Fixed #31

[Vessel9817]

Problem description

Suppose your project directory is C:\Users\username\myproject and the source map is trying to load index.js. After running the following snippet:

const filePath = `${process.cwd()}/${projectNameInput}/${source.substring(
  WEBPACK_SUBSTRING_INDEX,
)}`;

then filePath is set to C:\Users\username\myproject. This is because WEBPACK_SUBSTRING_INDEX is greater than the length of "index.js" (11 > 8), so source.substring(WEBPACK_SUBSTRING_INDEX) returns an empty string. In fact, WEBPACK_SUBSTRING_INDEX is completely arbitrary. The program continues as normal, expecting that filePath is a file path, and tries to write to said file. Except, it's a directory, so fs.writeFileSync fails:

Error: EISDIR: illegal operation on a directory, open 'C:\Users\username\myproject\

Changes

• Removed WEBPACK_SUBSTRING_INDEX and subsequent substring call
• Added error detection to fail with a clearer error message
• Updated dependency lock files*

*Note that I use npm rather than Yarn, so if the project runs without these changes, then feel free to discard this particular change.

Support

Versions tested:

• Node v24.0.0
• npm version 11.6.0