README

code/tests/functional/tests/functions/README.md

@@ -1 +1,33 @@
-wip
+# Azure Functions Tests
+
+The functional tests for Azure Functions do not run the Azure functions locally, but instead invoke the entrypoints of the Python functions directly within each test.
+
+For example, consider the following:
+
+```py
+import azure.functions as func
+
+app = func.FunctionApp()
+
+@app.function_name(name="HttpTrigger1")
+@app.route(route="req")
+def main(req):
+    user = req.params.get("user")
+    return f"Hello, {user}!"
+```
+
+Instead of making an HTTP request to `/api/req` from within a test, import the function directly and call the function with a payload similar to what would be
+expected when running in Azure.
+
+
+```py
+req = func.HttpRequest(
+    method="GET",
+    url="http://localhost:7071/api/req",
+    body=b"",
+)
+
+main.build().get_user_function()(req)
+```
+
+Downstream dependcies are mocked using [pytest-httpserver](https://pytest-httpserver.readthedocs.io/).