Listener errors in console: selenium.webdriver.chrome.webdriver.WebDriver is not JSON serializable

[alexandrul]

Using the Add Location Strategy keyword leads to multiple errors in both console and message logs.
Similar issue encountered in RIDE, which is using a similar TestRunnerAgent.py: https://github.com/robotframework/Selenium2Library/issues/542

Console errors:

[ ERROR ] Calling method 'start_keyword' of listener '...\TestRunnerAgent.py' failed: TypeError: <selenium.webdriver.chrome.webdriver.WebDriver (session="...")> is not JSON serializable
[ ERROR ] Calling method 'end_keyword' of listener '...\TestRunnerAgent.py' failed: TypeError: <selenium.webdriver.chrome.webdriver.WebDriver (session="...")> is not JSON serializable

Message log traceback:

20160818 14:40:06.115 : INFO : Traceback (most recent call last):
  File "...\TestRunnerAgent.py", line 441, in _send_socket
    self.streamhandler.dump(packet)
  File "...\TestRunnerAgent.py", line 671, in dump
    s = self._json_encoder(obj)
  File "...\Python27\lib\json\encoder.py", line 209, in encode
    chunks = list(chunks)
  File "...\Python27\lib\json\encoder.py", line 434, in _iterencode
    for chunk in _iterencode_dict(o, _current_indent_level):
  File "...\Python27\lib\json\encoder.py", line 408, in _iterencode_dict
    for chunk in chunks:
  File "...\Python27\lib\json\encoder.py", line 332, in _iterencode_list
    for chunk in chunks:
  File "...\Python27\lib\json\encoder.py", line 408, in _iterencode_dict
    for chunk in chunks:
  File "...\Python27\lib\json\encoder.py", line 332, in _iterencode_list
    for chunk in chunks:
  File "...\Python27\lib\json\encoder.py", line 442, in _iterencode
    o = _default(o)
  File "...\Python27\lib\json\encoder.py", line 184, in default
    raise TypeError(repr(o) + " is not JSON serializable")
TypeError: <selenium.webdriver.chrome.webdriver.WebDriver (session="605922e7d1ae544229972fdbcd5f74ac")> is not JSON serializable

[alexandrul]

Of course, monkey-patching can be used to avoid this, but the issue may occur in the future for other corner cases.

[adam-wypych]

Few questions about software version, which You are using :)

1. RED version?
2. Robot Framework?
3. Interpreter is python, jython or ironpython and in which version?
4. selenium library?

[alexandrul]

RED - Robot Editor version 0.6.5 0.6.5.201607071059
Eclipse Platform 4.6.0.I20160606-1100
robotframework 3.0.1.dev20151231
Python 2.7.12
selenium 2.53.6

[alexandrul]

However, the issue is in TestRunnerAgent.py, that's why I have skipped the environment details.

My workaround was to use http://stackoverflow.com/questions/18478287/making-object-json-serializable-with-regular-encoder to make selenium.webdriver.chrome.webdriver.WebDriver JSON serializable.

[adam-wypych]

We just think about modify a little bit attrs dictionary send to RED listener to send empty args list inside for start_keyword and end_keyword. As far as I've been tested it works with example provide by You.

The reason is that we do not depends on args when keyword is starting and correction is just one line attrs['args'] = [] before self._send_socket("start_keyword", name, attrs) and self._send_socket("end_keyword", name, attrs)

The correction will be available in new upcome release.

Information about listener API: http://robotframework.org/robotframework/latest/RobotFrameworkUserGuide.html#id760

[alexandrul]

Thank you for the pointers, it works just fine on my pc.

[adam-wypych]

Just for update, I checked it deeply and this issue is mainly connected to wrapping a call

BuiltIn().run_keyword(self, name, args*)

inside keyword call by user, where args contains complex object as one of parameter. I. e. I made library (KeywordLibrary.py) like this:

class User(object):
    def __init__(self, name, password):
        self.name = name
        self.password = password

kepler = User('A. Kepler', 'secret')

from robot.libraries.BuiltIn import BuiltIn

class KeywordLibrary:
    def keyword(self, name):
        pass

    def call_keyword(self):
        return BuiltIn().run_keyword("keyword", {"name": kepler})

the corresponding test case is very simple:

*** Settings ***
Library    KeywordLibrary.py

*** Test Cases ***
T1
    Call Keyword

The issue is also reproduce even Selenium is not used.

[kootstra]

I have encountered the same issue, and the suggested C:\Python27\lib\site-packages\robotide\contrib\testrunner\TestRunnerAgent.py alteration has the desired effect for RIDE, but sadly doesn't work with RED.

It seems to me that RED actually creates the TestRunnerAgent.py file from a different source as it refers to a temp file: C:\Users[user]\AppData\Local\Temp\RobotTempDir2655008392341869025\TestRunnerAgent.py. Does anyone know where to locate the original file?

When altering this temporary version, the errors do disappear, so when I have access to the original file it could be permanent. Otherwise after every RED application restart I have to do this again.

[alexandrul]

It is inside one of the jars (in my case it was in org.robotframework.ide.core-functions-0.0.1-SNAPSHOT.jar)

[kootstra]

Thanks. That should help. Will let you know tomorrow if that works for me.

[michalanglart]

@kootstra RED does not use the agent provided with RIDE. We provide our own version of it (modified version of what RIDE uses) which is located in the jar mentioned by @alexandrul. Upcoming RED release will of course provide the fix in agent code (we expect to release new version within 1-2 weeks).

[kootstra]

@michalanglart from the logs I already understood that the file is generated from one of the classes and does not use the one in Python directory.

After updating the TestRunnerAgent.py file in the org.robotframework.ide.core-functions-0.0.1-SNAPSHOT.jar class the errors dissapear. However, the debug functionality also no longer works. So, I guess that is one step forward, and two steps back.

[adam-wypych]

@kootstra Please download updated version, which will be included in new release: https://gist.githubusercontent.com/adam-wypych/4e23e33f051f7bd0713fcdbe8e17c733/raw/e7367b57254d94d22d01be46e72aad377b4c29b0/TestRunnerAgent.py .

[kootstra]

@adam-wypych Thanks. That indeed works. Looking forward to the new release.

[KrzysztofJozefowicz]

released in 0.7.0