Struct WorkerScriptLoader 

pub struct WorkerScriptLoader {
    pub source: WorkerScriptSource,
    pub script_type: WorkerScriptType,
}

Worker script loader — handles URL-based script fetching for Workers.

Provides the bridge between bao_browser’s Worker tracking and the script loading process described in DF-WK-2. In browser mode, servo’s DOM Worker binding handles the full script loading pipeline internally. This struct provides the bao_browser-side tracking and validation that supplements servo’s internal mechanism.

For Workers created via bao_engine::WebWorker (CLI/test mode), this loader resolves script URLs and provides script content for evaluation on the Worker thread.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

Fields

source: WorkerScriptSource

The script URL or inline source to load. @trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

script_type: WorkerScriptType

The script type (Classic or Module). @trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

Implementations

impl WorkerScriptLoader

pub fn inline(script: String, script_type: WorkerScriptType) -> Self

Create a new WorkerScriptLoader for an inline script source.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn url(url: String, script_type: WorkerScriptType) -> Self

Create a new WorkerScriptLoader for a URL-based script.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn from_source( source: WorkerScriptSource, script_type: WorkerScriptType, ) -> Self

Create from WorkerScriptSource.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn resolve(&self) -> Result<WorkerScriptSource, WorkerScriptLoadError>

Resolve the script source to loadable content.

For inline sources, returns the content directly. For URL sources, resolves the URL to determine the script location. In browser mode, servo handles the actual HTTP fetch internally — this method validates the URL and returns it for servo to fetch. For data:/blob: URLs embedded in the WorkerScriptSource::Inline variant, the content is already available.

Returns the script content (for inline) or the validated URL (for URL source).

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn validate_mime_type( mime_type: &str, url: &str, ) -> Result<(), WorkerScriptLoadError>

Validate the MIME type of a Worker script response.

Per DF-WK-2: “JS MIME 校验” — HTTP responses for Worker scripts must have a JavaScript MIME type. This validation applies to HTTP responses only (not data: or blob: URLs).

Returns Ok(()) if the MIME type is valid, or Err with the invalid MIME type details.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn script_url(&self) -> Option<&str>

Returns the script URL for this loader (if URL-based).

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn requires_fetch(&self) -> bool

Returns true if this loader requires a network fetch.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn load<F>( &self, stealth_profile: &Option<StealthProfile>, state_callback: F, ) -> Result<WorkerScriptLoadResult, WorkerScriptLoadError>

where F: FnMut(WorkerScriptLoadState),

Load the Worker script through the full DF-WK-2 pipeline.

This method implements the complete Worker script loading pipeline:

1. Resolve — URL parsing / data: / file: extraction
2. Fetch — HTTP GET via bao_runtime’s stealth HTTP client
3. Validate — MIME type check (JS MIME types only)
4. Decode — UTF-8 decode of response body
5. Compile — SpiderMonkey compilation (Classic vs Module)
6. Ready — script source available for evaluation

For inline/data:/file: sources, steps 2–4 are skipped — content is already available as a UTF-8 string.

The stealth_profile is passed through to the HTTP client so that Worker script fetches use the same TLS/HTTP2 fingerprint as the parent page (SPEC criterion #12: CRIT-STL-WK).

The state_callback is called at each pipeline stage transition, enabling CDP observability of the loading progress.

Returns WorkerScriptLoadResult on success, or WorkerScriptLoadError at the stage where loading failed.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2] pipeline: fetch → MIME check → decode → compile @trace REQ-BRW-004 [criterion:12] CRIT-STL-WK: Worker fetch uses parent page’s stealth TLS/HTTP2 profile

pub fn load_simple( &self, stealth_profile: &Option<StealthProfile>, ) -> Result<WorkerScriptLoadResult, WorkerScriptLoadError>

Load the Worker script without state callbacks (simplified API).

Equivalent to load() with a no-op state callback. Use when CDP observability of loading stages is not needed.

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

pub fn is_module(&self) -> bool

Returns the script type for SpiderMonkey compilation options.

Module Workers use ES module compilation; Classic Workers use the default script compilation (DF-WK-2: “Classic/Module 编译”).

@trace REQ-BRW-004 [entity:Worker] [DF-WK-2]

Trait Implementations

impl Clone for WorkerScriptLoader

fn clone(&self) -> WorkerScriptLoader

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WorkerScriptLoader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.