feat(breaking): toHaveTextContent supports nested arrays of sibling e…

…lements (testing-library#52)

BREAKING CHANGE: toHaveTextContent may produce more output in some cases due to including all nested sibling elements

README.md

@@ -243,7 +243,7 @@ expect(queryByTestId('button')).not.toHaveProp('title', 'ok');
 toHaveTextContent(text: string | RegExp, options?: { normalizeWhitespace: boolean });
 ```
 
-Check if an element has the supplied text.
+Check if an element or its children have the supplied text.
 
 This will perform a partial, case-sensitive match when a string match is provided. To perform a
 case-insensitive match, you can use a `RegExp` with the `/i` modifier.

src/__tests__/to-have-text-content.js

@@ -49,17 +49,27 @@ describe('.toHaveTextContent', () => {
 
   test('can handle multiple levels with content spread across descendants', () => {
     const { queryByTestId } = render(
-      <Text testID="parent">
-        <Text>Step</Text>
-        <Text> 1 </Text>
+      <View testID="parent">
+        <Text>One</Text>
+        <Text>Two</Text>
         <View>
-          <Text> of </Text>
+          <Text>Three</Text>
         </View>
-        4
-      </Text>,
+        <View>
+          <Text>Four</Text>
+          {null}
+          <Text>Five</Text>
+          <View>
+            <Text>Six</Text>
+            <Text>Seven</Text>
+          </View>
+          <Text>Eight</Text>
+        </View>
+        Nine
+      </View>,
     );
 
-    expect(queryByTestId('parent')).toHaveTextContent('Step 1 of 4');
+    expect(queryByTestId('parent')).toHaveTextContent('OneTwoThreeFourFiveSixSevenEightNine');
   });
 
   test('does not throw error with empty content', () => {

src/to-have-text-content.js

@@ -8,6 +8,8 @@ function getText(child, currentValue = '') {
 
   if (!child) {
     return value;
+  } else if (Array.isArray(child)) {
+    return child.reduce((acc, element) => acc + getText(path(['props', 'children'], element)), '');
   } else if (typeof child === 'object') {
     return getText(path(['props', 'children'], child), value);
   } else {