Add RequirableContext, to allow Python/JS requires

dukpy/__init__.py

@@ -1,5 +1,5 @@
-from .evaljs import evaljs, Context
+from .evaljs import evaljs, Context, RequirableContext
 from ._dukpy import JSRuntimeError
 from .coffee import coffee_compile
 from .babel import babel_compile
-from .tsc import typescript_compile
+from .tsc import typescript_compile

dukpy/evaljs.py

@@ -1,5 +1,8 @@
 from . import _dukpy
 
+import os.path
+import importlib
+
 try:  # pragma: no cover
     unicode
     string_types = (str, unicode)
@@ -29,6 +32,60 @@ def evaljs(self, code, **kwargs):
         return _dukpy.ctx_eval_string(self._ctx, jscode, kwargs)
 
 
+class RequirableContext(Context):
+    def __init__(self, search_paths, enable_python=False):
+        super(RequirableContext, self).__init__()
+        self.search_paths = search_paths
+        self.evaljs("Duktape.modSearch = dukpy.modSearch;", modSearch=self.require)
+        self.enable_python = True
+
+    def require(self, id_, require, exports, module):
+        # does the module ID begin with 'python/'
+        if self.enable_python and id_.startswith('python/'):
+            pyid = id_[len('python/'):].replace('/', '.')
+            ret = self.require_python(pyid, require, exports, module)
+            if ret:
+                return ret
+
+        for search_path in self.search_paths:
+            # we'll assume here that search_path is relative to cwd
+            # or is an absolute path(!)
+            try:
+                with open(os.path.join(search_path, id_ + '.js')) as f:
+                    return f.read()
+            except IOError:
+                # assume this was probably No such file
+                continue
+
+        raise Exception("Unable to load {}".format(id_))
+
+    def require_python(self, pyid, require, exports, module):
+        try:
+            pymod = importlib.import_module(pyid)
+        except ImportError:
+            return None
+
+        # hack to work around the fact that
+        # JS objects in Python are copies, and don't reflect the state of the object
+        # "in JS land"
+        all_things = getattr(pymod, '__all__', [x for x in dir(pymod) if x and x[0] != '_'])
+        self.evaljs("""
+Duktape._pymodules = Duktape._pymodules || {};
+Duktape._pymodulesins = Duktape._pymodulesins || {};
+
+Duktape._pylastmodule = dukpy.module_name;
+Duktape._pymodules[dukpy.module_name] = dukpy.module;
+Duktape._pymodulesins[dukpy.module_name] = dukpy.module_things;
+""", module_name=pyid, module=pymod, module_things=all_things)
+        return """
+var a = Duktape._pymodulesins[Duktape._pylastmodule];
+for (var i = 0; i < a.length; i++) {
+    var k = a[i];
+    exports[k] = Duktape._pymodules[Duktape._pylastmodule][k];
+}
+"""
+
+
 class JSFunction(object):
     def __init__(self, func_ptr):
         self._func = func_ptr

tests/testjs/testjs.js

@@ -0,0 +1,3 @@
+exports.call = function() {
+	return 'Hello from JS!';
+};

tests/tests_evaljs.py

@@ -1,4 +1,5 @@
 import json
+import os.path
 import dukpy
 from diffreport import report_diff
 
@@ -216,6 +217,23 @@ def call_first_argument_python(a, *args):
         assert ret == 18
 
 
+class TestRequirableContext(object):
+    test_js_dir = os.path.join(os.path.dirname(__file__), 'testjs')
+
+    def test_js_require(self):
+        c = dukpy.RequirableContext([self.test_js_dir])
+        assert c.evaljs("require('testjs').call()") == "Hello from JS!"
+
+    def test_python_require(self):
+        import sys, imp
+        testpy = imp.new_module('testpy')
+        testpy.call = lambda: 'Hello from Python!'
+        testpy.__all__ = ['call']
+        sys.modules['testpy'] = testpy
+        c = dukpy.RequirableContext([], enable_python=True)
+        assert c.evaljs("require('python/testpy').call()") == "Hello from Python!"
+
+
 class TestRegressions(object):
     def test_pyargs_segfault(self):
         for _ in range(1, 10):