[BUG][KOTLIN] Fix for reserved enum name

src/main/java/io/swagger/codegen/v3/generators/kotlin/AbstractKotlinCodegen.java

@@ -1,6 +1,8 @@
 package io.swagger.codegen.v3.generators.kotlin;
 
 import com.github.jknack.handlebars.helper.ConditionalHelpers;
+import com.samskivert.mustache.Escapers;
+import com.samskivert.mustache.Mustache;
 import io.swagger.codegen.v3.CliOption;
 import io.swagger.codegen.v3.CodegenConstants;
 import io.swagger.codegen.v3.CodegenModel;
@@ -513,9 +515,28 @@ public String toVarName(String name) {
 
     @Override
     public String toEnumName(CodegenProperty property) {
+        //Need to handle case when property name is escaped (possible reserved word)
+        if (property.name.startsWith("`")) {
+            return String.format("`%s", StringUtils.capitalize(property.name.substring(1)));
+        }
         return StringUtils.capitalize(property.name);
     }
 
+    @Override
+    public Mustache.Compiler processCompiler(Mustache.Compiler compiler) {
+        Mustache.Escaper KOTLIN = new Mustache.Escaper() {
+            @Override
+            public String escape(String text) {
+                if (text.startsWith("`") && text.endsWith("`")) {
+                    String unescaped = text.substring(1, text.length() - 1);
+                    return "`" + Escapers.HTML.escape(unescaped) + "`";
+                }
+                return Escapers.HTML.escape(text);
+            }
+        };
+        return compiler.withEscaper(KOTLIN);
+    }
+
     @Override
     public void addHandlebarHelpers(Handlebars handlebars) {
         super.addHandlebarHelpers(handlebars);

src/test/java/io/swagger/codegen/v3/generators/kotlin/KotlinClientCodegenModelTest.java

@@ -4,7 +4,6 @@
 import io.swagger.codegen.v3.CodegenConstants;
 import io.swagger.codegen.v3.CodegenModel;
 import io.swagger.codegen.v3.CodegenProperty;
-import io.swagger.codegen.v3.generators.AbstractCodegenTest;
 import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.media.ArraySchema;
@@ -20,8 +19,6 @@
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
-import java.util.HashMap;
-
 import static io.swagger.codegen.v3.generators.handlebars.ExtensionHelper.getBooleanValue;
 
 @SuppressWarnings("static-method")
@@ -283,6 +280,24 @@ public void sanitizeEnumVarNames(final String name, final String expectedName) {
 
     }
 
+    @DataProvider
+    public static Object[][] enumClassNames() {
+        return new Object[][] {
+            {"name1", "Name1"},
+            {"A", "A"},
+            {"NAME2", "NAME2"},
+            {"`return`", "`Return`"},
+        };
+    }
+
+    @Test(dataProvider = "enumClassNames", description = "sanitize Enum class names")
+    public void capitalizeEnumName(final String name, final String expectedName) {
+        final KotlinClientCodegen codegen = new KotlinClientCodegen();
+        CodegenProperty property = new CodegenProperty();
+        property.setName(name);
+        Assert.assertEquals(codegen.toEnumName(property), expectedName);
+    }
+
     private static class ModelNameTest {
         private String expectedName;
         private String expectedClassName;
@@ -297,4 +312,4 @@ private ModelNameTest(String expectedName, String expectedClassName) {
             this.expectedClassName = expectedClassName;
         }
     }
-}
+}