[python] Adds python oneOf/anyOf models + tests (OpenAPITools#5341)

* Adds oneOf + anyOf schemas, models and tests to python-experimental

* Adds setUpClass and tearDownClass

* Removes newline in method_init_shared.mustache

* Regenerated v3 spec sample for python-experimental

* Fxes test for discard_unknown_keys

* Moves new models into existing spec, regen python-exp and go-exp

* Also fix python-exp windows file

bin/openapi3/windows/python-experimental-petstore.bat

@@ -5,6 +5,6 @@ If Not Exist %executable% (
 )
 
 REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M
-set ags=generate -i modules\openapi-generator\src\test\resources\3_0\petstore-with-fake-endpoints-models-for-testing.yaml -g python-experimental -o samples\openapi3\client\petstore\python-experimental --additional-properties packageName=petstore_api
+set ags=generate -i modules\openapi-generator\src\test\resources\3_0\petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml -g python-experimental -o samples\openapi3\client\petstore\python-experimental --additional-properties packageName=petstore_api
 
 java %JAVA_OPTS% -jar %executable% %ags%

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientExperimentalCodegen.java

@@ -706,6 +706,56 @@ public void postProcessParameter(CodegenParameter p) {
         }
     }
 
+    private void addNullDefaultToOneOfAnyOfReqProps(Schema schema, CodegenModel result){
+        // for composed schema models, if the required properties are only from oneOf or anyOf models
+        // give them a nulltype.Null so the user can omit including them in python
+        ComposedSchema cs = (ComposedSchema) schema;
+
+        // these are the properties that are from properties in self cs or cs allOf
+        Map<String, Schema> selfProperties = new LinkedHashMap<String, Schema>();
+        List<String> selfRequired = new ArrayList<String>();
+
+        // these are the properties that are from properties in cs oneOf or cs anyOf
+        Map<String, Schema> otherProperties = new LinkedHashMap<String, Schema>();
+        List<String> otherRequired = new ArrayList<String>();
+
+        List<Schema> oneOfanyOfSchemas = new ArrayList<>();
+        List<Schema> oneOf = cs.getOneOf();
+        if (oneOf != null) {
+            oneOfanyOfSchemas.addAll(oneOf);
+        }
+        List<Schema> anyOf = cs.getAnyOf();
+        if (anyOf != null) {
+            oneOfanyOfSchemas.addAll(anyOf);
+        }
+        for (Schema sc: oneOfanyOfSchemas) {
+            Schema refSchema = ModelUtils.getReferencedSchema(this.openAPI, sc);
+            addProperties(otherProperties, otherRequired, refSchema);
+        }
+        Set<String> otherRequiredSet = new HashSet<String>(otherRequired);
+
+        List<Schema> allOf = cs.getAllOf();
+        if ((schema.getProperties() != null && !schema.getProperties().isEmpty()) || allOf != null) {
+            // NOTE: this function also adds the allOf propesrties inside schema
+            addProperties(selfProperties, selfRequired, schema);
+        }
+        if (result.discriminator != null) {
+            selfRequired.add(result.discriminator.getPropertyBaseName());
+        }
+        Set<String> selfRequiredSet = new HashSet<String>(selfRequired);
+
+        List<CodegenProperty> reqVars = result.getRequiredVars();
+        if (reqVars != null) {
+            for (CodegenProperty cp: reqVars) {
+                String propName = cp.baseName;
+                if (otherRequiredSet.contains(propName) && !selfRequiredSet.contains(propName)) {
+                    // if var is in otherRequiredSet and is not in selfRequiredSet and is in result.requiredVars
+                    // then set it to nullable because the user doesn't have to give a value for it
+                    cp.setDefaultValue("nulltype.Null");
+                }
+            }
+        }
+    }
 
     /**
      * Convert OAS Model object to Codegen Model object
@@ -806,6 +856,11 @@ public CodegenModel fromModel(String name, Schema schema) {
         if (result.imports.contains(result.classname)) {
             result.imports.remove(result.classname);
         }
+
+        if (result.requiredVars.size() > 0 && (result.oneOf.size() > 0 || result.anyOf.size() > 0)) {
+            addNullDefaultToOneOfAnyOfReqProps(schema, result);
+        }
+
         return result;
     }
 

modules/openapi-generator/src/main/resources/python/python-experimental/model.mustache

@@ -7,6 +7,7 @@ import re  # noqa: F401
 import sys  # noqa: F401
 
 import six  # noqa: F401
+import nulltype  # noqa: F401
 
 from {{packageName}}.model_utils import (  # noqa: F401
     ModelComposed,

modules/openapi-generator/src/main/resources/python/python-experimental/model_templates/method_init_composed.mustache

