[Bug] CSS Selector Syntax Not Validated - Invalid Selectors Cause Silent Failures

[anshul23102]

Description

CSS selector input from users is not validated. Invalid selectors silently fail to extract data with no error message. Users believe data was scraped when extraction silently failed.

Steps to Reproduce

1. User provides CSS selector: "div[class~=invalid" (missing bracket)
2. Scraper attempts to parse: $('div[class~=invalid')
3. Selector silently fails
4. Returns empty results
5. User assumes no data exists on page

Environment Information

• Framework: Cheerio/jsdom
• Input: CSS selector from user
• Validation: None
• Application version: Current main branch

Expected Behavior

CSS selectors validated before use. Invalid selectors rejected with clear error message. User can correct and retry.

Actual Behavior

File: src/services/scraper.js
Uses user selector without validation: $(userSelector)

Code Reference

File: src/services/scraper.js
Missing: CSS selector validation

Additional Context

Validate selectors:

try {
  cheerio.parseSelector(userSelector);
} catch (e) {
  return error('Invalid CSS selector');
}

GSSoC Points Estimate: Level 1 (Bug/Validation)

Suggested Labels

• gssoc:approved
• type:bug
• severity:medium
• area:validation

[Xenon010101]

Hi, I am a GSSoC 2026 contributor and would like to work on this issue. This project matches my expertise. Please assign it to me.

/assign

[garima-agarwall]

Hi @sharmavaibhav31
I would like to work on this issue. Please assign this to me if possible.