accessible/tests/browser/python_runner_wsh.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 """A pywebsocket3 handler which runs arbitrary Python code and returns the
   6 result.
   7 This is used to test OS specific accessibility APIs which can't be tested in JS.
   8 It is intended to be called from JS browser tests.
   9 """
  10
  11 import json
  12 import math
  13 import os
  14 import sys
  15 import traceback
  16
  17 from mod_pywebsocket import msgutil
  18
  19
  20 def web_socket_do_extra_handshake(request):
  21     pass
  22
  23
  24 def web_socket_transfer_data(request):
  25     def send(*args):
  26         """Send a response to the client as a JSON array."""
  27         msgutil.send_message(request, json.dumps(args))
  28
  29     cleanNamespace = {}
  30     testDir = None
  31     if sys.platform == "win32":
  32         testDir = "windows"
  33     elif sys.platform == "linux":
  34         testDir = "atk"
  35     if testDir:
  36         sys.path.append(
  37             os.path.join(
  38                 os.getcwd(), "browser", "accessible", "tests", "browser", testDir
  39             )
  40         )
  41         try:
  42             import a11y_setup
  43
  44             cleanNamespace = a11y_setup.__dict__
  45             setupExc = None
  46         except Exception:
  47             setupExc = traceback.format_exc()
  48         sys.path.pop()
  49
  50     def info(message):
  51         """Log an info message."""
  52         send("info", str(message))
  53
  54     cleanNamespace["info"] = info
  55     namespace = cleanNamespace.copy()
  56
  57     # Keep handling messages until the WebSocket is closed.
  58     while True:
  59         code = msgutil.receive_message(request)
  60         if not code:
  61             return
  62         if code == "__reset__":
  63             namespace = cleanNamespace.copy()
  64             send("return", None)
  65             continue
  66
  67         if setupExc:
  68             # a11y_setup failed. Report an exception immediately.
  69             send("exception", setupExc)
  70             continue
  71
  72         # Wrap the code in a function called run(). This allows the code to
  73         # return a result by simply using the return statement.
  74         if "\n" not in code and not code.lstrip().startswith("return "):
  75             # Single line without return. Assume this is an expression. We use
  76             # a lambda to return the result.
  77             code = f"run = lambda: {code}"
  78         else:
  79             lines = ["def run():"]
  80             # Indent each line inside the function.
  81             lines.extend(f"  {line}" for line in code.splitlines())
  82             code = "\n".join(lines)
  83         try:
  84             # Execute this Python code, which will define the run() function.
  85             exec(code, namespace)
  86             # Run the function we just defined.
  87             ret = namespace["run"]()
  88             if isinstance(ret, float) and math.isnan(ret):
  89                 # NaN can't be serialized by JSON.
  90                 ret = None
  91             send("return", ret)
  92         except Exception:
  93             send("exception", traceback.format_exc())