@@ -17,11 +17,18 @@
             '_from_server': _from_server,
             '_configuration': _configuration,
         }
-        model_args = {
+        required_args = {
 {{#requiredVars}}
             '{{name}}': {{name}},
 {{/requiredVars}}
         }
+        # remove args whose value is Null because they are unset
+        required_arg_names = list(required_args.keys())
+        for required_arg_name in required_arg_names:
+            if required_args[required_arg_name] is nulltype.Null:
+                del required_args[required_arg_name]
+        model_args = {}
+        model_args.update(required_args)
         model_args.update(kwargs)
         composed_info = validate_get_composed_info(
             constant_args, model_args, self)
@@ -30,9 +37,8 @@
         self._additional_properties_model_instances = composed_info[2]
         unused_args = composed_info[3]
 
-{{#requiredVars}}
-        self.{{name}} = {{name}}
-{{/requiredVars}}
+        for var_name, var_value in required_args.items():
+            setattr(self, var_name, var_value)
         for var_name, var_value in six.iteritems(kwargs):
             if var_name in unused_args and \
                         self._configuration is not None and \

modules/openapi-generator/src/main/resources/python/python-experimental/model_templates/method_init_shared.mustache

@@ -1,11 +1,23 @@
     def __init__(self{{#requiredVars}}{{^defaultValue}}, {{name}}{{/defaultValue}}{{/requiredVars}}{{#requiredVars}}{{#defaultValue}}, {{name}}={{{defaultValue}}}{{/defaultValue}}{{/requiredVars}}, _check_type=True, _from_server=False, _path_to_item=(), _configuration=None, **kwargs):  # noqa: E501
         """{{classname}} - a model defined in OpenAPI
 
-{{#requiredVars}}{{^hasMore}}        Args:{{/hasMore}}{{/requiredVars}}{{#requiredVars}}{{^defaultValue}}
-            {{name}} ({{{dataType}}}):{{#description}} {{description}}{{/description}}{{/defaultValue}}{{/requiredVars}}{{#requiredVars}}{{^hasMore}}
-{{/hasMore}}{{/requiredVars}}
-        Keyword Args:{{#requiredVars}}{{#defaultValue}}
-            {{name}} ({{{dataType}}}):{{#description}} {{description}}.{{/description}} defaults to {{{defaultValue}}}, must be one of [{{{defaultValue}}}]  # noqa: E501{{/defaultValue}}{{/requiredVars}}
+{{#requiredVars}}
+{{#-first}}
+        Args:
+{{/-first}}
+{{^defaultValue}}
+            {{name}} ({{{dataType}}}):{{#description}} {{description}}{{/description}}
+{{/defaultValue}}
+{{#-last}}
+
+{{/-last}}
+{{/requiredVars}}
+        Keyword Args:
+{{#requiredVars}}
+{{#defaultValue}}
+            {{name}} ({{{dataType}}}):{{#description}} {{description}}.{{/description}} defaults to {{{defaultValue}}}{{#allowableValues}}, must be one of [{{#enumVars}}{{{value}}}, {{/enumVars}}]{{/allowableValues}}  # noqa: E501
+{{/defaultValue}}
+{{/requiredVars}}
             _check_type (bool): if True, values for parameters in openapi_types
                                 will be type checked and a TypeError will be
                                 raised if the wrong type is input.
@@ -18,8 +30,10 @@
             _configuration (Configuration): the instance to use when
                                 deserializing a file_type parameter.
                                 If passed, type conversion is attempted
-                                If omitted no type conversion is done.{{#optionalVars}}
-            {{name}} ({{{dataType}}}):{{#description}} {{description}}.{{/description}} [optional]{{#defaultValue}} if omitted the server will use the default value of {{{defaultValue}}}{{/defaultValue}}  # noqa: E501{{/optionalVars}}
+                                If omitted no type conversion is done.
+{{#optionalVars}}
+            {{name}} ({{{dataType}}}):{{#description}} {{description}}.{{/description}} [optional]{{#defaultValue}} if omitted the server will use the default value of {{{defaultValue}}}{{/defaultValue}}  # noqa: E501
+{{/optionalVars}}
         """
 
         self._data_store = {}

modules/openapi-generator/src/main/resources/python/python-experimental/model_templates/methods_setattr_getattr_composed.mustache

@@ -41,21 +41,23 @@
         if self._path_to_item:
             path_to_item.extend(self._path_to_item)
         path_to_item.append(name)
+        values = set()
         if model_instances:
-            values = set()
             for model_instance in model_instances:
                 if name in model_instance._data_store:
                     values.add(model_instance._data_store[name])
-            if len(values) == 1:
-                return list(values)[0]
+        len_values = len(values)
+        if len_values == 0:
+            raise ApiKeyError(
+                "{0} has no key '{1}'".format(type(self).__name__, name),
+                path_to_item
+            )
+        elif len_values == 1:
+            return list(values)[0]
+        elif len_values > 1:
             raise ApiValueError(
                 "Values stored for property {0} in {1} difffer when looking "
                 "at self and self's composed instances. All values must be "
                 "the same".format(name, type(self).__name__),
                 path_to_item
-            )
-
-        raise ApiKeyError(
-            "{0} has no key '{1}'".format(type(self).__name__, name),
-            path_to_item
-        )
+            )

modules/openapi-generator/src/main/resources/python/python-experimental/model_utils.mustache

