fix(pretty-format): handle tagName not being a string (#10397)

jestjs · Aug 12, 2020 · cf07d11 · cf07d11
1 parent 80985ed
commit cf07d11
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Showing 3 changed files with 24 additions and 2 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 ### Fixes
 
+- `[pretty-format]` Handle `tagName` not being a string ([#10397](https://github.com/facebook/jest/pull/10397))
+
 ### Chore & Maintenance
 
 ### Performance

diff --git a/packages/pretty-format/src/__tests__/DOMElement.test.ts b/packages/pretty-format/src/__tests__/DOMElement.test.ts
@@ -564,4 +564,22 @@ Testing.`;
       {maxDepth: 2},
     );
   });
+
+  it('handles `tagName` not being a string', () => {
+    expect({
+      name: 'value',
+      tagName: {text: 'param'},
+      type: 'string',
+    }).toPrettyPrintTo(
+      [
+        'Object {',
+        '  "name": "value",',
+        '  "tagName": Object {',
+        '    "text": "param",',
+        '  },',
+        '  "type": "string",',
+        '}',
+      ].join('\n'),
+    );
+  });
 });
diff --git a/packages/pretty-format/src/plugins/DOMElement.ts b/packages/pretty-format/src/plugins/DOMElement.ts
@@ -25,8 +25,10 @@ const ELEMENT_REGEXP = /^((HTML|SVG)\w*)?Element$/;
 
 const testNode = (val: any) => {
   const constructorName = val.constructor.name;
-  const {nodeType, tagName = ''} = val;
-  const isCustomElement = tagName.includes('-') || val.hasAttribute?.('is');
+  const {nodeType, tagName} = val;
+  const isCustomElement =
+    (typeof tagName === 'string' && tagName.includes('-')) ||
+    val.hasAttribute?.('is');
 
   return (
     (nodeType === ELEMENT_NODE &&