pi-lens/rules/tree-sitter-queries/typescript-disabled/empty-catch.yml

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# Empty Catch Block
# Detects catch blocks that silently swallow errors
id: empty-catch
name: Empty Catch Block
severity: error
category: reliability
defect_class: silent-error
inline_tier: blocking
language: typescript

message: "Empty catch block — properly handle or log the error"

description: |
  Silently swallowing errors makes debugging impossible.
  
  ✅ PROPER FIXES (choose one):
  1. Log the error: console.error(`[context] Failed to X:`, err)
  2. Rethrow if can't handle: throw err
  3. Return a safe default: return null / return [] / return defaultValue
  4. Handle specific errors: if (err.code === 'ENOENT') { ... }
  5. Propagate to caller: callback(err) / reject(err)
  
  ❌ NOT ACCEPTABLE:
  - void err; (just references variable, does nothing)
  - /* ignored */ comments without action
  - console.log without the error object

query: |
  (catch_clause
    (identifier) @ERR
    (statement_block) @BODY)

# Post-filter: Check if body is effectively empty (ignoring comments)
post_filter: empty_body

# Capture metavariables
metavars:
  - ERR      # The error parameter name
  - BODY     # The catch block body

# Additional metadata
tags:
  - security
  - debugging
  - reliability
  - best-practice

# Examples for documentation
examples:
  bad: |
    try {
      await fetch('/api');
    } catch (err) {
      // Empty - BAD!
    }
  
  good: |
    try {
      await fetch('/api');
    } catch (err) {
      console.error('[API] Fetch failed:', err);
      throw err; // or return safe default
    }

# Auto-fix available
has_fix: false