Contact emails
owner.one@example.com, owner.two@example.com
Explainer
https://example.com/explainer.md
https://example.com/explainer_slides.pdf
Specification
https://w3c.github.io/test-feature-spec/
Design docs
https://developer.chrome.com/docs/test-feature/
Summary
This is a detailed summary of the test feature being created. It is designed to populate every possible field for testing purposes.
Blink component
Blink>TestBlink>Internals>Test
Web Feature ID
test-feature-ndb-constructor
Search tags
test, example, constructor
TAG review
https://github.com/w3ctag/design-reviews/issues/999
TAG review status
Pending
Origin Trial Name
Test 123
Goals for experimentation
None
Risks
Interoperability and Compatibility
Low risk. The API surface is small and unlikely to conflict with other browser implementations.
Gecko: In development (
https://github.com/mozilla/standards-positions/issues/999) Has expressed cautious optimism.
WebKit: Positive (
https://lists.webkit.org/pipermail/webkit-dev/2025-October/subject.html) Has raised concerns about potential privacy implications.
Web developers: Strongly positive (
https://developer.chrome.com/blog/test-feature-coming-soon/) Positive feedback received from the web developer community via social media.
Other signals: No signals from other implementers at this time.
Ergonomics
The API could be complex for new developers, but documentation should mitigate this.
Activation
There are minimal activation risks, primarily related to experimental flag interactions.
Security
The main security risk involves ensuring that data is properly sanitized.
WebView application risks
Does this intent deprecate or change behavior of existing APIs,
such that it has potentially high risk for Android WebView-based
applications?
No specific WebView risks have been identified.
Ongoing technical constraints
This feature is only available in secure contexts (HTTPS).
Debuggability
The feature is fully debuggable via Chrome DevTools, with a dedicated panel.
Will this feature be supported on all six Blink platforms
(Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?
Yes
This feature is expected to work on all desktop and mobile platforms.
Yes
A full suite of Web Platform Tests (WPT) will be developed and upstreamed.
DevTrial instructions
To test, navigate to chrome://flags and enable #enable-test-feature-constructor.
Flag name on about://flags
enable-test-feature-constructor
Finch feature name
TestFeatureConstructorStudy
Non-finch justification
This feature is not suitable for a Finch experiment due to its nature.
Requires code in //chrome?
False
Tracking bug
https://bugs.chromium.org/p/chromium/issues/detail?id=12345
Launch bug
https://buganizer.corp.google.com/issues/67890
Measurement
Usage will be measured via a UMA histogram named "Test.Feature.Constructor.Usage".
Availability expectation
Expected to be available in developer channels by M132.
Adoption expectation
We expect 100% adoption within our test suites.
Adoption plan
No external adoption plan is necessary as this is for testing.
Non-OSS dependencies
Does the feature depend on any code or APIs outside the Chromium
open source repository and its open-source dependencies to
function?
There are no non-Open-Source dependencies.
Estimated milestones
No milestones specified
Anticipated spec changes
Open questions about a feature may be a source of future web compat or
interop issues. Please list open issues (e.g. links to known github
issues in the project for the feature specification) whose resolution
may introduce web compat/interop risk (e.g., changing to naming or
structure of the API in a non-backward-compatible way).
We anticipate minor changes to the spec based on implementer feedback.
Link to entry on the Local testing
http://localhost/feature/234?gate=101
Links to previous Intent discussions
Intent to Ship: https://example.com/ship