To update a Java Protobuf message in application code,
one calls toBuilder and mutates the builder,
and finally calls build().
Due to the wrapped nature of Gatling Expressions,
this can be quite clumsy to write.
One have to create a lambda and maybe use for-comprehensions
whenever an expression is required.
I asked myself if I could, but didn't stop to think if I should. So this two-file library was created to combine expressions with Java Protobuf messages.
This is not included in the Gatling-gRPC library to avoid confusion.
Assuming you're using
Gatling with Gradle,
add this line to the dependencies.
gatling 'com.github.phisgr:gatling-javapb:1.1.1'
Below is copied from
the unit tests.
For the .update extension method to work,
you need to import com.github.phisgr.gatling.javapb._.
val fooE: Expression[Foo] = Foo.getDefaultInstance
.update(_.addBarBuilder.setBaz)($("baz"))
.update[Bar](_.addBar)($("bar"))
.update(_.addAllBar)($("bars"))IntelliJ will insert a pair of brackets after the setter, delete them as we need the function reference.
In the demo project with Gradle, the Java generated code is used.
Unfortunately in the Java Protobuf classes, there is not a linkage of
a message type and its builder class.
Their relationship exists only in the return type
of the overridden toBuilder.
I managed to use macros to help the inference, and made an Intellij Scala Plugin Extension. There are not much documentation on the two, so I may have made some mistakes. Please let me know if you see how things can be improved.