karatelabs/karate · warning

configure logging.mask: unknown key

Error message

configure logging.mask: unknown key '{}' (known: {})

What it means

LogMask.fromMap() validates the keys of the configure logging.mask map against KNOWN_KEYS. Unknown keys do not abort configuration — each is warned about with the full list of known keys, and valid options (replacement, headers, etc.) are still applied. It indicates a typo or stale option in the mask configuration.

Solutions

1. Compare your keys against the known list printed in the warning and fix the typo
2. Remove keys that no longer exist in your Karate version (check the LogMask javadoc/changelog)
3. Keep only supported keys (replacement, headers, ...) in the logging.mask map
4. Add a startup assertion in CI that parses warnings to catch misconfiguration early

Example fix

// before
karate.configure('logging.mask', { replacment: '***', headers: ['Authorization'] });
// after
karate.configure('logging.mask', { replacement: '***', headers: ['Authorization'] });

// JS: validate mask keys before configure
const known = ['replacement', 'headers'];
const mask = { replacement: '***', headers: ['Authorization'] };
for (const k of Object.keys(mask)) {
  if (!known.includes(k)) throw new Error('unknown logging.mask key: ' + k);
}
karate.configure('logging.mask', mask);

When it happens

Trigger: Calling configure logging.mask (e.g. in karate-config.js or a Feature Background) with a map containing a key not in LogMask.KNOWN_KEYS — typically a misspelled option or one removed/renamed in a newer Karate version.

Common situations: Typo like 'replacment' or 'header'; copying config from an older tutorial using a renamed key; IDE autocomplete lacking for the JS-side map literal.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• configure logging.mask: no usable rules — set at least one…
• configure logging.mask.patterns
• configure logging.mask.patterns
• configure ' ' is deprecated; use 'configure logging = }
• configure 'logging' expects a map, got

AI-assisted analysis of karatelabs/karate@a22eb90246 (2026-09-12). Data as JSON: /api/errors/43ca68fb86e28be3. Report an issue: GitHub.

Appendix: source

Thrown at karate-core/src/main/java/io/karatelabs/output/LogMask.java:87

                    List<String> jsonPaths,
                    List<PatternRule> patternRules,
                    String replacement,
                    JavaCallable enableForUri) {
        this.maskedHeadersLower = maskedHeadersLower;
        this.jsonPaths = jsonPaths;
        this.patternRules = patternRules;
        this.replacement = replacement;
        this.enableForUri = enableForUri;
    }

    @SuppressWarnings("unchecked")
    public static LogMask fromMap(Map<String, Object> map) {
        if (map == null || map.isEmpty()) {
            return null;
        }
        for (String key : map.keySet()) {
            if (!KNOWN_KEYS.contains(key)) {
                logger.warn("configure logging.mask: unknown key '{}' (known: {})", key, KNOWN_KEYS);
            }
        }
        String replacement = map.get("replacement") instanceof String s ? s : DEFAULT_REPLACEMENT;
        Set<String> headers = new LinkedHashSet<>();
        if (map.get("headers") instanceof List<?> list) {
            for (Object item : list) {
                if (item != null) {
                    headers.add(item.toString().toLowerCase());
                }
            }
        }
        List<String> jsonPaths = new ArrayList<>();
        if (map.get("jsonPaths") instanceof List<?> list) {
            for (Object item : list) {
                if (item != null) {
                    jsonPaths.add(item.toString());
                }
            }

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