test(py): Add a dummy LSPS policy plugin, and an LSPS node fixture

We need something to test against, the dummy plugin just returns a
fixed result, so the `cln-lsps-servive` plugin has something to work
against.

Author: cdecker

libs/gl-testing/gltesting/__init__.py

@@ -1,5 +1,37 @@
+from pathlib import Path
 from .scheduler import Scheduler
 
+
+def get_plugins_dir():
+    """Get the path to the plugins directory.
+
+    This works both when running from source (where plugins is a sibling
+    of gltesting) and when installed via pip (where both gltesting and
+    plugins are installed into site-packages).
+
+    Returns:
+        Path: The absolute path to the plugins directory
+
+    Raises:
+        FileNotFoundError: If the plugins directory cannot be found
+    """
+    # Get the directory containing this __init__.py file (gltesting/)
+    package_dir = Path(__file__).parent
+
+    # Try to find plugins as a sibling directory
+    # This handles both source and installed cases since both directories
+    # are installed at the same level
+    plugins_dir = package_dir.parent / "plugins"
+
+    if plugins_dir.exists() and plugins_dir.is_dir():
+        return plugins_dir
+
+    raise FileNotFoundError(
+        f"Could not find plugins directory. Expected at: {plugins_dir}"
+    )
+
+
 __all__ = [
-    Scheduler
+    "Scheduler",
+    "get_plugins_dir",
 ]

libs/gl-testing/gltesting/fixtures.py

@@ -1,4 +1,5 @@
 # Pytest fixtures
+from rich.pretty import pprint
 import tempfile
 from .scheduler import Scheduler
 from gltesting.clients import Clients, Client
@@ -224,12 +225,38 @@ def grpc_web_proxy(scheduler, grpc_test_server):
 
 @pytest.fixture
 def node_grpc_web_proxy(scheduler):
-    """A grpc-web proxy that knows how to talk to nodes.
-    """
+    """A grpc-web proxy that knows how to talk to nodes."""
     p = GrpcWebProxy(scheduler=scheduler, grpc_port=0)
     p.handler_cls = NodeHandler
     p.start()
 
     yield p
 
     p.stop()
+
+
+@pytest.fixture
+def lsps_server(node_factory):
+    """Provision and start an LSPs server."""
+    from gltesting import get_plugins_dir
+
+    policy_plugin = get_plugins_dir() / "lsps2_policy.py"
+
+    lsp = node_factory.get_node(
+        options={
+            "experimental-lsps2-service": None,
+            "experimental-lsps2-promise-secret": "A" * 64,
+            "important-plugin": policy_plugin,
+            "disable-plugin": "cln-grpc",
+        }
+    )
+
+    # Most of the params below are ignored, this is just a smoke test either way
+    pprint(lsp.rpc.lsps2_policy_getpolicy())
+    pprint(
+        lsp.rpc.lsps2_policy_getchannelcapacity(
+            init_payment_size=10**6, scid="1x1x1", opening_fee_params=None
+        )
+    )
+
+    yield lsp

libs/gl-testing/plugins/lsps2_policy.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""A simple implementation of a LSPS2 compatible policy plugin. It is the job
+of this plugin to deliver a fee options menu to the LSPS2 service plugin.
+"""
+
+from pyln.client import Plugin
+from datetime import datetime, timedelta, timezone
+
+
+plugin = Plugin()
+
+
+@plugin.method("lsps2-policy-getpolicy")
+def lsps2_policy_getpolicy(request):
+    """Returns an opening fee menu for the LSPS2 plugin."""
+    now = datetime.now(timezone.utc)
+
+    # Is ISO 8601 format "YYYY-MM-DDThh:mm:ss.uuuZ"
+    valid_until = (now + timedelta(hours=1)).isoformat().replace("+00:00", "Z")
+
+    return {
+        "policy_opening_fee_params_menu": [
+            {
+                "min_fee_msat": "1000",
+                "proportional": 1000,
+                "valid_until": valid_until,
+                "min_lifetime": 2000,
+                "max_client_to_self_delay": 2016,
+                "min_payment_size_msat": "1000",
+                "max_payment_size_msat": "100000000",
+            },
+            {
+                "min_fee_msat": "1092000",
+                "proportional": 2400,
+                "valid_until": valid_until,
+                "min_lifetime": 1008,
+                "max_client_to_self_delay": 2016,
+                "min_payment_size_msat": "1000",
+                "max_payment_size_msat": "1000000",
+            },
+        ]
+    }
+
+
+@plugin.method("lsps2-policy-getchannelcapacity")
+def lsps2_policy_getchannelcapacity(request, init_payment_size, scid, opening_fee_params):
+    """Returns an opening fee menu for the LSPS2 plugin."""
+    return {"channel_capacity_msat": 100000000}
+
+
+plugin.run()

libs/gl-testing/pyproject.toml

@@ -37,4 +37,10 @@ build-backend = "hatchling.build"
 [tool.hatch.build]
 include = [
     "gltesting",
+    "plugins",
+]
+exclude = [
+    "**/.#*",
+    "**/*~",
+    "**/*.swp",
 ]