Experimental support for 'require' in js code

dukpy/evaljs.py

@@ -1,4 +1,8 @@
+from __future__ import print_function
 import json
+import os
+
+from dukpy.module_loader import JSModuleLoader
 from . import _dukpy
 
 try:
@@ -16,19 +20,17 @@ except NameError:  # pragma: no cover
 class JSInterpreter(object):
     """JavaScript Interpreter"""
     def __init__(self):
+        self._loader = JSModuleLoader()
         self._ctx = _dukpy.create_context()
         self._funcs = {}
 
-    def _adapt_code(self, code):
-        def _read_files(f):
-            if hasattr(f, 'read'):
-                return f.read()
-            else:
-                return f
-        code = _read_files(code)
-        if not isinstance(code, string_types) and hasattr(code, '__iter__'):
-            code = ';\n'.join(map(_read_files, code))
-        return code
+        self._init_process()
+        self._init_console()
+        self._init_require()
+
+    @property
+    def loader(self):
+        return self._loader
 
     def evaljs(self, code, **kwargs):
         """Runs JavaScript code in the context of the interpreter.
@@ -73,6 +75,42 @@ class JSInterpreter(object):
         if ret is not None:
             return json.dumps(ret).encode('utf-8')
 
+    def _init_process(self):
+        self.evaljs("process = {}; process.env = dukpy.environ", environ=dict(os.environ))
+
+    def _init_console(self):
+        self.export_function('dukpy.print', print)
+        self.evaljs("""
+        ;console = {
+            log: function() {
+                call_python('dukpy.print', Array.prototype.join.call(arguments, ' '));
+            }
+        };
+        """)
+
+    def _init_require(self):
+        self.export_function('dukpy.lookup_module', self._loader.load)
+        self.evaljs("""
+        ;Duktape.modSearch = function (id, require, exports, module) {
+            var m = call_python('dukpy.lookup_module', id);
+            if (!m)
+                throw new Error('cannot find module: ' + id);
+            return m;
+        };
+""")
+
+    def _adapt_code(self, code):
+        def _read_files(f):
+            if hasattr(f, 'read'):
+                return f.read()
+            else:
+                return f
+
+        code = _read_files(code)
+        if not isinstance(code, string_types) and hasattr(code, '__iter__'):
+            code = ';\n'.join(map(_read_files, code))
+        return code
+
 
 def evaljs(code, **kwargs):
     """Evaluates the given ``code`` as JavaScript and returns the result"""

dukpy/module_loader.py

@@ -0,0 +1,65 @@
+# -*- coding: utf-8 -*-
+import json
+import os
+
+
+class JSModuleLoader(object):
+    """Manages finding and loading JS modules in CommonJS format.
+
+    This allows to import a module from JSInterpreter using the
+    `require('modulename')` command.
+
+    To register additional paths where to look for modules use
+    the `JSModuleLoader.register_path` method.
+    """
+    def __init__(self):
+        self._paths = []
+        self.register_path(os.path.join(os.path.dirname(__file__), 'jsmodules'))
+        self.register_path(os.getcwd())
+
+    def register_path(self, path):
+        """Registers a directory where to look for modules.
+
+        By default only modules relative to current path are found.
+        """
+        self._paths.insert(0, os.path.abspath(path))
+
+    def lookup(self, module_name):
+        """Searches for a file providing given module."""
+        for search_path in self._paths:
+            module_path = os.path.join(search_path, module_name)
+            module_file = self._lookup(module_path)
+            if module_file:
+                return module_file
+
+    def load(self, module_name):
+        """Returns source code of the given module."""
+        path = self.lookup(module_name)
+        if path:
+            with open(path, 'rb') as f:
+                return f.read()
+
+    def _lookup(self, module_path):
+        # Module is a plain .js file
+        for path in (module_path, os.path.extsep.join((module_path, 'js'))):
+            if os.path.exists(path) and os.path.isfile(path):
+                return path
+
+        # Module is a package
+        package = os.path.join(module_path, os.path.extsep.join(('package', 'json')))
+        try:
+            with open(package) as f:
+                package = json.load(f)
+        except IOError:
+            pass
+        else:
+            package_main = package.get('main')
+            if package_main:
+                path = self._lookup(os.path.join(module_path, package_main))
+                if path:
+                    return path
+
+        # Module is directory with index.js inside
+        indexjs = os.path.join(module_path, os.path.extsep.join(('index', 'js')))
+        if os.path.exists(indexjs):
+            return indexjs

setup.py

@@ -8,7 +8,9 @@ except IOError:
     README = ''
 
 duktape = Extension('dukpy._dukpy',
-                    define_macros=[('DUK_OPT_DEEP_C_STACK', '1')],
+                    define_macros=[('DUK_OPT_DEEP_C_STACK', '1'),
+                                   ('DUK_OPT_NONSTD_REGEXP_DOLLAR_ESCAPE', '1'),
+                                   ('DUK_OPT_OCTAL_SUPPORT', '1')],
                     sources=[os.path.join('src', 'duktape', 'duktape.c'),
                              os.path.join('src','_support.c'),
                              os.path.join('src','pyduktape.c')],

tests/tests_jsinterpreter.py

@@ -1,4 +1,5 @@
 import dukpy
+from diffreport import report_diff
 
 
 class TestJSInterpreter(object):
@@ -16,4 +17,16 @@ class TestJSInterpreter(object):
         interpreter = dukpy.JSInterpreter()
         interpreter.export_function('say_hello', _say_hello)
         res = interpreter.evaljs("call_python('say_hello', 3, 'world')")
-        assert res == 'Hello world world world', res
+        assert res == 'Hello world world world', res
+
+    def test_module_loader(self):
+        interpreter = dukpy.JSInterpreter()
+        res = interpreter.evaljs('''
+    babel = require('babel-6.4.4.min');
+    babel.transform(dukpy.es6code, {presets: ["es2015"]}).code;
+''', es6code='let i=5;')
+
+        expected = '''"use strict";
+
+var i = 5;'''
+        assert res == expected, report_diff(expected, res)