Add support for async functions and async generators to `gr.ChatInter…

…face` (#5116)

* add support for async functions and iterators to ChatInterface

* fix api

* added support to examples

* add tests

* chat

* add changeset

* typing

* chat interface

* anyio

* anyio generator

---------

Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>

.changeset/moody-buttons-tell.md

@@ -0,0 +1,5 @@
+---
+"gradio": minor
+---
+
+feat:Add support for async functions and async generators to `gr.ChatInterface`

gradio/chat_interface.py

@@ -6,8 +6,9 @@
 from __future__ import annotations
 
 import inspect
-from typing import Callable, Generator
+from typing import AsyncGenerator, Callable
 
+import anyio
 from gradio_client import utils as client_utils
 from gradio_client.documentation import document, set_documentation_group
 
@@ -25,6 +26,7 @@
 from gradio.helpers import create_examples as Examples  # noqa: N812
 from gradio.layouts import Accordion, Column, Group, Row
 from gradio.themes import ThemeClass as Theme
+from gradio.utils import SyncToAsyncIterator, async_iteration
 
 set_documentation_group("chatinterface")
 
@@ -100,7 +102,12 @@ def __init__(
             theme=theme,
         )
         self.fn = fn
-        self.is_generator = inspect.isgeneratorfunction(self.fn)
+        self.is_async = inspect.iscoroutinefunction(
+            self.fn
+        ) or inspect.isasyncgenfunction(self.fn)
+        self.is_generator = inspect.isgeneratorfunction(
+            self.fn
+        ) or inspect.isasyncgenfunction(self.fn)
         self.examples = examples
         if self.space_id and cache_examples is None:
             self.cache_examples = True
@@ -397,67 +404,99 @@ def _display_input(
         history.append([message, None])
         return history, history
 
-    def _submit_fn(
+    async def _submit_fn(
         self,
         message: str,
         history_with_input: list[list[str | None]],
         *args,
-        **kwargs,
     ) -> tuple[list[list[str | None]], list[list[str | None]]]:
         history = history_with_input[:-1]
-        response = self.fn(message, history, *args, **kwargs)
+        if self.is_async:
+            response = await self.fn(message, history, *args)
+        else:
+            response = await anyio.to_thread.run_sync(
+                self.fn, message, history, *args, limiter=self.limiter
+            )
         history.append([message, response])
         return history, history
 
-    def _stream_fn(
+    async def _stream_fn(
         self,
         message: str,
         history_with_input: list[list[str | None]],
         *args,
-        **kwargs,
-    ) -> Generator[tuple[list[list[str | None]], list[list[str | None]]], None, None]:
+    ) -> AsyncGenerator:
         history = history_with_input[:-1]
-        generator = self.fn(message, history, *args, **kwargs)
+        if self.is_async:
+            generator = self.fn(message, history, *args)
+        else:
+            generator = await anyio.to_thread.run_sync(
+                self.fn, message, history, *args, limiter=self.limiter
+            )
+            generator = SyncToAsyncIterator(generator, self.limiter)
         try:
-            first_response = next(generator)
+            first_response = await async_iteration(generator)
             update = history + [[message, first_response]]
             yield update, update
         except StopIteration:
             update = history + [[message, None]]
             yield update, update
-        for response in generator:
+        async for response in generator:
             update = history + [[message, response]]
             yield update, update
 
-    def _api_submit_fn(
-        self, message: str, history: list[list[str | None]], *args, **kwargs
+    async def _api_submit_fn(
+        self, message: str, history: list[list[str | None]], *args
     ) -> tuple[str, list[list[str | None]]]:
-        response = self.fn(message, history)
+        if self.is_async:
+            response = await self.fn(message, history, *args)
+        else:
+            response = await anyio.to_thread.run_sync(
+                self.fn, message, history, *args, limiter=self.limiter
+            )
         history.append([message, response])
         return response, history
 
-    def _api_stream_fn(
-        self, message: str, history: list[list[str | None]], *args, **kwargs
-    ) -> Generator[tuple[str | None, list[list[str | None]]], None, None]:
-        generator = self.fn(message, history, *args, **kwargs)
+    async def _api_stream_fn(
+        self, message: str, history: list[list[str | None]], *args
+    ) -> AsyncGenerator:
+        if self.is_async:
+            generator = self.fn(message, history, *args)
+        else:
+            generator = await anyio.to_thread.run_sync(
+                self.fn, message, history, *args, limiter=self.limiter
+            )
+            generator = SyncToAsyncIterator(generator, self.limiter)
         try:
-            first_response = next(generator)
+            first_response = await async_iteration(generator)
             yield first_response, history + [[message, first_response]]
         except StopIteration:
             yield None, history + [[message, None]]
-        for response in generator:
+        async for response in generator:
             yield response, history + [[message, response]]
 
-    def _examples_fn(self, message: str, *args, **kwargs) -> list[list[str | None]]:
-        return [[message, self.fn(message, [], *args, **kwargs)]]
+    async def _examples_fn(self, message: str, *args) -> list[list[str | None]]:
+        if self.is_async:
+            response = await self.fn(message, [], *args)
+        else:
+            response = await anyio.to_thread.run_sync(
+                self.fn, message, [], *args, limiter=self.limiter
+            )
+        return [[message, response]]
 
