RedundantSetterCall
A field was set twice in the same chained expression.

Alternate names: ProtoRedundantSet

The problem

Proto and AutoValue builders provide a fluent interface for constructing instances. Unlike argument lists, however, they do not prevent the user from providing multiple values for the same field.

Setting the same field multiple times in the same chained expression is pointless (as the intermediate value will be overwritten), and can easily mask a bug, especially if the setter is called with different arguments.

return MyProto.newBuilder()
    .setFoo(copy.getFoo())
    .setFoo(copy.getBar())
    .build();

Suppression

Suppress false positives by adding the suppression annotation @SuppressWarnings("RedundantSetterCall") to the enclosing element.