**1) Brief approach**I’d implement a prioritized locator pipeline: try primary locator, then iterate secondary locators ranked by confidence. If none match, optionally run fuzzy text matching constrained by DOM context and threshold. Each candidate returns a confidence score; we accept only candidates above an overall acceptance threshold and with additional validation checks to avoid false positives.**2) Example implementation (Python / Selenium)**python
from difflib import SequenceMatcher
from selenium.common.exceptions import NoSuchElementException
# locator = ("css", "button.save")
def fallback_find(driver, primary, secondaries, fuzzy_text=None,
accept_threshold=0.75, fuzzy_threshold=0.7):
def score_exact(el): return 1.0
def score_fuzzy(el, text):
sim = SequenceMatcher(None, el.text or "", text).ratio()
return sim
candidates = []
# try primary
try:
el = driver.find_element(*primary); candidates.append((el, score_exact(el)))
except NoSuchElementException: pass
# try secondaries
for loc, base_conf in secondaries:
try:
el = driver.find_element(*loc); candidates.append((el, base_conf))
except NoSuchElementException: pass
# fuzzy optional
if fuzzy_text:
# limit search scope to relevant containers or whole DOM if needed
elems = driver.find_elements_by_xpath("//*[string-length(normalize-space(text()))>0]")
for el in elems:
sim = score_fuzzy(el, fuzzy_text)
if sim >= fuzzy_threshold:
# combine with structural checks later
candidates.append((el, sim * 0.9))
# validate candidates: visibility, unique within scope, attribute checks
valid = []
for el, conf in candidates:
if not el.is_displayed(): continue
# avoid false positives: ensure attribute overlap with primary (id/class/tag)
attr_match = 0
if hasattr(el, "get_attribute"):
if primary[0] == "css":
# example heuristic: share a class or tag
if el.tag_name == driver.find_element(*primary).tag_name if False else True:
attr_match += 1
# final scoring
final_score = conf + 0.1 * attr_match
if final_score >= accept_threshold:
valid.append((el, final_score))
if not valid:
raise NoSuchElementException("No candidate passed validation")
# return highest scoring
return max(valid, key=lambda x: x[1])[0]
