Debugging and Recovery Under Pressure Questions

func Handle(w http.ResponseWriter, r *http.Request){
  if isOldClient(r){
    body := parseJSON(r.Body)
    newBody, err := transformRequest(body)
    if err!=nil { respond400(w, err); return }
    if !validate(newBody, newSchema){ respond500(w,"validation"); return }
    r.Body = marshal(newBody)
  }
  resp := forwardToService(r)
  if isOldClient(r){
    resp.Body = transformResponse(resp.Body)
  }
  copyResponse(w, resp)
}

#!/bin/bash
log=/var/log/myapp.log
pidfile=/var/run/myapp.pid
ts=$(date +%Y%m%d%H%M%S)
rot="${log}.${ts}"

# 1. ensure same fs (optional)
# mv is atomic only on same fs
mv "$log" "$rot" || { echo "mv failed (cross-fs?)"; exit 1; }

# 2. create fresh file with same perms/owner
touch "$log"
chmod --reference="$rot" "$log" 2>/dev/null || true
chown --reference="$rot" "$log" 2>/dev/null || true

# 3. signal process to reopen
if [ -f "$pidfile" ]; then
  kill -HUP $(cat "$pidfile") || echo "signal failed"
fi

# 4. optional: wait until no process holds $rot (lsof) then compress
while lsof +f -- "$rot" >/dev/null 2>&1; do sleep 1; done
gzip "$rot"

import random
import pytest

def test_empty_input():
    arr = []
    with pytest.raises(IndexError):
        find_kth_smallest(arr, 1)
# Expected: IndexError. Catches failure to validate input length / off-by-one when array is empty.

def test_single_element_k1():
    arr = [42]
    assert find_kth_smallest(arr, 1) == 42
# Expected: 42. Catches wrong handling of base cases or assuming length>1.

def test_duplicates():
    arr = [5, 1, 5, 3, 5]
    # sorted = [1,3,5,5,5]; 3rd smallest is 5
    assert find_kth_smallest(arr, 3) == 5
# Expected: 5. Catches incorrect deduplication or using set() accidentally.

def test_k_out_of_range_too_small():
    arr = [1,2,3]
    with pytest.raises(IndexError):
        find_kth_smallest(arr, 0)
# Expected: IndexError. Catches off-by-one (1-index vs 0-index) mistakes.

def test_k_out_of_range_too_large():
    arr = [1,2,3]
    with pytest.raises(IndexError):
        find_kth_smallest(arr, 4)
# Expected: IndexError. Catches missing bounds checks.

def test_k_equals_length():
    arr = [7,2,9,4]
    # largest element when k == len(arr)
    assert find_kth_smallest(arr, len(arr)) == max(arr)
# Expected: max(arr). Catches incorrect assumptions about k range or reversed ordering.

def test_large_input_randomized():
    n = 10000
    arr = [random.randint(0, 100000) for _ in range(n)]
    k = 5000
    expected = sorted(arr)[k-1]
    assert find_kth_smallest(list(arr), k) == expected
# Expected: matches sorted result. Detects performance regressions or incorrect algorithms that fail at scale.