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conformance · v150
v150 · speculative-load-measurement — conformance probe
7 assertions drawn from the spec. Each is a single contract the spec text makes. Pass/fail reflects what this browser executed; blocked means the contract was not run because it needs user mediation, hardware, or another unavailable precondition. Open the page in Chrome stable / canary / Firefox / Safari to compare.
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pass
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fail
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| id | contract | kind | verdict | detail |
|---|---|---|---|---|
performance-object-exists |
window.performance exists — the host object the proposed getSpeculations() instance method hangs off. spec ↗ | exists | … | |
getspeculations-instance-method |
performance.getSpeculations is a function — an INSTANCE method on the performance object (never a static on the Performance constructor), exposed when the SpeculationMeasurement runtime feature is on. spec ↗ | typeof | … | |
not-a-static-on-constructor |
The surface is not a static on the Performance constructor — Performance.getSpeculations must not exist as a function (the binding is the instance object, per the experimental Chromium IDL). spec ↗ | script | … | |
stale-property-form-absent |
The current explainer/IDL surface is a method, not the stale performance.speculations property name retained in some trial metadata; that property must be undefined. spec ↗ | script | … | |
returns-speculationdata-shape |
When exposed, getSpeculations() returns an object whose preloads, preconnects and navigations members are arrays and which carries the navigationDestinationURL member (USVString?, so it may be null). spec ↗ | script | … | |
destination-null-not-undefined |
When exposed, navigationDestinationURL is either a string (a same-origin destination) or null — the nullable USVString's JS absence value is null, never undefined (exposure shape itself is provisional in the explainer). spec ↗ | script | … | |
preload-used-field-shape |
When exposed, every reported preload entry has a string url and a used value that is either null (not consumed at read time) or a number (DOMHighResTimeStamp of consumption). Null is only definitive waste when the page lifetime ends; pagehide may instead enter the BFCache. spec ↗ | script | … |