redacted-compiler-plugin

A multiplatform 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(SOURCE)
@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(SOURCE)
@Target(CLASS)
annotation class Redacted

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

SensitiveData(██)

Installation

Apply the gradle plugin.

plugins {
  id("dev.zacsweers.redacted") version <version>
}

And that's it! The default configuration will add the multiplatform -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!
  // Note that this must be in the format of a string where packages are delimited by '/' and
  // classes by '.', e.g. "kotlin/Map.Entry"
  redactedAnnotation = "dev/zacsweers/redacted/annotations/Redacted" // Default

  // Define a custom unredacted annotation.
  unredactedAnnotation = "dev/zacsweers/redacted/annotations/Unredacted" // 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
}

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

Supported platforms

The compiler plugin itself supports all multiplatform project types. The first-party annotations artifact is also multiplatform and supports all common JVM, JS, and native targets.

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.

Advanced Usage

In situations where it is desirable to redact everything and opt-out on certain properties, two options are provided:

Class redaction

For one-off classes that may contain a large number of fields that should be redacted, you can augment the @Redacted class behavior:

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

User(name=Bob, phoneNumber=██, ssn=██)

Supertype redaction

For situations where you need to enforce that an API only accepts redacted inputs, you can apply @Redacted to a parent interface.

@Redacted
interface RedactedObject

data class User(@Unredacted val name: String, val phoneNumber: String, val ssn: String) : RedactedObject

User(name=Bob, phoneNumber=██, ssn=██)

License

Copyright (C) 2018 Zac Sweers

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.