User script exception handler[squash]

fixing 2837, added test
unified-function
deleting the wrong commit

mitmproxy/addons/script.py

@@ -5,6 +5,7 @@ import time
 import sys
 import types
 import typing
+import traceback
 
 from mitmproxy import addonmanager
 from mitmproxy import exceptions
@@ -36,6 +37,25 @@ def load_script(path: str) -> types.ModuleType:
         sys.path[:] = oldpath
 
 
+def script_error_handler(path, exc, msg="", tb=False):
+    """
+        Handles all the user's script errors with
+        an optional traceback
+    """
+    exception = type(exc).__name__
+    if msg:
+        exception = msg
+    lineno = ""
+    if hasattr(exc, "lineno"):
+        lineno = str(exc.lineno)
+    log_msg = "Error in Script {}:{} {}".format(path, lineno, exception)
+    if tb:
+        etype, value, tback = sys.exc_info()
+        tback = addonmanager.cut_traceback(tback, "invoke_addon")
+        log_msg = log_msg.join(["\n"] + traceback.format_exception(etype, value, tback))
+    ctx.log.error(log_msg)
+
+
 class Script:
     """
         An addon that manages a single script.

test/mitmproxy/addons/test_script.py

@@ -243,6 +243,18 @@ class TestScriptLoader:
             tctx.invoke(sc, "tick")
             assert len(tctx.master.addons) == 1
 
+    def test_script_error_handler(self):
+        path = "/sample/path/example.py"
+        exc = SyntaxError
+        msg = "Error raised"
+        tb = True
+        with taddons.context() as tctx:
+            script.script_error_handler(path, exc, msg, tb)
+            assert tctx.master.has_log("/sample/path/example.py")
+            assert tctx.master.has_log("Error raised")
+            assert tctx.master.has_log("lineno")
+            assert tctx.master.has_log("NoneType")
+
     def test_order(self):
         rec = tutils.test_data.path("mitmproxy/data/addonscripts/recorder")
         sc = script.ScriptLoader()