swc-project/swc · error

Invalid JSON

Error message

Invalid JSON

What it means

Node binding panic in MinifyTarget::to_file: the JS side passed MinifyTarget::Json whose payload is not valid JSON for FxHashMap<String,String>, so serde_json::from_str failed and .expect aborted the process instead of returning a napi error.

Source

Thrown at bindings/binding_core_node/src/minify.rs:46

    input: Option<MinifyTarget>,
    options: String,
    extras: JsMinifyExtras,
}

enum MinifyTarget {
    /// Code to minify.
    Single(String),
    /// `FxHashMap<String, String>`
    Json(String),
}

impl MinifyTarget {
    fn to_file(&self, cm: Lrc<SourceMap>) -> Lrc<SourceFile> {
        match self {
            MinifyTarget::Single(code) => cm.new_source_file(FileName::Anon.into(), code.clone()),
            MinifyTarget::Json(json) => {
                let codes: FxHashMap<String, String> =
                    serde_json::from_str(json).expect("Invalid JSON");
                assert_eq!(
                    codes.len(),
                    1,
                    "swc.minify does not support concatting multiple files yet"
                );

                let (filename, code) = codes.iter().next().unwrap();

                cm.new_source_file(FileName::Real(filename.clone().into()).into(), code.clone())
            }
        }
    }
}

#[napi]
impl Task for MinifyTask {
    type JsValue = TransformOutput;
    type Output = TransformOutput;

View on GitHub (pinned to 5176682b65)

Solutions

1. Pass a JSON object mapping file names to code strings
2. Replace expect with proper error propagation so malformed JSON returns a catchable napi::Error

When it happens

Trigger: Thrown at bindings/binding_core_node/src/minify.rs:46 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of swc-project/swc@5176682b65 (2026-08-17). Data as JSON: /api/errors/e8724d8ebcd3ea9f. Report an issue: GitHub.