🧩 Summary

When formatting a JavaScript file using prettier-plugin-jsdoc with Prettier v3.6.0, the plugin crashes with:

TypeError: Cannot read properties of undefined (reading 'length')

This happens on every format attempt in a valid project with no syntax errors.

🧪 Environment

Node.js: 24.1.0
Prettier: 3.6.0
prettier-plugin-jsdoc: 1.3.2
prettier-plugin-organize-imports: 4.1.0
VS Code: v1.100.0 (Auto-format on save enabled)
OS: Linux 6.12.28-1-MANJARO (x64)

🧾 .prettierrc

{
  "$schema": "https://json.schemastore.org/prettierrc.json",
  "plugins": ["prettier-plugin-organize-imports", "prettier-plugin-jsdoc"]
}

🧱 Prettier Output Log (Redacted)

[INFO] Formatting file:///.../src/utility.js
[INFO] Using config file at .../.prettierrc
[INFO] PrettierInstance: { version: "3.6.0" }
[INFO] Prettier Options:
{
  "filepath": ".../src/utility.js",
  "parser": "babel",
  "plugins": [
    ".../node_modules/prettier-plugin-organize-imports/index.js",
    ".../node_modules/prettier-plugin-jsdoc/dist/index.js"
  ]
}
[ERROR] Error formatting document.
[ERROR] Cannot read properties of undefined (reading 'length')
TypeError: Cannot read properties of undefined (reading 'length')
    at norm (.../node_modules/binary-searching/search-bounds.js:93:27)
    at Object.eq (.../node_modules/binary-searching/search-bounds.js:119:12)
    at findTokenIndex (.../prettier-plugin-jsdoc/dist/utils.js:115:20)
    at .../prettier-plugin-jsdoc/dist/parser.js:21:28
    at Array.map (<anonymous>)
    at Object.jsdocParser [as parse] (.../prettier-plugin-jsdoc/dist/parser.js:18:36)

✅ Steps to Reproduce

1. Use Prettier 3.6.0 with the .prettierrc config above.

2. Enable prettier-plugin-jsdoc.

3. Save any valid .js file with a JSDoc comment.

4. Observe crash.

✅ Expected Behavior

The plugin should not crash. File should be formatted or skipped gracefully.

🩹 Workaround

Downgrading to [email protected] resolves the issue:

npm install [email protected] --save-dev

📌 Notes

Looks like the bug might be due to findTokenIndex() receiving an unexpected undefined, possibly due to changes in the Prettier parser API in 3.6.0.

Let me know if a minimal reproducible repo would help — happy to provide one.

Thanks for your work on this plugin!