### Question:
AccountTelemetryService { void validateAnonymizationRules(AccountTelemetry telemetry) { Optional.ofNullable(telemetry.getRules()).orElse(new ArrayList<>()) .forEach(rule -> { String decodedRule = new String(Base64.getDecoder().decode(rule.getValue().getBytes())); createAndCheckPattern(decodedRule); }); } AccountTelemetryService(AccountTelemetryRepository accountTelemetryRepository); AccountTelemetry create(AccountTelemetry telemetry, String accountId); AccountTelemetry getOrDefault(String accountId); Features updateFeatures(String accountId, Features newFeatures); AccountTelemetry createDefaultAccuontTelemetry(); String testRulePatterns(List<AnonymizationRule> rules, String input);  }### Answer:
@Test public void testValidateRules() { AccountTelemetry telemetry = new AccountTelemetry(); List<AnonymizationRule> rules = new ArrayList<>(); AnonymizationRule rule = new AnonymizationRule(); rule.setReplacement("[REDACTED]"); String pattern = "\\d{4}[^\\w]\\d{4}[^\\w]\\d{4}[^\\w]\\d{4}"; String encodedPattern = new String(Base64.getEncoder().encode(pattern.getBytes())); rule.setValue(encodedPattern); rules.add(rule); telemetry.setRules(rules); underTest.validateAnonymizationRules(telemetry); }
@Test public void testValidateRulesWithoutRules() { AccountTelemetry telemetry = new AccountTelemetry(); underTest.validateAnonymizationRules(telemetry); }
@Test public void testValidateRulesWithInvalidRules() { AccountTelemetry telemetry = new AccountTelemetry(); List<AnonymizationRule> rules = new ArrayList<>(); AnonymizationRule rule = new AnonymizationRule(); rule.setReplacement("[REDACTED]"); String pattern = "invalidrule{"; String encodedPattern = new String(Base64.getEncoder().encode(pattern.getBytes())); rule.setValue(encodedPattern); rules.add(rule); telemetry.setRules(rules); assertThrows(BadRequestException.class, () -> { underTest.validateAnonymizationRules(telemetry); }); }