Add ability to dynamically import namespaces from types in the tsd cl…

…ient (#235)

* Add ability to dynamically import namespaces from types in the tsd client

stone/backends/tsd_client.py

@@ -67,6 +67,29 @@
     help=('Wraps the response in a response class')
 )
 
+_cmdline_parser.add_argument(
+    '--import-namespaces',
+    default=False,
+    action='store_true',
+    help=('Adds an import statement at the top of the file to import each '
+          'namespace from the as a named import. Must be used in conjunction '
+          'with the --export-namespaces command when generating the ts_types.')
+)
+_cmdline_parser.add_argument(
+    '--import-template-string',
+    type=str,
+    default='IMPORT',
+    help=('The name of the template string to replace with import statement. '
+          'Defaults to IMPORT, which replaces the string /*IMPORT*/ with import.')
+)
+_cmdline_parser.add_argument(
+    '--types-file',
+    type=str,
+    default='',
+    help=('If using the --import-namespaces flag, this is the file that contains '
+          'the named exports to import here.')
+)
+
 _header = """\
 // Auto-generated by Stone, do not modify.
 """
@@ -103,10 +126,32 @@ def generate(self, api):
             t_end = len(template)
             t_ends_with_newline = template[t_end - 1] == '\n'
 
-            self.emit_raw(template[0:r_start] + ('\n' if not r_ends_with_newline else ''))
+            if self.args.import_namespaces:
+                import_template_string = self.args.import_template_string
+                import_from_file = self.args.types_file
+                # /*IMPORT*/
+                i_match = re.search("/\\*%s\\*/" % (import_template_string), template)
+                if not i_match:
+                    raise AssertionError(
+                        'Missing /*%s*/ in TypeScript template file.' % import_template_string)
+                i_start = i_match.start()
+                i_end = i_match.end()
+                i_ends_with_newline = template[i_end - 1] == '\n'
+                t_end = len(template)
+                t_ends_with_newline = template[t_end - 1] == '\n'
+
+                self.emit_raw(template[0:i_start] + ('\n' if not i_ends_with_newline else ''))
+                self._generate_import(api, import_from_file)
+                self.emit_raw(template[i_end + 1:r_end] + ('\n' if not r_ends_with_newline else ''))
+            else:
+                self.emit_raw(template[0:r_start] + ('\n' if not r_ends_with_newline else ''))
             self._generate_routes(api, spaces_per_indent, indent_level)
             self.emit_raw(template[r_end + 1:t_end] + ('\n' if not t_ends_with_newline else ''))
 
+    def _generate_import(self, api, type_file):
+        namespaces = ", ".join(map(lambda namespace: namespace.name, api.namespaces.values()))
+        self.emit("import { %s } from '%s';" % (namespaces, type_file))
+
     def _generate_routes(self, api, spaces_per_indent, indent_level):
         with self.indent(dent=spaces_per_indent * (indent_level + 1)):
             for namespace in api.namespaces.values():