crash when compiling empty or type-only file with sourcemaps

[jbedard]

Describe the bug

A panic occurs when generating source-maps for an empty or types-only file. Seems to only happen with the binary and not the npm cli.

See the line it crashes on. Note the version of sourcemap is not the latest.

Type-only fails with commonjs modules and sourcemaps enabled:
swcrc.json:

{
  "module": {
    "type": "commonjs"
  },
  "jsc": {
    "parser": {
      "syntax": "typescript"
    }
  }
}

> echo "export type Foo = number" > b.ts
> swc-darwin-x64 compile --source-file-name b.ts --config-file swcrc.json --source-maps true --out-file b.js b.ts
thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', /Users/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sourcemap-6.2.3/src/types.rs:655:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Empty fails without any swcrc:

> echo '' > d.ts
> ./swc-darwin-x64 compile --source-file-name d.ts --source-maps true --out-file d.js d.ts
thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', /Users/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sourcemap-6.2.3/src/types.rs:655:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Input code

export type Foo = number

Config

{
  "module": {
    "type": "commonjs"
  },
  "jsc": {
    "parser": {
      "syntax": "typescript"
    }
  }
}

Playground link

No response

Expected behavior

Output an empty file + sourcemap

Actual behavior

No response

Version

SWC 0.91.63 (from v1.3.77)

Additional context

No response

[supercairos]

I have the same issue :(

[Zemnmez]

I have found a workaround to this issue: putting a single comment in the file fixes it, assumedly because it makes the JS file length nonzero.

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.