refactor(api): move signal receiver out from init_app

This ensures that we can write unit tests for them.

api/extensions/ext_request_logging.py

@@ -2,60 +2,71 @@ import json
 import logging
 
 import flask
+import werkzeug.http
 from flask import Flask
 from flask.signals import request_finished, request_started
 
 from configs import dify_config
 
-logger = logging.getLogger(__name__)
+_logger = logging.getLogger(__name__)
+
+
+def _is_content_type_json(content_type: str) -> bool:
+    if not content_type:
+        return False
+    content_type_no_option, _ = werkzeug.http.parse_options_header(content_type)
+    return content_type_no_option.lower() == "application/json"
+
+
+def _log_request_started(_sender, **_extra):
+    """Log the start of a request."""
+    if not _logger.isEnabledFor(logging.DEBUG):
+        return
+
+    request = flask.request
+    if not (_is_content_type_json(request.content_type) and request.data):
+        _logger.debug("Received Request %s -> %s", request.method, request.path)
+        return
+    try:
+        json_data = json.loads(request.data)
+    except (TypeError, ValueError):
+        _logger.exception("Failed to parse JSON request")
+    formatted_json = json.dumps(json_data, ensure_ascii=False, indent=2)
+    _logger.debug(
+        "Received Request %s -> %s, Request Body:\n%s",
+        request.method,
+        request.path,
+        formatted_json,
+    )
+
+
+def _log_request_finished(_sender, response, **_extra):
+    """Log the end of a request."""
+    if not _logger.isEnabledFor(logging.DEBUG) or response is None:
+        return
+
+    if not _is_content_type_json(response.content_type):
+        _logger.debug("Response %s %s", response.status, response.content_type)
+        return
+
+    response_data = response.get_data(as_text=True)
+    try:
+        json_data = json.loads(response_data)
+    except (TypeError, ValueError):
+        _logger.exception("Failed to parse JSON response")
+
+    formatted_json = json.dumps(json_data, ensure_ascii=False, indent=2)
+    _logger.debug(
+        "Response %s %s, Response Body:\n%s",
+        response.status,
+        response.content_type,
+        formatted_json,
+    )
 
 
 def init_app(app: Flask):
     """Initialize the request logging extension."""
     if not dify_config.ENABLE_REQUEST_LOGGING:
         return
-
-    @request_started.connect_via(app)
-    def log_request_started(sender, **extra):
-        """Log the start of a request."""
-        if not logger.isEnabledFor(logging.DEBUG):
-            return
-
-        request = flask.request
-        content_type = request.content_type
-        if request.data and "application/json" in content_type.lower():
-            try:
-                json_data = json.loads(request.data)
-                formatted_json = json.dumps(json_data, ensure_ascii=False, indent=2)
-                logger.debug(
-                    "Received Request %s -> %s, Request Body:\n%s",
-                    request.method,
-                    request.path,
-                    formatted_json,
-                )
-            except Exception:
-                logger.exception("Failed to parse JSON request")
-        else:
-            logger.debug("Received Request %s -> %s", request.method, request.path)
-
-    @request_finished.connect_via(app)
-    def log_request_finished(sender, response, **extra):
-        """Log the end of a request."""
-        if not logger.isEnabledFor(logging.DEBUG) or response is None:
-            return
-
-        if response.content_type and "application/json" in response.content_type.lower():
-            try:
-                response_data = response.get_data(as_text=True)
-                json_data = json.loads(response_data)
-                formatted_json = json.dumps(json_data, ensure_ascii=False, indent=2)
-                logger.debug(
-                    "Response %s %s, Response Body:\n%s",
-                    response.status,
-                    response.content_type,
-                    formatted_json,
-                )
-            except Exception:
-                logger.exception("Failed to parse JSON response")
-        else:
-            logger.debug("Response %s %s", response.status, response.content_type)
+    request_started.connect(_log_request_started, app)
+    request_finished.connect(_log_request_finished, app)