redacted-compiler-plugin

A Kotlin compiler plugin that generates redacted toString() implementations.

Inspired by the auto-value-redacted extension for AutoValue.

Usage

Include the gradle plugin in your project, define a @Redacted annotation, and apply it to any properties that you wish to redact.

@Retention(BINARY)
@Target(PROPERTY)
annotation class Redacted

data class User(val name: String, @Redacted val phoneNumber: String)

When you call toString() any @Redacted properties are hidden:

User(name=Bob, phoneNumber=██)

If your annotation is applied to the class, then toString() will emit a single replacement string:

@Retention(BINARY)
@Target(CLASS)
annotation class Redacted

@Redacted
data class SensitiveData(val ssn: String, val birthday: String)

SensitiveData(██)

Installation

Apply the gradle plugin.

buildscript {
  dependencies {
    classpath "dev.zacsweers.redacted:redacted-compiler-plugin-gradle:x.y.z"
  }  
}

apply plugin: 'dev.zacsweers.redacted.redacted-gradle-plugin'

And that's it! The default configuration will add the -annotations artifact (which has a @Redacted annotation you can use) and wire it all automatically. Just annotate what you want to redact.

You can configure custom behavior with properties on the redacted extension.

redacted {
  // Define a custom annotation. The -annotations artifact won't be automatically added to
  // dependencies if you define your own!
  redactedAnnotation = "dev.zacsweers.redacted.annotations.Redacted" // Default

  // Define whether or not this is enabled. Useful if you want to gate this behind a dynamic
  // build configuration.
  enabled = true // Default

  // Define a custom replacement string for redactions.
  replacementString = "██" // Default
}

Android Per-Variant Configuration

If using Android, you can optionally configure the plugin to be applied on a per-variant basis via androidVariantFilter. This is similar to the Android Gradle Plugin's native variantFilter API, except with an overrideEnabled function to override the enabled status and there is no defaultConfig property. If not overridden, the default is to match the redacted extension's value. Other VariantFilter APIs should behave as expected (buildType, flavors, name, etc).

Note: Variants with different enabled values will have to be compiled separately. This is common in most multi-variant projects anyway, but something to be aware of.

redacted {
  enabled = true // Default
  androidVariantFilter {
    // Don't enable on debug
    if (buildType.name == "debug") {
      overrideEnabled(false)
    }
  }
}

Snapshots of the development version are available in Sonatype's snapshots repository.

Caveats

Kotlin compiler plugins are not a stable API! Compiled outputs from this plugin should be stable, but usage in newer versions of kotlinc are not guaranteed to be stable.
IDE support is not currently possible. See #8.

License