Babel parses and removes sourceMappingURL from input

Bug Report

Current Behavior

I have some code that generates JavaScript files and includes the string //# sourceMappingURL=. Babel appears to remove this string and the remainder of the line before parsing.

Input Code

const comment = `//# sourceMappingURL=${path.basename(
  sourceMapFilename
)}`

Babel REPL

Output Code

const comment = `
  sourceMapFilename
)}`;

Expected behavior/code

//# sourceMappingURL= should not have special meaning inside of a template literal, and should be included in the generated output

const comment = `//# sourceMappingURL=${path.basename(sourceMapFilename)}`;

Babel Configuration (.babelrc, package.json, cli command)

None, see REPL link.

Environment

• Babel version(s): v7.4.2
• How you are using Babel: repl

[loganfsmyth]

@nicolo-ribaudo I think you misread this one. We’re removing the comment-like content of a JS string, which is not right.

The logic for stripping sourceMappingURL must not verify that it’s in a file-end comment token, and instead just look for the string itself.

@also Seems reasonable for us to fix this. For now I’d split the string into two pieces and concatenate with + so we don’t match the comment string, e.g.

const comment = `//# ` + `sourceMappingURL=${path.basename(

[nicolo-ribaudo]

It needs to be fixed in the convert-source-map package.