← back to v151 · prefetch-activation-beacon
conformance · v151
v151 · prefetch-activation-beacon — conformance probe
8 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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blocked
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| id | contract | kind | verdict | detail |
|---|---|---|---|---|
htmlscript-supports-is-static |
HTMLScriptElement.supports is a function — the STATIC feature-detection method on the interface object (never on script element instances), used to detect speculation rules support. spec ↗ | typeof | … | |
supports-not-on-script-instances |
The supports() static does not leak onto instances: a script element instance must not carry its own supports property (holds in any browser). spec ↗ | script | … | |
speculationrules-token-recognized |
HTMLScriptElement.supports('speculationrules') reports true — a prerequisite host for the proposal (legacy <link rel=prefetch> is a non-goal). This does not establish activation-beacon support. spec ↗ | script | … | |
deliverytype-on-navigation-prototype |
'deliveryType' is a member of PerformanceNavigationTiming.prototype — client evidence that a navigation was served from a prefetch ('navigational-prefetch'), not proof that the separate server-facing beacon fired. spec ↗ | script | … | |
deliverytype-not-static-on-constructor |
deliveryType is an instance attribute of navigation entries, never a static on the PerformanceNavigationTiming constructor (holds in any browser). spec ↗ | script | … | |
deliverytype-value-shape |
The current navigation entry's deliveryType is a string (possibly empty for a normal navigation) — an empty string is NOT an activation, and activation must never be inferred from request completion alone. spec ↗ | script | … | |
no-script-api-for-header |
The proposal defines no onPrefetchActivation member on Document or Navigator, and those common hosts expose none. This negative check does not prove that the HTTP-layer feature is implemented. spec ↗ | script | … | |
navigation-entry-host-present |
performance.getEntriesByType('navigation') returns an array — the PerformanceNavigationTiming host whose deliveryType the activation evidence lives on. spec ↗ | script | … |