See https://pants.readme.io/docs/target-api-concepts for more instructions.

register.py

from pants.build_graph.build_file_aliases import BuildFileAliases
from pants.build_graph.payload_field import PrimitiveField
from pants.build_graph.target import Target as TargetV1
from pants.engine.target import Target as TargetV2
from pants.engine.target import COMMON_TARGET_FIELDS, Dependencies, IntField, Sources

"""This sets up a new target called `elixir_tests`, with both a V1 definition and a V2 Target API definition.

In a BUILD file, this would look like:

elixir_tests(
  name="demo",
  sources=["test_demo.ex"],
  timeout=120,
)
"""

class ElixirTestTargetV1(TargetV1):
    default_sources_globs = ("test_*.ex",)

    @classmethod
    def alias(cls):
        return "elixir_tests"
 
    def __init__(self, sources=None, timeout=None, payload=None, **kwargs):
        if timeout < 0:
            raise ValueError(f"Invalid timeout field: {timeout}. Must be > 0.")
        payload = payload or Payload()
        payload.add_fields(
            {
                "sources": self.create_sources_field(
                    sources=sources, sources_rel_path=address.spec_path, key_arg="sources"
                ),
                "timeout": PrimitiveField(timeout),
            }
        )
        super().__init__(payload=payload, **kwargs)


class ElixirSources(Sources):
    default = ("test_*.ex",)

    
class ElixirTestTimeout(IntField):
    alias = "timeout"
 
        
class ElixirTestTargetV2(TargetV2):
    alias = "elixir_tests"
    core_fields = (*COMMON_TARGET_FIELDS, Dependencies, ElixirSources, ElixirTestTimeout)


def build_file_aliases():
    return BuildFileAliases(targets={ElixirTestTargetV1.alias(): ElixirTestTargetV1})


def target_types():
    return [ElixirTestTargetV2]