refactor: replace --gateway flag with --asgi boolean flag (#383)

* refactor: replace --gateway flag with --asgi boolean flag

Simplify the CLI by replacing `--gateway asgi` with `--asgi`. The new flag is more
intuitive as WSGI remains the default and ASGI is opt-in. Also updates the environment
variable to FUNCTION_USE_ASGI for clarity.

* fix: update conformance tests to use --asgi flag

Author: taeold

.github/workflows/conformance-asgi.yml

@@ -52,39 +52,39 @@ jobs:
         functionType: 'http'
         useBuildpacks: false
         validateMapping: false
-        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_http --signature-type http --gateway asgi'"
+        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_http --signature-type http --asgi'"
 
     - name: Run CloudEvents conformance tests
       uses: GoogleCloudPlatform/functions-framework-conformance/action@72a4f36b10f1c6435ab1a86a9ea24bda464cc262 # v1.8.6
       with:
         functionType: 'cloudevent'
         useBuildpacks: false
         validateMapping: false
-        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_cloud_event --signature-type cloudevent --gateway asgi'"
+        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_cloud_event --signature-type cloudevent --asgi'"
 
     - name: Run HTTP conformance tests declarative
       uses: GoogleCloudPlatform/functions-framework-conformance/action@72a4f36b10f1c6435ab1a86a9ea24bda464cc262 # v1.8.6
       with:
         functionType: 'http'
         useBuildpacks: false
         validateMapping: false
-        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_http_declarative --gateway asgi'"
+        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_http_declarative --asgi'"
 
     - name: Run CloudEvents conformance tests declarative
       uses: GoogleCloudPlatform/functions-framework-conformance/action@72a4f36b10f1c6435ab1a86a9ea24bda464cc262 # v1.8.6
       with:
         functionType: 'cloudevent'
         useBuildpacks: false
         validateMapping: false
-        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_cloud_event_declarative --gateway asgi'"
+        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_cloud_event_declarative --asgi'"
 
     - name: Run HTTP concurrency tests declarative
       uses: GoogleCloudPlatform/functions-framework-conformance/action@72a4f36b10f1c6435ab1a86a9ea24bda464cc262 # v1.8.6
       with:
         functionType: 'http'
         useBuildpacks: false
         validateConcurrency: true
-        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_http_declarative_concurrent --gateway asgi'"
+        cmd: "'functions-framework --source tests/conformance/async_main.py --target write_http_declarative_concurrent --asgi'"
 
     # Note: Event (legacy) and Typed tests are not supported in ASGI mode
     # Note: validateMapping is set to false for CloudEvent tests because ASGI mode

src/functions_framework/_cli.py

@@ -33,14 +33,13 @@
 @click.option("--port", envvar="PORT", type=click.INT, default=8080)
 @click.option("--debug", envvar="DEBUG", is_flag=True)
 @click.option(
-    "--gateway",
-    envvar="FUNCTION_GATEWAY",
-    type=click.Choice(["wsgi", "asgi"]),
-    default="wsgi",
-    help="Server gateway interface type (wsgi for sync, asgi for async)",
+    "--asgi",
+    envvar="FUNCTION_USE_ASGI",
+    is_flag=True,
+    help="Use ASGI server for function execution",
 )
-def _cli(target, source, signature_type, host, port, debug, gateway):
-    if gateway == "asgi":  # pragma: no cover
+def _cli(target, source, signature_type, host, port, debug, asgi):
+    if asgi:  # pragma: no cover
         from functions_framework.aio import create_asgi_app
 
         app = create_asgi_app(target, source, signature_type)

tests/test_cli.py

@@ -119,7 +119,7 @@ def test_asgi_cli(monkeypatch):
     monkeypatch.setattr(functions_framework._cli, "create_server", create_server)
 
     runner = CliRunner()
-    result = runner.invoke(_cli, ["--target", "foo", "--gateway", "asgi"])
+    result = runner.invoke(_cli, ["--target", "foo", "--asgi"])
 
     assert result.exit_code == 0
     assert create_asgi_app.calls == [pretend.call("foo", None, "http")]