Proposal to Remove the Test

Oct 13, 2025 by wbrum.org 146 views

Removing Unrelated Tests from Interop-2025: A Case Study on Zoom Property Interoperability

Introduction

The web is a complex and ever-evolving platform, with new features and technologies being introduced regularly. As a result, ensuring interoperability between different browsers and devices has become a crucial aspect of web development. The Web Platform Tests (WPT) project plays a vital role in this process by providing a comprehensive set of tests to ensure that web browsers behave consistently and correctly. However, with the vast number of tests available, it's not uncommon for unrelated or unnecessary tests to be included in the interop-2025 focus area. In this article, we'll explore the case of the zoom-with-sign-function.html test and why it's proposed to be removed from interop-2025.

Test List

The zoom-with-sign-function.html test is currently included in the interop-2025 "webcompat" focus area as part of support for the "zoom" property. However, a closer examination of the test reveals that it's actually testing a largely unrelated thing, using the zoom property as a means to do so. This test is designed to check whether sign(1em - 1px) parses and computes as expected, which has some subtlety to it. As discussed in the GitHub issue https://github.com/web-platform-tests/interop/issues/867#issuecomment-2451975521, this syntax has been proposed as part of a focus area and was rejected.

Rationale

The proposal to remove this test from interop-2025 is based on the fact that it doesn't make sense to consider zoom interoperability as depending on how calc(sign(1em - 1px)...) behaves. This test is essentially testing a specific parsing scenario that's not directly related to the zoom property. As a result, it's not providing any meaningful value to the interop-2025 focus area.

Current State of Interop-2025

Currently, Firefox rejects this syntax and fails the WPT test as a result. However, this doesn't necessarily mean that the test is essential to the interop-2025 focus area. In fact, there's a different WPT test that's included in interop-2025, which also has test coverage for various zoom parsing scenarios. This test is more relevant to the zoom property and provides a more comprehensive understanding of its behavior.

Proposal to Remove the Test

Based on the above analysis, it's proposed to remove the zoom-with-sign-function.html test from interop-2025. This test is not providing any meaningful value to the focus area and is essentially testing a specific parsing scenario that's not directly related to the zoom property. By removing this test, we can ensure that the interop-2025 focus area remains focused on the essential aspects of web compatibility and interoperability.

Conclusion

Ensuring interoperability between different browsers and devices is a complex task that requires a comprehensive set of tests. However, with the vast number of tests available, it's not uncommon for unrelated or unnecessary tests to be included in the interop-2025 focus area. The case of the zoom-with-sign-function.html test is a prime example of this. By removing this test, we can ensure that the interop-2025 focus area remains focused on the essential aspects of web compatibility and interoperability.

Related Issues

https://github.com/web-platform-tests/interop/issues/825 - Proposed addition of the "zoom" property to interop-2025
https://github.com/web-platform-tests/interop/issues/867#issuecomment-2451975521 - Discussion on the subtlety of the sign(1em - 1px) syntax
https://github.com/web-platform-tests/interop/issues/937 - Proposal to split out similar bits from the zoom test, leaving behind simpler calc(...sign(...)) expressions that do work interoperably.

Future Work

Review and refine the interop-2025 focus area to ensure that it remains focused on the essential aspects of web compatibility and interoperability.
Continue to monitor and address any issues related to the zoom property and its parsing scenarios.
Explore ways to improve the test coverage for the zoom property and its related parsing scenarios.
Q&A: Removing Unrelated Tests from Interop-2025

Introduction

In our previous article, we explored the case of the zoom-with-sign-function.html test and why it's proposed to be removed from interop-2025. In this article, we'll answer some frequently asked questions related to this topic.

Q: What is interop-2025 and why is it important?

A: Interop-2025 is a focus area within the Web Platform Tests (WPT) project that aims to ensure interoperability between different browsers and devices. It's essential for web developers to ensure that their websites and applications work consistently across different browsers and devices.

Q: Why is the `zoom-with-sign-function.html` test being removed from interop-2025?

A: The zoom-with-sign-function.html test is being removed because it's not providing any meaningful value to the interop-2025 focus area. It's essentially testing a specific parsing scenario that's not directly related to the zoom property.

Q: What's the difference between the `zoom-with-sign-function.html` test and the other `zoom` test in interop-2025?

A: The zoom-with-sign-function.html test is testing a specific parsing scenario that's not directly related to the zoom property. The other zoom test in interop-2025, on the other hand, provides a more comprehensive understanding of the zoom property and its behavior.

Q: Why is it important to remove unnecessary tests from interop-2025?

A: Removing unnecessary tests from interop-2025 helps to ensure that the focus area remains focused on the essential aspects of web compatibility and interoperability. It also helps to reduce the complexity of the test suite and makes it easier to maintain.

Q: What's the impact of removing the `zoom-with-sign-function.html` test on web developers?

A: The removal of the zoom-with-sign-function.html test will not have any significant impact on web developers. The other zoom test in interop-2025 will continue to provide a comprehensive understanding of the zoom property and its behavior.

Q: How can web developers contribute to the interop-2025 focus area?

A: Web developers can contribute to the interop-2025 focus area by:

Reporting issues and bugs related to web compatibility and interoperability
Participating in the discussion and review of test cases
Helping to maintain and update the test suite
Providing feedback and suggestions on how to improve the focus area

Q: What's the next step for the `zoom-with-sign-function.html` test?

A: The zoom-with-sign-function.html test will be removed from interop-2025 and will no longer be maintained or updated. However, the other zoom test in interop-2025 will continue to provide a comprehensive understanding of the zoom property and its behavior.

Q: How can I stay up-to-date with the latest developments on interop-2025?

A: You can stay up-to-date with the latest developments on interop-2025 by:

Following the Web Platform Tests (WPT) project on GitHub
Participating in the discussion and review of test cases
Attending web development conferences and meetups
Reading web development blogs and articles

Conclusion

Removing unnecessary tests from interop-2025 is an important step in ensuring that the focus area remains focused on the essential aspects of web compatibility and interoperability. By answering these frequently asked questions, we hope to provide more clarity on this topic and encourage web developers to contribute to the interop-2025 focus area.