feat(toHaveStyle): handle when the prop style is undefined (#29)

testing-library · Jul 26, 2020 · db5ccb3 · db5ccb3
1 parent 60791a0
commit db5ccb3
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git 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
@@ -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;