Add support for enum with one value (#666)

* Add databricks, fix several issues

* Fixed a completer related issue and add support for credential

* Add two m4 configuration and fix some issues

* Add support for enum with one value

Author: dolauli

powershell/llcsharp/schema/schema-resolver.ts

@@ -231,7 +231,7 @@ export class NewSchemaDefinitionResolver {
       case SchemaType.Constant:
         switch ((<ConstantSchema>schema).valueType.type) {
           case SchemaType.String:
-            return new NewEnumImplementation(<StringSchema>schema, required);
+            return new NewString(schema, required);
           case SchemaType.DateTime:
             if ((<any>schema).valueType.format === StringFormat.DateTimeRfc1123) {
               return new NewDateTime1123(<DateTimeSchema>schema, required);

powershell/plugins/plugin-create-inline-properties.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { codeModelSchema, CodeModel, ObjectSchema, GroupSchema, isObjectSchema, SchemaType, GroupProperty, ParameterLocation, Operation, Parameter, ImplementationLocation, OperationGroup, Request, SchemaContext } from '@azure-tools/codemodel';
+import { codeModelSchema, CodeModel, ObjectSchema, ConstantSchema, GroupSchema, isObjectSchema, SchemaType, GroupProperty, ParameterLocation, Operation, Parameter, ImplementationLocation, OperationGroup, Request, SchemaContext } from '@azure-tools/codemodel';
 //import { VirtualParameter } from '@azure-tools/codemodel-v3';
 import { getPascalIdentifier, removeSequentialDuplicates, pascalCase, fixLeadingNumber, deconstruct, selectName, EnglishPluralizationService, serialize } from '@azure-tools/codegen';
 import { length, values, } from '@azure-tools/linq';
@@ -270,6 +270,11 @@ function createVirtualProperties(schema: ObjectSchema, stack: Array<string>, thr
       alias: [],
       required: property.required || property.language.default.required
     });
+    // dolauli, set constant value and make it readonly, if it is constant
+    if (property.schema.type === SchemaType.Constant) {
+      property.language.default.readOnly = true;
+      property.language.default.constantValue = (<ConstantSchema>property.schema).value.value;
+    }
   }
 
   // resolve name collisions.