Cucumber JVM JSON and HTML formatters emit step arguments without built-in secret redaction

Short answer

No. Cucumber JVM does not provide a supported, version-stable extension point for post-processing built-in JSON or HTML formatter output before it is written to disk. A custom formatter can write its own files, but it cannot reliably suppress or alter the argument serialization performed by the built-in JSON or HTML plugins, and attempting this across major releases risks diverging from the official report schema.

Confirmed facts and likely explanation

Confirmed facts

• The built-in JSON and HTML formatters serialize scenario names, step arguments, and table cells directly into report files with no built-in masking or redaction.
• The core distribution has no formatter property, annotation, or plugin option that filters or transforms argument text before serialization.
• Tag expressions select which scenarios run, but they do not prevent hooks or step definitions from reading scenario data, so they are not a permission boundary for report content.
• Formatter plugin classes, event packages, and output structure differ between Cucumber JVM major versions.

Likely explanation

The formatter API is designed for report emission, not for intercepting or mutating another formatter's output. Events are not intended to be altered for downstream listeners, so there is no stable hook to scrub values between formatting and disk write.

Recommended configuration

1. Replace real credentials in Gherkin with placeholders such as <api-key> or <password>.
2. Resolve sensitive values at runtime inside step definitions from environment variables or a secret store, never from feature files.
3. Keep secrets out of scenario names, step arguments, and table cells.
4. Treat generated JSON and HTML as untrusted artifacts. Add a CI step that parses generated reports and scrubs sentinel values before archiving.
5. After scrubbing, re-grep archived reports for the sentinel and common secret patterns.

Verification

1. Run a scenario containing a unique sentinel secret in a step argument with --plugin json:target/cucumber.json and --plugin html:target/cucumber.html.
2. grep the generated files for the sentinel to confirm unredacted emission.
3. Inspect the installed Cucumber JVM JAR for the Formatter and EventListener contracts and check release notes for formatter API stability.
4. Register a custom formatter through --plugin and verify that it cannot suppress or alter output from the built-in JSON or HTML formatters.

Missing diagnostic detail: which Cucumber JVM major version are you using? Formatter APIs break between major releases, so this determines whether any custom formatter work is worth attempting.

This is a conservative draft for human review. Verify formatter behavior against your exact Cucumber JVM release before adopting a custom plugin or CI scrub step.