-    def _examples_stream_fn(
+    async def _examples_stream_fn(
         self,
         message: str,
         *args,
-        **kwargs,
-    ) -> Generator[list[list[str | None]], None, None]:
-        for response in self.fn(message, [], *args, **kwargs):
+    ) -> AsyncGenerator:
+        if self.is_async:
+            generator = self.fn(message, [], *args)
+        else:
+            generator = await anyio.to_thread.run_sync(
+                self.fn, message, [], *args, limiter=self.limiter
+            )
+            generator = SyncToAsyncIterator(generator, self.limiter)
+        async for response in generator:
             yield [[message, response]]
 
     def _delete_prev_fn(

scripts/format_backend.sh

@@ -5,5 +5,6 @@ cd "$(dirname ${0})/.."
 echo "Formatting the backend... Our style follows the Black code style."
 ruff --fix gradio test
 black gradio test
+bash scripts/type_check_backend.sh
 
 bash client/python/scripts/format.sh  # Call the client library's formatting script

test/test_chat_interface.py

@@ -15,11 +15,20 @@ def double(message, history):
     return message + " " + message
 
 
+async def async_greet(message, history):
+    return "hi, " + message
+
+
 def stream(message, history):
     for i in range(len(message)):
         yield message[: i + 1]
 
 
+async def async_stream(message, history):
+    for i in range(len(message)):
+        yield message[: i + 1]
+
+
 def count(message, history):
     return str(len(history))
 
@@ -68,7 +77,8 @@ def test_events_attached(self):
             )
 
     @pytest.mark.asyncio
-    async def test_example_caching(self):
+    async def test_example_caching(self, monkeypatch):
+        monkeypatch.setattr(helpers, "CACHED_FOLDER", tempfile.mkdtemp())
         chatbot = gr.ChatInterface(
             double, examples=["hello", "hi"], cache_examples=True
         )
@@ -77,6 +87,17 @@ async def test_example_caching(self):
         assert prediction_hello[0][0] == ["hello", "hello hello"]
         assert prediction_hi[0][0] == ["hi", "hi hi"]
 
+    @pytest.mark.asyncio
+    async def test_example_caching_async(self, monkeypatch):
+        monkeypatch.setattr(helpers, "CACHED_FOLDER", tempfile.mkdtemp())
+        chatbot = gr.ChatInterface(
+            async_greet, examples=["abubakar", "tom"], cache_examples=True
+        )
+        prediction_hello = await chatbot.examples_handler.load_from_cache(0)
+        prediction_hi = await chatbot.examples_handler.load_from_cache(1)
+        assert prediction_hello[0][0] == ["abubakar", "hi, abubakar"]
+        assert prediction_hi[0][0] == ["tom", "hi, tom"]
+
     @pytest.mark.asyncio
     async def test_example_caching_with_streaming(self, monkeypatch):
         monkeypatch.setattr(helpers, "CACHED_FOLDER", tempfile.mkdtemp())
@@ -88,6 +109,17 @@ async def test_example_caching_with_streaming(self, monkeypatch):
         assert prediction_hello[0][0] == ["hello", "hello"]
         assert prediction_hi[0][0] == ["hi", "hi"]
 
+    @pytest.mark.asyncio
+    async def test_example_caching_with_streaming_async(self, monkeypatch):
+        monkeypatch.setattr(helpers, "CACHED_FOLDER", tempfile.mkdtemp())
+        chatbot = gr.ChatInterface(
+            async_stream, examples=["hello", "hi"], cache_examples=True
+        )
+        prediction_hello = await chatbot.examples_handler.load_from_cache(0)
+        prediction_hi = await chatbot.examples_handler.load_from_cache(1)
+        assert prediction_hello[0][0] == ["hello", "hello"]
+        assert prediction_hi[0][0] == ["hi", "hi"]
+
     @pytest.mark.asyncio
     async def test_example_caching_with_additional_inputs(self, monkeypatch):
         monkeypatch.setattr(helpers, "CACHED_FOLDER", tempfile.mkdtemp())
@@ -138,12 +170,25 @@ def test_streaming_api(self, connect):
             wait([job])
             assert job.outputs() == ["h", "he", "hel", "hell", "hello"]
 
+    def test_streaming_api_async(self, connect):
+        chatbot = gr.ChatInterface(async_stream).queue()
+        with connect(chatbot) as client:
+            job = client.submit("hello")
+            wait([job])
+            assert job.outputs() == ["h", "he", "hel", "hell", "hello"]
+
     def test_non_streaming_api(self, connect):
         chatbot = gr.ChatInterface(double)
         with connect(chatbot) as client:
             result = client.predict("hello")
             assert result == "hello hello"
 
+    def test_non_streaming_api_async(self, connect):
+        chatbot = gr.ChatInterface(async_greet)
+        with connect(chatbot) as client:
+            result = client.predict("gradio")
+            assert result == "hi, gradio"
+
     def test_streaming_api_with_additional_inputs(self, connect):
         chatbot = gr.ChatInterface(
             echo_system_prompt_plus_message,