WorkerNavigator — Elide Docs

Elide implements the WinterCG Minimum Common API’s navigator surface — the WorkerNavigator interface together with its four mixin contracts (NavigatorID, NavigatorLanguage, NavigatorOnLine, NavigatorConcurrentHardware). A single immutable instance is exposed at globalThis.navigator and satisfies [SameObject] across reads.

Construction

WorkerNavigator is not constructible from JavaScript — both new WorkerNavigator() and plain-call WorkerNavigator() raise TypeError. The singleton is built once per realm during runtime initialisation and bound as a data property on globalThis.

Attributes

All attributes are readonly. Each value is computed once at runtime initialisation and never changes for the life of the realm.

Attribute	Type	Value
`appCodeName`	`string`	`"Mozilla"` (spec-mandated constant)
`appName`	`string`	`"Netscape"` (spec-mandated constant)
`product`	`string`	`"Gecko"` (spec-mandated constant)
`appVersion`	`string`	`5.0 (<platform> <arch>) Elide/<version>`
`userAgent`	`string`	`Mozilla/5.0 Elide/<version> (<platform> <arch>)`
`platform`	`string`	One of `linux`, `darwin`, `win32`, `freebsd`, `openbsd`, `sunos`, derived from `os.name`; `unknown` for unrecognised systems
`language`	`string`	Canonical BCP-47 form of the JVM default locale (e.g. `en-US`); falls back to `en-US` if the JVM reports an empty tag
`languages`	`FrozenArray<string>`	Frozen one-element array `[language]`. `[SameObject]` — identical reference on every read
`onLine`	`boolean`	`true` (HTML spec default for non-browser environments — Elide does not surface live network-state detection)
`hardwareConcurrency`	`number`	`Runtime.getRuntime().availableProcessors()`, never less than `1`

The architecture-segment of appVersion and userAgent (x64 / arm64 / ia32) mirrors the mapping used by process.arch, so values stay consistent across the Elide globals.

Notes on the implementation

languages is built as a frozen Array (Object.freeze) at navigator-creation time. The array is cached on the instance so every read returns the same reference, in line with the spec’s [SameObject] annotation. Mutation attempts on the array (languages[0] = ..., languages.push(...)) silently fail in sloppy mode and throw TypeError in strict mode.
onLine is currently a static true. The HTML spec describes it as “the user agent’s online state” — there is no portable cross-platform mechanism to surface that from a JVM process, and true is the documented default for environments that cannot answer the question.
The interface is exposed via globalThis.navigator, and the WorkerNavigator constructor is also installed as a global (globalThis.WorkerNavigator), so it is available for instanceof checks. It is not constructible, however — new WorkerNavigator() throws (see above).