swc-project/swc · error

cannot process file because it's ignored by .swcrc

Error message

cannot process file because it's ignored by .swcrc

What it means

In Compiler::process_js_inner, config resolution returned None - which by contract means 'file should be ignored' - but processing continued to the point where a config is required, so swc bails with 'cannot process file because it's ignored by .swcrc'. A None result comes from the file matching an `exclude` pattern or matching no `test` pattern in the loaded config.

Source

Thrown at crates/swc/src/lib.rs:968

        P1: Pass,
        P2: Pass,
    {
        self.run(|| -> Result<_, Error> {
            let config = self.run(|| {
                self.parse_js_as_input(
                    fm.clone(),
                    program,
                    handler,
                    opts,
                    &fm.name,
                    Some(&comments),
                    |program| custom_before_pass(program),
                )
            })?;
            let config = match config {
                Some(v) => v,
                None => {
                    bail!("cannot process file because it's ignored by .swcrc")
                }
            };

            let after_pass = custom_after_pass(&config.program);

            let config = config.with_pass(|pass| (pass, after_pass));

            let orig = if config.source_maps.enabled() {
                self.get_orig_src_map(
                    &fm,
                    &config.input_source_map,
                    config
                        .comments
                        .get_trailing(config.program.span_hi())
                        .as_deref()
                        .unwrap_or_default(),
                    false,
                )?

View on GitHub (pinned to 5176682b65)

Solutions

1. Narrow the `exclude` regex (anchor it, make it path-aware) so intended files are not excluded
2. Extend `test` to cover the file's extension
3. Pre-filter input files (your own ignore logic) so ignored files never reach the compiler

Example fix

// before (.swcrc)
{ "exclude": "node_modules" }
// after (.swcrc)
{ "exclude": "(^|/)node_modules/" }

// JavaScript - apply your own exclude/test gate before compiling
const excluded = new RegExp(cfg.exclude ?? '$^'); // '$^' never matches
const tested = cfg.test ? new RegExp(cfg.test).test(file) : true;
if (!tested || excluded.test(file)) {
  console.warn(`skipping ${file} (not covered by .swcrc)`);
} else {
  await transformFile(file, options);
}

When it happens

Trigger: Feeding a file to the swc compiler (CLI or API) whose path hits an .swcrc `exclude` regex like "node_modules" or whose extension matches no `test`, without filtering it out beforehand.

Common situations: "exclude": ["node_modules"] also matching src/lib/node_modules-style paths; test patterns not covering .mjs/.cjs/.jsx; build scripts globbing directories broader than the config's intent.

Related errors

• .swcrc exists but not matched
• no config matched for file ({name})
• {} is not a valid expression
• Could not find .swcrc file while using rootMode "upward". Se
• The requested module '{specifier}' does not provide an expor

AI-assisted analysis of swc-project/swc@5176682b65 (2026-08-17). Data as JSON: /api/errors/f7822d69779ad2d0. Report an issue: GitHub.