feat: Enhance chat streaming and tool call processing (#498)

* feat: Enhance chat streaming and tool call processing

- Added support for MongoDB checkpointer in the chat streaming workflow.
- Introduced functions to process tool call chunks and sanitize arguments.
- Improved event message creation with additional metadata.
- Enhanced error handling for JSON serialization in event messages.
- Updated the frontend to convert escaped characters in tool call arguments.
- Refactored the workflow input preparation and initial message processing.
- Added new dependencies for MongoDB integration and tool argument sanitization.

* fix: Update MongoDB checkpointer configuration to use LANGGRAPH_CHECKPOINT_DB_URL

* feat: Add support for Postgres checkpointing and update README with database recommendations

* feat: Implement checkpoint saver functionality and update MongoDB connection handling

* refactor: Improve code formatting and readability in app.py and json_utils.py

* refactor: Clean up commented code and improve formatting in server.py

* refactor: Remove unused imports and improve code organization in app.py

* refactor: Improve code organization and remove unnecessary comments in app.py

* chore: use langgraph-checkpoint-postgres==2.0.21 to avoid the JSON convert issue in the latest version, implement chat stream persistant with Postgres

* feat: add MongoDB and PostgreSQL support for LangGraph checkpointing, enhance environment variable handling

* fix: update comments for clarity on Windows event loop policy

* chore: remove empty code changes in MongoDB and PostgreSQL checkpoint tests

* chore: clean up unused imports and code in checkpoint-related files

* chore: remove empty code changes in test_checkpoint.py

* chore: remove empty code changes in test_checkpoint.py

* chore: remove empty code changes in test_checkpoint.py

* test: update status code assertions in MCP endpoint tests to allow for 403 responses

* test: update MCP endpoint tests to assert specific status codes and enable MCP server configuration

* chore: remove unnecessary environment variables from unittest workflow

* fix: invert condition for MCP server configuration check to raise 403 when disabled

* chore: remove pymongo from test dependencies in uv.lock

* chore:  optimize the _get_agent_name method

* test: enhance ChatStreamManager tests for PostgreSQL and MongoDB initialization

* test: add persistence tests for ChatStreamManager with PostgreSQL and MongoDB

* test: add unit tests for ChatStreamManager initialization with PostgreSQL and MongoDB

* test: enhance persistence tests for ChatStreamManager with PostgreSQL and MongoDB to verify message aggregation

* test: add unit tests for ChatStreamManager with PostgreSQL and MongoDB

* test: add unit tests for ChatStreamManager initialization with PostgreSQL and MongoDB

* test: add unit tests for ChatStreamManager initialization with PostgreSQL and MongoDB

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

.github/workflows/unittest.yaml

@@ -12,6 +12,31 @@ permissions:
 jobs:
   test:
     runs-on: ubuntu-latest
+    services:
+      postgres:
+        image: postgres:15
+        env:
+          POSTGRES_DB: checkpointing_db
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+        ports: ["5432:5432"]
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+      mongodb:
+        image: mongo:6
+        env:
+          MONGO_INITDB_ROOT_USERNAME: admin
+          MONGO_INITDB_ROOT_PASSWORD: admin
+          MONGO_INITDB_DATABASE: checkpointing_db
+        ports: ["27017:27017"]
+        options: >-
+          --health-cmd "mongosh --eval 'db.runCommand(\"ping\").ok'"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 3
     steps:
     - uses: actions/checkout@v3