Struct BundlerOptions 

pub struct BundlerOptions {
    pub alias: Vec<(String, PathBuf)>,
    pub virtual_modules: Vec<(String, String)>,
    pub conditions: Vec<String>,
    pub main_fields: Vec<String>,
    pub alias_fields: Vec<Vec<String>>,
    pub tsconfig: Option<PathBuf>,
    pub externals: Vec<String>,
}

How a bundle resolves: shim aliases, inline virtual modules, the module resolution controls and the tsconfig selection.

Fields

alias: Vec<(String, PathBuf)>

specifier -> absolute shim file path. The shim is bundled and transpiled like any other source (so .ts works) and lands in the source map, which keeps the disk-cache freshness check covering it.

virtual_modules: Vec<(String, String)>

specifier -> inline ES-module source (never touches the fs).

conditions: Vec<String>

Extra exports/imports condition names. The resolver appends these to its own base set, so an empty list resolves exactly as it did before any were configured.

main_fields: Vec<String>

package.json fields consulted when no exports entry matches. rolldown’s own default for a neutral platform is EMPTY, which leaves a plain "main": "index.js" package unresolvable; the default here is ["module", "main"].

alias_fields: Vec<Vec<String>>

package.json field paths holding a legacy path-remapping object.

tsconfig: Option<PathBuf>

The tsconfig whose paths / baseUrl govern resolution. None leaves rolldown’s per-module upward discovery in place; a value pins one file for the whole graph, which is the only way to select a config discovery would not find (tsconfig.test.json).

externals: Vec<String>

Specifiers to keep external beyond the registry’s own: a host that serves modules of its own at load time (a package’s bytecode already evaluated under a specifier) names them here so the chunk keeps the bare import instead of inlining a second copy.

Implementations

impl BundlerOptions

pub fn alias( self, specifier: impl Into<String>, target: impl AsRef<Path>, base: &Path, ) -> Self

Add a shim: specifier resolves to target, a file bundled and transpiled like any other source. A relative target is taken against base.

pub fn virtual_module( self, specifier: impl Into<String>, source: impl Into<String>, ) -> Self

Add an inline ES module under specifier.

pub fn with_tsconfig(self, tsconfig: Option<&str>, base: &Path) -> Self

Pin the tsconfig governing resolution, resolved against base when relative.

pub fn fingerprint(&self) -> u64

Stable content fingerprint, folded into every bundle cache key so editing an alias mapping, a virtual module’s source or a resolution control invalidates cached bytecode. (Alias target file content is already covered by the transitive input set; this covers the mapping itself, the inline sources, and every knob that changes output without changing a source byte. The tsconfig’s CONTENT is covered separately, through the bundle’s input set.)

Trait Implementations

impl Clone for BundlerOptions

fn clone(&self) -> BundlerOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BundlerOptions

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

Formats the value using the given formatter.

impl Default for BundlerOptions

fn default() -> Self

Returns the “default value” for a type.