isabella232 / api-plumber-doclet

I'm in your API, checking for leaks

API Plumber doclet

A custom doclet to check that an API doesn't leak a set of "forbidden" packages.

Why

• coding conventions: Java's visibility system lacks flexibility. One workaround is to use a naming convention with api / internal root packages. The public API should not leak any internal types.
• shaded libraries: the API should not leak any shaded types.

Usage

Command line

javadoc -preventleak com.package1 [-preventleak com.package2] \
        -doclet com.datastax.oss.doclet.ApiPlumber ...

Maven

<plugin>
  <artifactId>maven-javadoc-plugin</artifactId>
  <executions>
    <execution>
      <id>check-api-leaks</id>
      <goals><goal>javadoc</goal></goals>
      <phase>process-classes</phase>
      <configuration>
        <doclet>com.datastax.oss.doclet.ApiPlumber</doclet>
        <docletArtifact>
          <groupId>com.datastax.oss</groupId>
          <artifactId>api-plumber-doclet</artifactId>
          <version>...</version>
        </docletArtifact>
        <additionalJOptions>
          <additionalparam>-preventleak</additionalparam>
          <additionalparam>com.package1</additionalparam>
          <additionalparam>-preventleak</additionalparam>
          <additionalparam>com.package2</additionalparam>
        </additionalJOptions>
        <useStandardDocletOptions>false</useStandardDocletOptions>
      </configuration>
    </execution>
  </executions>
</plugin>

Violations are printed on the standard error, and cause the command to return with a non-zero exit value.

You can ignore elements with a javadoc tag:

/** @leaks-private-api */
public com.example.internal.InternalType myField;