https://afanasev.net/categories/data-class/Recent content in Data-Class on afanasev.netHugoen-USTue, 13 Aug 2019 15:00:00 +0700https://afanasev.net/kotlin/data-class/2019/08/13/kotlin-data-class-tostirng-hide.htmlTue, 13 Aug 2019 15:00:00 +0700https://afanasev.net/kotlin/data-class/2019/08/13/kotlin-data-class-tostirng-hide.html<p><em>This post describes how to remove class properties from the <code>toString()</code> method manually if you prefer not to use the <a href="https://afanasev.net/kotlin-library/2019/08/13/sekret.html">Sekret</a> compiler plugin.</em></p> <hr> <p>Kotlin&rsquo;s data class <code>toString</code> is generated automatically to include every property defined in the primary constructor. This is convenient for debugging but problematic when some of those properties contain sensitive data — passwords, tokens, PII — that must not appear in logs, crash reports, or analytics pipelines.</p> <p>There is no built-in Kotlin mechanism to exclude a specific field from the generated <code>toString</code> while keeping it in <code>equals</code>, <code>hashCode</code>, and <code>copy</code>. The language does not (yet) offer an annotation equivalent to <code>@Transient</code> for serialization. The approaches below represent the practical trade-offs available in pure Kotlin, each with distinct implications for class semantics, mutability, and maintainability.</p>