@@ -828,7 +828,7 @@ def model_to_dict(model_instance, serialize=True):
 
     model_instances = [model_instance]
     if model_instance._composed_schemas() is not None:
-        model_instances = model_instance._composed_instances
+        model_instances.extend(model_instance._composed_instances)
     for model_instance in model_instances:
         for attr, value in six.iteritems(model_instance._data_store):
             if serialize:
@@ -951,12 +951,12 @@ def get_oneof_instance(self, model_args, constant_args):
             used to make instances
 
     Returns
-        oneof_instance (instance)
+        oneof_instance (instance/None)
     """
-    oneof_instance = None
     if len(self._composed_schemas()['oneOf']) == 0:
-        return oneof_instance
+        return None
 
+    oneof_instances = []
     for oneof_class in self._composed_schemas()['oneOf']:
         # transform js keys to python keys in fixed_model_args
         fixed_model_args = change_keys_js_to_python(
@@ -969,20 +969,30 @@ def get_oneof_instance(self, model_args, constant_args):
             if var_name in fixed_model_args:
                 kwargs[var_name] = fixed_model_args[var_name]
 
+        # do not try to make a model with no input args
+        if len(kwargs) == 0:
+            continue
+
         # and use it to make the instance
         kwargs.update(constant_args)
         try:
             oneof_instance = oneof_class(**kwargs)
-            break
+            oneof_instances.append(oneof_instance)
         except Exception:
             pass
-    if oneof_instance is None:
+    if len(oneof_instances) == 0:
         raise ApiValueError(
             "Invalid inputs given to generate an instance of %s. Unable to "
             "make any instances of the classes in oneOf definition." %
             self.__class__.__name__
         )
-    return oneof_instance
+    elif len(oneof_instances) > 1:
+        raise ApiValueError(
+            "Invalid inputs given to generate an instance of %s. Multiple "
+            "oneOf instances were generated when a max of one is allowed." %
+            self.__class__.__name__
+        )
+    return oneof_instances[0]
 
 
 def get_anyof_instances(self, model_args, constant_args):
@@ -1012,6 +1022,10 @@ def get_anyof_instances(self, model_args, constant_args):
             if var_name in fixed_model_args:
                 kwargs[var_name] = fixed_model_args[var_name]
 
+        # do not try to make a model with no input args
+        if len(kwargs) == 0:
+            continue
+
         # and use it to make the instance
         kwargs.update(constant_args)
         try:

modules/openapi-generator/src/main/resources/python/python-experimental/requirements.mustache

@@ -1,3 +1,4 @@
+nulltype
 certifi >= 14.05.14
 future; python_version<="2.7"
 six >= 1.10

modules/openapi-generator/src/main/resources/python/python-experimental/setup.mustache

@@ -21,6 +21,7 @@ REQUIRES = [
   "six >= 1.10",
   "certifi",
   "python-dateutil",
+  "nulltype",
 {{#asyncio}}
   "aiohttp >= 3.0.0",
 {{/asyncio}}

modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml

@@ -1779,3 +1779,82 @@ components:
       additionalProperties:
         type: object
         nullable: true
+    fruit:
+      properties:
+        color:
+          type: string
+      oneOf:
+        - $ref: '#/components/schemas/apple'
+        - $ref: '#/components/schemas/banana'
+    apple:
+      type: object
+      properties:
+        cultivar:
+          type: string
+    banana:
+      type: object
+      properties:
+        lengthCm:
+          type: number
+    mammal:
+      oneOf:
+        - $ref: '#/components/schemas/whale'
+        - $ref: '#/components/schemas/zebra'
+      discriminator:
+        propertyName: className
+        mapping:
+          whale: '#/components/schemas/whale'
+          zebra: '#/components/schemas/zebra'
+    whale:
+      type: object
+      properties:
+        hasBaleen:
+          type: boolean
+        hasTeeth:
+          type: boolean
+        className:
+          type: string
+      required:
+        - className
+    zebra:
+      type: object
+      properties:
+        type:
+          type: string
+          enum:
+            - plains
+            - mountain
+            - grevys
+        className:
+          type: string
+      required:
+        - className
+    gmFruit:
+       properties:
+          color:
+             type: string
+       anyOf:
+          - $ref: '#/components/schemas/apple'
+          - $ref: '#/components/schemas/banana'
+    fruitReq:
+       oneOf:
+          - $ref: '#/components/schemas/appleReq'
+          - $ref: '#/components/schemas/bananaReq'
+    appleReq:
+      type: object
+      properties:
+        cultivar:
+          type: string
+        mealy:
+          type: boolean
+      required:
+        - cultivar
+    bananaReq:
+      type: object
+      properties:
+        lengthCm:
+          type: number
+        sweet:
+          type: boolean
+      required:
+        - lengthCm