Add Dockerfile and add app & tests for it

Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3.9-slim-bullseye
+
+SHELL ["/bin/bash", "-c"]
+WORKDIR /project
+
+ADD app /project/app
+COPY requirements.txt /project/
+
+RUN pip install --no-cache-dir -r /project/requirements.txt
+
+CMD ["faststream", "run", "--workers", "1", "app.application:app"]

app/application.py

@@ -0,0 +1,27 @@
+from pydantic import BaseModel, Field
+
+from faststream import FastStream, Logger
+from faststream.kafka import KafkaBroker
+
+
+class MultiplyMessage(BaseModel):
+    a: int = Field(..., examples=[2], description="Integer value")
+    b: int = Field(..., examples=[3], description="Integer value")
+
+
+class Results(BaseModel):
+    res: int = Field(..., examples=[6], description="Result of multiplication")
+
+
+broker = KafkaBroker("localhost:9092")
+app = FastStream(broker)
+
+
+@broker.subscriber("multiply")
+@broker.publisher("results")
+async def multiply_numbers(msg: MultiplyMessage, logger: Logger) -> Results:
+    logger.info(msg)
+
+    result = msg.a * msg.b
+    result_obj = Results(res=result)
+    return result_obj

pyproject.toml

@@ -0,0 +1,7 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "app"
+version = "0.0.1"

tests/test_application.py

@@ -0,0 +1,14 @@
+import pytest
+from faststream.kafka import TestKafkaBroker
+
+from app.application import MultiplyMessage, Results, broker, multiply_numbers
+
+
+@pytest.mark.asyncio
+async def test_multiply_numbers():
+    async with TestKafkaBroker(broker):
+        @broker.subscriber("results")
+        async def on_result(msg: Results):
+            assert msg.res == 6
+
+        await broker.publish(MultiplyMessage(a=2, b=3), "multiply")