test_functions_this.py

import pythonmonkey as pm
import subprocess
import weakref
import sys


def test_python_functions_self():
  def pyFunc(param):
    return param

  assert 1 == pyFunc(1)
  assert 2 == pm.eval("""(pyFunc) => {
    return pyFunc(2);
  }
  """)(pyFunc)
  assert 3 == pm.eval("""(pyFunc) => {
    let jsObj = {};
    jsObj.pyFunc = pyFunc;
    return pyFunc(3);
  }
  """)(pyFunc)


def test_python_methods_self():
  def pyFunc(self, param):
    return [self, param]

  class Class:
    pass
  Class.pyMethod = pyFunc

  pyObj = Class()
  result = pyObj.pyMethod(1)
  assert pyObj == result[0] and 1 == result[1]
  pyMethod = pyObj.pyMethod
  result = pyMethod(2)
  assert pyObj == result[0] and 2 == result[1]
  result = pm.eval("""(pyObj) => {
    return pyObj.pyMethod(3);
  }
  """)(pyObj)
  assert pyObj == result[0] and 3 == result[1]
  result = pm.eval("""(pyObj) => {
    let jsObj = {};
    jsObj.pyMethod = pyObj.pyMethod;
    return jsObj.pyMethod(4);
  }
  """)(pyObj)
  assert pyObj == result[0] and 4 == result[1]  # pyMethod is bound to pyObj, so `self` is not `jsObj`
  result = pm.eval("""(pyObj) => {
    let pyMethod = pyObj.pyMethod;
    return pyMethod(5);
  }
  """)(pyObj)
  assert pyObj == result[0] and 5 == result[1]  # pyMethod is bound to pyObj, so `self` is not `globalThis`


def test_javascript_functions_this():
  jsFunc = pm.eval("""
  (function(param) {
    return [this, param];
  })
  """)

  class Class:
    pass
  Class.jsFunc = jsFunc  # jsFunc is not bound to Class, so `this` will be `globalThis`, not the object

  pyObj = Class()
  jsObj = pm.eval("({})")
  jsObj.jsFunc = jsFunc
  globalThis = pm.eval("globalThis")
  result = jsFunc(1)
  assert globalThis == result[0] and 1 == result[1]
  result = pyObj.jsFunc(2)
  assert globalThis == result[0] and 2 == result[1]
  result = jsObj.jsFunc(3)
  assert jsObj == result[0] and 3 == result[1]
  result = pm.eval("""(jsFunc) => {
    return jsFunc(4);
  }
  """)(jsFunc)
  assert globalThis == result[0] and 4 == result[1]
  result = pm.eval("""(pyObj) => {
    return pyObj.jsFunc(5);
  }
  """)(pyObj)
  assert pyObj == result[0] and 5 == result[1]
  result = pm.eval("""(jsObj) => {
    return jsObj.jsFunc(6);
  }
  """)(jsObj)
  assert jsObj == result[0] and 6 == result[1]


def test_JSMethodProxy_this():
  jsFunc = pm.eval("""
  (function(param) {
    return [this, param];
  })
  """)

  class Class:
    pass

  pyObj = Class()
  pyObj.jsMethod = pm.JSMethodProxy(jsFunc, pyObj)  # jsMethod is bound to pyObj, so `this` will always be `pyObj`
  jsObj = pm.eval("({})")
  jsObj.jsMethod = pyObj.jsMethod
  globalThis = pm.eval("globalThis")
  result = pyObj.jsMethod(1)
  assert pyObj == result[0] and 1 == result[1]
  result = jsObj.jsMethod(2)
  assert pyObj == result[0] and 2 == result[1]
  result = pm.eval("""(pyObj) => {
    return pyObj.jsMethod(3);
  }
  """)(pyObj)
  assert pyObj == result[0] and 3 == result[1]
  result = pm.eval("""(jsObj) => {
    return jsObj.jsMethod(4);
  }
  """)(jsObj)
  assert pyObj == result[0] and 4 == result[1]

# require


def test_require_correct_this():
  subprocess.check_call('npm install crypto-js', shell=True)
  CryptoJS = pm.require('crypto-js')
  cipher = CryptoJS.SHA256("Hello, World!").toString()
  assert cipher == "dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f"
  subprocess.check_call('npm uninstall crypto-js', shell=True)


def test_require_correct_this_old_style_class():
  example = pm.eval("""
  () => {
    // old style class
    function Rectangle(w, h) {
      this.w = w;
      this.h = h;
    }

    Rectangle.prototype = {
      getThis: function () {
        return this;
      },
      getArea: function () {
        return this.w * this.h;
      },
    };

    // es5 class
    class Rectangle2 {
      constructor(w,h) {
        this.w = w;
        this.h = h;
      }

      getThis() {
        return this;
      }

      getArea() {
        return this.w * this.h;
      }
    }

    return { Rectangle: Rectangle, Rectangle2: Rectangle2};
  }
  """)()
  r = pm.new(example.Rectangle)(1, 2)

  assert r.getArea() == 2
  assert r.getThis() == r

  r2 = pm.new(example.Rectangle2)(1, 2)

  assert r2.getArea() == 2
  assert r2.getThis() == r2


def test_function_finalization():
  ref = []
  starting_ref_count = []

  def outerScope():
    def pyFunc():
      return 42

    ref.append(weakref.ref(pyFunc))
    starting_ref_count.append(sys.getrefcount(pyFunc))
    assert 42 == pm.eval("(func) => func()")(pyFunc)

    assert ref[0]() is pyFunc
    current_ref_count = sys.getrefcount(pyFunc)
    assert current_ref_count == starting_ref_count[0] + 1

  outerScope()
  pm.collect()  # this should collect the JS proxy to pyFunc, which should decref pyFunc
  # pyFunc should be collected by now
  assert ref[0]() is None