Tests for the main class

LogMaskingConverterSpec.groovy

class LogMaskingConverterSpec extends Specification {
    
    @Shared
    LogMaskingConverter converter
    
    void setup() {
        converter = new LogMaskingConverter()
    }
    
    @Unroll
    void 'format() should mask sensitive data'() {
        setup:
            SimpleMessage message = new SimpleMessage(input)
            LogEvent logEvent = new Log4jLogEvent('LogMaskingConverterSpecLogger', new MarkerManager.Log4jMarker(LoggingMarkers.JSON.name), null, null, message, null)
            StringBuilder builder = new StringBuilder()
        
        when:
            converter.format(logEvent, builder)
        
        then:
            assert builder.toString() == expectedOutput
        
        where:
            input                                                          | expectedOutput
            '{"noMask": "foo"}'                                            | '{"noMask": "foo"}'
            '{"ssn": "1234567890", "id": "ABC-123", "private": "someKey"}' | '{"ssn": "****", "id": "ABC-123", "private": "****"}'
            'invalidJson'                                                  | 'invalidJson'
    }
}