Refactor the argspec type checking and add path as a type

lib/ansible/module_utils/basic.py

@@ -380,6 +380,16 @@ class AnsibleModule(object):
 
         self._set_defaults(pre=True)
 
+
+        self._CHECK_ARGUMENT_TYPES_DISPATCHER = {
+                'str': self._check_type_str,
+                'list': self._check_type_list,
+                'dict': self._check_type_dict,
+                'bool': self._check_type_bool,
+                'int': self._check_type_int,
+                'float': self._check_type_float,
+                'path': self._check_type_path,
+            }
         if not bypass_checks:
             self._check_required_arguments()
             self._check_argument_values()
@@ -1021,72 +1031,96 @@ class AnsibleModule(object):
                 return (str, e)
             return str
 
-    def _check_argument_types(self):
-        ''' ensure all arguments have the requested type '''
-        for (k, v) in self.argument_spec.iteritems():
-            wanted = v.get('type', None)
-            if wanted is None:
-                continue
-            if k not in self.params:
-                continue
+    def _check_type_str(self, value):
+        if isinstance(value, basestring):
+            return value
+        # Note: This could throw a unicode error if value's __str__() method
+        # returns non-ascii.  Have to port utils.to_bytes() if that happens
+        return str(value)
 
-            value = self.params[k]
-            is_invalid = False
+    def _check_type_list(self, value):
+        if isinstance(value, list):
+            return value
 
-            try:
-                if wanted == 'str':
-                    if not isinstance(value, basestring):
-                        self.params[k] = str(value)
-                elif wanted == 'list':
-                    if not isinstance(value, list):
         if isinstance(value, basestring):
-                            self.params[k] = value.split(",")
+            return value.split(",")
         elif isinstance(value, int) or isinstance(value, float):
-                            self.params[k] = [ str(value) ]
-                        else:
-                            is_invalid = True
-                elif wanted == 'dict':
-                    if not isinstance(value, dict):
+            return [ str(value) ]
+
+        raise TypeError('%s cannot be converted to a list' % type(value))
+
+    def _check_type_dict(self, value):
+        if isinstance(value, dict):
+            return value
+
         if isinstance(value, basestring):
             if value.startswith("{"):
                 try:
-                                    self.params[k] = json.loads(value)
+                    return json.loads(value)
                 except:
                     (result, exc) = self.safe_eval(value, dict(), include_exceptions=True)
                     if exc is not None:
-                                        self.fail_json(msg="unable to evaluate dictionary for %s" % k)
-                                    self.params[k] = result
+                        raise TypeError('unable to evaluate string as dictionary')
+                    return result
             elif '=' in value:
-                                self.params[k] = dict([x.strip().split("=", 1) for x in value.split(",")])
-                            else:
-                                self.fail_json(msg="dictionary requested, could not parse JSON or key=value")
+                return dict([x.strip().split("=", 1) for x in value.split(",")])
             else:
-                            is_invalid = True
-                elif wanted == 'bool':
-                    if not isinstance(value, bool):
+                raise TypeError("dictionary requested, could not parse JSON or key=value")
+
+        raise TypeError('%s cannot be converted to a dict' % type(value))
+
+    def _check_type_bool(self, value):
+        if isinstance(value, bool):
+            return value
+
         if isinstance(value, basestring):
-                            self.params[k] = self.boolean(value)
-                        else:
-                            is_invalid = True
-                elif wanted == 'int':
-                    if not isinstance(value, int):
+            return self.boolean(value)
+
+        raise TypeError('%s cannot be converted to a bool' % type(value))
+
+    def _check_type_int(self, value):
+        if isinstance(value, int):
+            return value
+
         if isinstance(value, basestring):
-                            self.params[k] = int(value)
-                        else:
-                            is_invalid = True
-                elif wanted == 'float':
-                    if not isinstance(value, float):
+            return int(value)
+
+        raise TypeError('%s cannot be converted to an int' % type(value))
+
+    def _check_type_float(self, value):
+        if isinstance(value, float):
+            return value
+
         if isinstance(value, basestring):
-                            self.params[k] = float(value)
-                        else:
-                            is_invalid = True
-                else:
-                    self.fail_json(msg="implementation error: unknown type %s requested for %s" % (wanted, k))
+            return float(value)
 
-                if is_invalid:
-                    self.fail_json(msg="argument %s is of invalid type: %s, required: %s" % (k, type(value), wanted))
-            except ValueError:
-                self.fail_json(msg="value of argument %s is not of type %s and we were unable to automatically convert" % (k, wanted))
+        raise TypeError('%s cannot be converted to a float' % type(value))
+
+    def _check_type_path(self, value):
+        value = self._check_type_str(value)
+        return os.path.expanduser(os.path.expandvars(value))
+
+
+    def _check_argument_types(self):
+        ''' ensure all arguments have the requested type '''
+        for (k, v) in self.argument_spec.iteritems():
+            wanted = v.get('type', None)
+            if wanted is None:
+                continue
+            if k not in self.params:
+                continue
+
+            value = self.params[k]
+            is_invalid = False
+
+            try:
+                type_checker = self._CHECK_ARGUMENT_TYPES_DISPATCHER[wanted]
+            except KeyError:
+                self.fail_json(msg="implementation error: unknown type %s requested for %s" % (wanted, k))
+            try:
+                self.params[k] = type_checker(value)
+            except (TypeError, ValueError):
+                self.fail_json(msg="argument %s is of type %s and we were unable to convert to %s" % (k, type(value), wanted))
 
     def _set_defaults(self, pre=True):
         for (k,v) in self.argument_spec.iteritems():