build_fingerprint_js (fingerprint_builder)

Assembles a complete JavaScript injection script that overrides browser fingerprint surfaces CDP cannot control, using a shared native-toString hook and per-section builders.

def build_fingerprint_js(
    config: FingerprintConfig, user_agent: str = '', platform: str = ''
) -> str:
    """Build the complete page fingerprint injection script.

    Returns a single JS string that installs the shared native-toString hook
    and overrides every configured fingerprint surface CDP cannot handle.
    Empty string if nothing to inject.

    Args:
        config: Fingerprint configuration.
        user_agent: Reduced User-Agent string to expose as ``navigator.userAgent``
            in every realm (including detached iframes). Empty string skips it.
        platform: ``navigator.platform`` value to expose in every realm.
    """
    parts: list[str] = [_build_identity_js(user_agent, platform)]

    if 'navigator' in config:
        nav: dict[str, object] = dict(config[

... (truncated -- full source via MCP)