Feature: get_program_price

src/aleph/sdk/client/abstract.py

@@ -7,6 +7,7 @@
 from typing import (
     Any,
     AsyncIterable,
+    Coroutine,
     Dict,
     Iterable,
     List,
@@ -40,7 +41,7 @@
 from aleph.sdk.utils import extended_json_encoder
 
 from ..query.filters import MessageFilter, PostFilter
-from ..query.responses import PostsResponse
+from ..query.responses import PostsResponse, PriceResponse
 from ..types import GenericMessage, StorageEnum
 from ..utils import Writable, compute_sha256
 
@@ -241,6 +242,18 @@ def watch_messages(
         """
         raise NotImplementedError("Did you mean to import `AlephHttpClient`?")
 
+    @abstractmethod
+    def get_program_price(
+        self,
+        item_hash: str,
+    ) -> Coroutine[Any, Any, PriceResponse]:
+        """
+        Get Program message Price
+
+        :param item_hash: item_hash of executable message
+        """
+        raise NotImplementedError("Did you mean to import `AlephHttpClient`?")
+
 
 class AuthenticatedAlephClient(AlephClient):
     account: Account

src/aleph/sdk/client/http.py

@@ -12,9 +12,14 @@
 from pydantic import ValidationError
 
 from ..conf import settings
-from ..exceptions import FileTooLarge, ForgottenMessageError, MessageNotFoundError
+from ..exceptions import (
+    FileTooLarge,
+    ForgottenMessageError,
+    InvalidHashError,
+    MessageNotFoundError,
+)
 from ..query.filters import MessageFilter, PostFilter
-from ..query.responses import MessagesResponse, Post, PostsResponse
+from ..query.responses import MessagesResponse, Post, PostsResponse, PriceResponse
 from ..types import GenericMessage
 from ..utils import (
     Writable,
@@ -392,3 +397,17 @@ async def watch_messages(
                         yield parse_message(data)
                 elif msg.type == aiohttp.WSMsgType.ERROR:
                     break
+
+    async def get_program_price(self, item_hash: str) -> PriceResponse:
+        async with self.http_session.get(f"/api/v0/price/{item_hash}") as resp:
+            try:
+                resp.raise_for_status()
+                response_json = await resp.json()
+                return PriceResponse(
+                    required_tokens=response_json["required_tokens"],
+                    payment_type=response_json["payment_type"],
+                )
+            except aiohttp.ClientResponseError as e:
+                if e.status == 400:
+                    raise InvalidHashError(f"Bad request or no such hash {item_hash}")
+                raise e

src/aleph/sdk/exceptions.py

@@ -78,3 +78,9 @@ def __init__(self, required_funds: float, available_funds: float):
         super().__init__(
             f"Insufficient funds: required {required_funds}, available {available_funds}"
         )
+
+
+class InvalidHashError(QueryError):
+    """The Hash is not valid"""
+
+    pass

src/aleph/sdk/query/responses.py

@@ -72,3 +72,10 @@ class MessagesResponse(PaginationResponse):
 
     messages: List[AlephMessage]
     pagination_item = "messages"
+
+
+class PriceResponse(BaseModel):
+    """Response from an aleph.im node API on the path /api/v0/price/{item_hash}"""
+
+    required_tokens: float
+    payment_type: str

tests/unit/conftest.py

@@ -8,6 +8,7 @@
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest as pytest
+from aiohttp import ClientResponseError
 from aleph_message.models import AggregateMessage, AlephMessage, PostMessage
 
 import aleph.sdk.chains.ethereum as ethereum
@@ -230,6 +231,10 @@ class CustomMockResponse(MockResponse):
         async def json(self):
             return resp
 
+        def raise_for_status(self):
+            if status >= 400:
+                raise ClientResponseError(None, None, status=status)
+
         @property
         def status(self):
             return status
@@ -259,6 +264,21 @@ def get(self, *_args, **_kwargs):
     return client
 
 
+def make_mock_get_session_400(
+    get_return_value: Union[Dict[str, Any], bytes]
+) -> AlephHttpClient:
+    class MockHttpSession(AsyncMock):
+        def get(self, *_args, **_kwargs):
+            return make_custom_mock_response(get_return_value, 400)
+
+    http_session = MockHttpSession()
+
+    client = AlephHttpClient(api_server="http://localhost")
+    client.http_session = http_session
+
+    return client
+
+
 @pytest.fixture
 def mock_session_with_rejected_message(
     ethereum_account, rejected_message

tests/unit/test_price.py

@@ -0,0 +1,33 @@
+import pytest
+
+from aleph.sdk.exceptions import InvalidHashError
+from aleph.sdk.query.responses import PriceResponse
+from tests.unit.conftest import make_mock_get_session, make_mock_get_session_400
+
+
+@pytest.mark.asyncio
+async def test_get_program_price_valid():
+    """
+    Test that the get_program_price method returns the correct PriceResponse
+    when given a valid item hash.
+    """
+    expected_response = {
+        "required_tokens": 3.0555555555555556e-06,
+        "payment_type": "superfluid",
+    }
+    mock_session = make_mock_get_session(expected_response)
+    async with mock_session:
+        response = await mock_session.get_program_price("cacacacacacaca")
+        assert response == PriceResponse(**expected_response)
+
+
+@pytest.mark.asyncio
+async def test_get_program_price_invalid():
+    """
+    Test that the get_program_price method raises an InvalidHashError
+    when given an invalid item hash.
+    """
+    mock_session = make_mock_get_session_400({"error": "Invalid hash"})
+    async with mock_session:
+        with pytest.raises(InvalidHashError):
+            await mock_session.get_program_price("invalid_item_hash")