Embedding ChakraCore into Python apps.

main.py

# -*- coding: utf-8 -*-
# Hello World!
# see: https://github.com/Microsoft/ChakraCore/wiki/Embedding-ChakraCore
from ctypes import *

cc = cdll.LoadLibrary('ChakraCore')

# typedef void (CALLBACK *JsBackgroundWorkItemCallback)(_In_opt_ void *callbackState);
JsBackgroundWorkItemCallback = CFUNCTYPE(None, c_void_p)

# typedef bool (CALLBACK *JsThreadServiceCallback)(_In_ JsBackgroundWorkItemCallback callback, _In_opt_ void *callbackState);
JsThreadServiceCallback = CFUNCTYPE(c_bool, JsBackgroundWorkItemCallback, c_void_p)


# typedef void *JsRuntimeHandle;
JsRuntimeHandle = POINTER(c_uint)

# typedef void *JsRef;
JsRef = POINTER(c_uint)

# typedef JsRef JsContextRef;
JsContextRef = POINTER(c_uint)

# typedef JsRef JsValueRef;
JsValueRef = POINTER(c_uint)


# typedef DWORD_PTR JsSourceContext;
JsSourceContext = c_int64

###
### JSRT Const References
###
JS_INVALID_REFERENCE = JsRef()
JS_INVALID_RUNTIME_HANDLE = JsRuntimeHandle()
JS_SOURCE_CONTEXT_NONE = JsSourceContext(-1)


###
### JSRT Enum References
## enum JsErrorCode
JsErrorCode = c_uint32
JsNoError = 0
...


## enum JsRuntimeAttributes
JsRuntimeAttributes = c_uint32
JsRuntimeAttributeNone = JsRuntimeAttributes(0x00000000)
JsRuntimeAttributeDisableBackgroundWork = JsRuntimeAttributes(0x00000001)
JsRuntimeAttributeAllowScriptInterrupt = JsRuntimeAttributes(0x00000002)
JsRuntimeAttributeEnableIdleProcessing = JsRuntimeAttributes(0x00000004)
JsRuntimeAttributeDisableNativeCodeGeneration = JsRuntimeAttributes(0x00000008)
JsRuntimeAttributeDisableEval = JsRuntimeAttributes(0x00000010)
JsRuntimeAttributeEnableExperimentalFeatures = JsRuntimeAttributes(0x00000020)
JsRuntimeAttributeDispatchSetExceptionsToDebugger = JsRuntimeAttributes(0x00000040)
JsRuntimeAttributeDisableFatalOnOOM = JsRuntimeAttributes(0x00000080)



###
### JSRT API References
###

"""
STDAPI_(JsErrorCode)
    JsCreateRuntime(
    _In_ JsRuntimeAttributes attributes,
    _In_opt_ JsThreadServiceCallback threadService,
    _Out_ JsRuntimeHandle *runtime);
"""
JsCreateRuntime = cc.JsCreateRuntime
JsCreateRuntime.argtypes = [JsRuntimeAttributes, JsThreadServiceCallback, POINTER(JsRuntimeHandle)]
JsCreateRuntime.restype = JsErrorCode

"""
STDAPI_(JsErrorCode)
    JsCreateContext(
    _In_ JsRuntimeHandle runtime,
    _Out_ JsContextRef *newContext);
"""
JsCreateContext = cc.JsCreateContext
JsCreateContext.argtypes = [JsRuntimeHandle, POINTER(JsContextRef)]
JsCreateContext.restype = JsErrorCode

"""
STDAPI_(JsErrorCode)
    JsSetCurrentContext(
    _In_ JsContextRef context);
"""
JsSetCurrentContext = cc.JsSetCurrentContext
JsSetCurrentContext.argtypes = [JsContextRef]
JsSetCurrentContext.restype = JsErrorCode


"""
STDAPI_(JsErrorCode)
    JsRunScript(
    _In_z_ const wchar_t *script,
    _In_ JsSourceContext sourceContext,
    _In_z_ const wchar_t *sourceUrl,
    _Out_ JsValueRef *result);
"""
JsRunScript = cc.JsRunScript
JsRunScript.argtypes = [c_wchar_p, JsSourceContext, c_wchar_p, POINTER(JsValueRef)]
JsRunScript.restype = JsErrorCode

"""
STDAPI_(JsErrorCode)
    JsConvertValueToString(
    _In_ JsValueRef value,
    _Out_ JsValueRef *stringValue);
"""
JsConvertValueToString = cc.JsConvertValueToString
JsConvertValueToString.argtypes = [JsValueRef, POINTER(JsValueRef)]
JsConvertValueToString.restype = JsErrorCode

"""
STDAPI_(JsErrorCode)
    JsStringToPointer(
    _In_ JsValueRef value,
    _Outptr_result_buffer_(*stringLength) const wchar_t **stringValue,
    _Out_ size_t *stringLength);
"""
JsStringToPointer = cc.JsStringToPointer
JsStringToPointer.argtypes = [JsValueRef, POINTER(c_wchar_p), POINTER(c_size_t)]
JsStringToPointer.restype = JsErrorCode


"""
STDAPI_(JsErrorCode)
    JsDisposeRuntime(
    _In_ JsRuntimeHandle runtime);
"""
JsDisposeRuntime = cc.JsDisposeRuntime
JsDisposeRuntime.argtypes = [JsRuntimeHandle]
JsDisposeRuntime.restype = JsErrorCode



def main():
  runtime = JsRuntimeHandle()
  context = JsContextRef()
  result = JsValueRef()
  currentSourceContext = 0
  empty_str = create_unicode_buffer('')

  #  Your script; try replace hello-world with something else
  script = create_unicode_buffer("(()=>{return \'Hello world!\';})()")
  
  # create a runtime
  JsCreateRuntime(JsRuntimeAttributeNone, JsThreadServiceCallback(), byref(runtime))
  # create an execution context
  JsCreateContext(runtime, byref(context))
  # Now set the current execution context.
  JsSetCurrentContext(context)
  # Run the script.
  JsRunScript(script, currentSourceContext, empty_str, byref(result))
  currentSourceContext += 1
  # Convert your script result to String in JavaScript; redundant if your script returns a String
  resultJSString = JsValueRef()
  JsConvertValueToString(result, byref(resultJSString))
  # Project script result back to Python.
  resultWC = c_wchar_p()
  stringLength = c_size_t()
  JsStringToPointer(resultJSString, byref(resultWC), byref(stringLength))
  print(wstring_at(resultWC))
  
  # Dispose runtime
  JsSetCurrentContext(JS_INVALID_REFERENCE);
  JsDisposeRuntime(runtime);
  return 0



if __name__=='__main__':
  main()