTestId('container');
+
+    expect(container).not.toHaveStyle({ fontWeight: 'bold' });
+  });
 });
diff --git a/src/to-have-style.js b/src/to-have-style.js
index f865365..4cd3e5b 100644
--- a/src/to-have-style.js
+++ b/src/to-have-style.js
@@ -38,7 +38,7 @@ function expectedDiff(expected, elementStyles) {
 export function toHaveStyle(element, style) {
   checkReactElement(element, toHaveStyle, this);
 
-  const elementStyle = element.props.style;
+  const elementStyle = element.props.style ?? {};
 
   const expected = Array.isArray(style) ? mergeAllStyles(style) : style;
   const received = Array.isArray(elementStyle) ? mergeAllStyles(elementStyle) : elementStyle;