JavaScript API - accent-sass

Published to npm as @zoosky/accent-sass, built with wasm-pack for the web target; see Install. The package ships an index.d.ts with real types.

Option names follow dart-sass's JavaScript API wherever the two have a name for the same knob, so a caller that knows one knows the other.

Exports

Export	Signature
`compileString`	`(source: string, options?: CompileOptions) => CompileResult`
`compile`	`(path: string, options?: CompileOptions) => CompileResult`
`from_string`	`(input: string) => string`
`default` / `initSync`	wasm-bindgen's initialisers

compile takes the entry point from options.files and ignores options.url, because the path already names the entry.

from_string is the package's original export, kept so existing callers keep working. It has no options and no filesystem, so it cannot resolve @use, and it throws the formatted error block as a string rather than an object.

`CompileOptions`

Option	Type	Default	Effect
`files`	`Record<string,string>` or `Map<string,string>`	`{}`	The stylesheet tree imports resolve against
`loadPaths`	`string[]`	`[]`	Searched when a relative import does not resolve
`url`	`string`	`"stdin"`	Virtual path of the source; relative imports resolve against its directory, and its extension sets the syntax
`style`	`"expanded"` \| `"compressed"`	`"expanded"`	Output style
`syntax`	`"scss"` \| `"indented"` \| `"css"`	from `url`	Syntax of the entry point only
`charset`	`boolean`	`true`	Emit `@charset` or a byte-order mark for non-ASCII output
`alertAscii`	`boolean`	`false`	Restrict error messages to ASCII. The inverse of the Rust API's `unicode_error_messages`
`quiet`	`boolean`	`false`	Silence `@warn` and `@debug`
`logger`	`(event: SassLogEvent) => void`	none	Called for each `@warn` and `@debug`

"sass" is accepted as a synonym for "indented", because that is what the file extension is called. dart-sass spells it indented.

Paths in files are virtual and normalized: a/b.scss and ./a/b.scss name the same file.

A malformed option throws a TypeError rather than failing later as a confusing Sass error. An array passed as files is rejected for that reason.

`CompileResult`

Field	Type	Meaning
`css`	`string`	The compiled CSS
`loadedUrls`	`string[]`	The files the compile read, in order

loadedUrls counts reads, not distinct files, so a stylesheet consulted twice appears twice. De-duplicate if you want a file count.

`SassLogEvent`

Field	Type
`type`	`"warn"` or `"debug"`
`message`	`string`
`file`	`string`
`line`	`number`, 1-based
`column`	`number`, 1-based

An exception thrown by the logger is swallowed: a warning must not be able to fail a compile that would otherwise have succeeded.

Errors

A failed compile throws a real Error, so instanceof Error holds and a stack trace survives.

Property	Meaning
`message`	The Sass message alone, with no span or source context
`formatted`	The full block the command line prints, with source line and caret
`file`	The file the error is in
`line`	1-based
`column`	1-based

A missing entry point or a non-UTF-8 file has no span; file is empty and line and column are 0, so a caller never has to branch on shape.

The synchronous filesystem

Fs::read returns bytes directly, with nothing to await. An importer therefore cannot fetch, cannot await and cannot use the File System Access API: every file a compile might touch must be in files before the call.

Making imports asynchronous would mean an asynchronous evaluator, which is a rewrite rather than a binding change.

Size

Build	wasm	gzipped
`--features wasm-exports,random`	1.72 MB	0.62 MB
Without `wasm-exports`	0.22 MB	—

The second row is a module with no compiler in it: without the feature, wasm-bindgen exports nothing and every symbol is dead code.