bug (maybe?): `data` not inheriting

[Zearin]

NOTE: For future readers unfamiliar with my recent activity in this repo: The attached test files (below) are an attempt by me to learn hTest by rewriting some of the Web Platform Tests for DOMRect and DOMRectReadOnly in hTest format. @LeaVerou helped me several times when I was struggling to make my brain rewire its thinking from the standard Node.js TestRunner (or Mocha) test format to hTest format.

---

Using the following test files:

• 📄 index.html
• 📄 DOMRect-001-issue.js
  • (For reference, the above test was written thanks to this reply by LeaVerou)

I’m getting the following error:

Unhandled Promise Rejection: TypeError: undefined is not an object (evaluating 'this.data.r.x = 5')

Version info:

• macOS Tahoe (26.2)
• Safari 26.2 (21623.1.14.11.9)
• hTest 0.0.20

[LeaVerou]

Well, that sucks. I do think it's an easy fix though. @DmitrySharabin we should use Object.create() with the parent object as the protoype, that way we automatically get changes to inherited properties without having to copy them.

[DmitrySharabin]

I do think it's an easy fix though. @DmitrySharabin we should use Object.create() with the parent object as the protoype, that way we automatically get changes to inherited properties without having to copy them.

We actually already have that, if I don't miss anything:

htest/src/classes/Test.js

Line 26 in 7a59f66

this.data = Object.assign({}, this.parent?.data, this.data);

Hm. There must be something else then. 🤔 Investigating.

[DmitrySharabin]

I think I know why it happens.

When we create tests, the parent data object is an empty object (L10 in DOMRect-001-issue.js). So, there are no properties we can copy as references to the child tests. We modify the data object in the beforeAll() hook (L8 in DOMRect-001-issue.js). By the time we do it, all child tests data objects are defined and have no references to the properties we set in the parent's data object on the tests run.

To fix it, we should define the data object with all the props we'd like to inherit beforehand: data: { r: new DOMRect() } (in that case, we don't need to set it in the beforeAll() hook). If we do that, we'll get what we actually need—the data object is correctly inherited.

[DmitrySharabin]

There are some issues with the nested width tests. But it seems orthogonal to this issue. I'll let you know if I find out what exactly doesn't work there, though.

[Zearin]

@DmitrySharabin Thank you! 🙏🏽 These are good lessons.

[DmitrySharabin]

@DmitrySharabin Thank you! 🙏🏽 These are good lessons.

@Zearin, you are more than welcome! I'm glad you're giving hTest a try. It's worth more attention and love. 😊

[DmitrySharabin]

Speaking of the width tests. It's not an issue with tests, but rather with how we render nested tests. It seems like hTest doesn't support more than one level of nesting:

htest/src/render.js

Lines 24 to 25 in 7a59f66

	root.tests?.map?.(t => {
	let tests = t.isGroup ? t.tests : [t];

It leads to errors in the console with the test rendered as if it's still being evaluated:

@LeaVerou, not sure what's the best way to handle such cases without manually rewriting tests so they are not that deeply nested. 🤔

[LeaVerou]

That’s only the html ui. And yes, it’s a known tbd that it should support more levels of nesting.