[kotlin] support selection of datelibrary (#7054)

* [kotlin] support selection of datelibrary

* remove additional property from string

* replace string with boolean

bin/kotlin-client-petstore.sh

@@ -26,6 +26,6 @@ fi
 
 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="generate -t modules/swagger-codegen/src/main/resources/kotlin-client -i modules/swagger-codegen/src/test/resources/2_0/petstore.yaml -l kotlin --artifact-id kotlin-petstore-client -o samples/client/petstore/kotlin $@"
+ags="generate -t modules/swagger-codegen/src/main/resources/kotlin-client -i modules/swagger-codegen/src/test/resources/2_0/petstore.yaml -l kotlin --artifact-id kotlin-petstore-client -D dateLibrary=java8 -o samples/client/petstore/kotlin $@"
 
 java ${JAVA_OPTS} -jar ${executable} ${ags}

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/KotlinClientCodegen.java

@@ -9,8 +9,32 @@ import java.io.File;
 
 public class KotlinClientCodegen extends AbstractKotlinCodegen {
 
+    public static final String DATE_LIBRARY = "dateLibrary";
+
+    protected String groupId = "io.swagger";
+    protected String artifactId = "kotlin-client";
+    protected String artifactVersion = "1.0.0";
+    protected String sourceFolder = "src/main/kotlin";
+    protected String packageName = "io.swagger.client";
+    protected String apiDocPath = "docs/";
+    protected String modelDocPath = "docs/";
+    protected CodegenConstants.ENUM_PROPERTY_NAMING_TYPE enumPropertyNaming = CodegenConstants.ENUM_PROPERTY_NAMING_TYPE.camelCase;
     static Logger LOGGER = LoggerFactory.getLogger(KotlinClientCodegen.class);
 
+    protected String dateLibrary = DateLibrary.JAVA8.value;
+
+    public enum DateLibrary {
+        STRING("string"),
+        THREETENBP("threetenbp"),
+        JAVA8("java8");
+
+        public final String value;
+
+        DateLibrary(String value) {
+            this.value = value;
+        }
+    }
+
     /**
      * Constructs an instance of `KotlinClientCodegen`.
      */
@@ -28,6 +52,14 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
         embeddedTemplateDir = templateDir = "kotlin-client";
         apiPackage = packageName + ".apis";
         modelPackage = packageName + ".models";
+
+        CliOption dateLibrary = new CliOption(DATE_LIBRARY, "Option. Date library to use");
+        Map<String, String> dateOptions = new HashMap<>();
+        dateOptions.put(DateLibrary.THREETENBP.value, "Threetenbp");
+        dateOptions.put(DateLibrary.STRING.value, "String");
+        dateOptions.put(DateLibrary.JAVA8.value, "Java 8 native JSR310");
+        dateLibrary.setEnum(dateOptions);
+        cliOptions.add(dateLibrary);
     }
 
     public CodegenType getTag() {
@@ -42,10 +74,33 @@ public class KotlinClientCodegen extends AbstractKotlinCodegen {
         return "Generates a kotlin client.";
     }
 
+    public void setDateLibrary(String library) {
+        this.dateLibrary = library;
+    }
+
     @Override
     public void processOpts() {
         super.processOpts();
 
+        if (additionalProperties.containsKey(DATE_LIBRARY)) {
+            setDateLibrary(additionalProperties.get(DATE_LIBRARY).toString());
+        }
+
+        if (DateLibrary.THREETENBP.value.equals(dateLibrary)) {
+            additionalProperties.put(DateLibrary.THREETENBP.value, true);
+            typeMapping.put("date", "LocalDate");
+            typeMapping.put("DateTime", "LocalDateTime");
+            importMapping.put("LocalDate", "org.threeten.bp.LocalDate");
+            importMapping.put("LocalDateTime", "org.threeten.bp.LocalDateTime");
+        } else if (DateLibrary.STRING.value.equals(dateLibrary)) {
+            typeMapping.put("date-time", "kotlin.String");
+            typeMapping.put("date", "kotlin.String");
+            typeMapping.put("Date", "kotlin.String");
+            typeMapping.put("DateTime", "kotlin.String");
+        } else if (DateLibrary.JAVA8.value.equals(dateLibrary)) {
+            additionalProperties.put(DateLibrary.JAVA8.value, true);
+        }
+
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
         supportingFiles.add(new SupportingFile("build.gradle.mustache", "", "build.gradle"));

modules/swagger-codegen/src/test/java/io/swagger/codegen/kotlin/KotlinClientCodegenModelTest.java

@@ -89,6 +89,66 @@ public class KotlinClientCodegenModelTest {
         Assert.assertTrue(property3.isNotContainer);
     }
 
+    @Test(description = "convert a simple model: threetenbp")
+    public void selectDateLibraryAsThreetenbp() {
+        final Model model = getSimpleModel();
+        final KotlinClientCodegen codegen = new KotlinClientCodegen();
+        codegen.setDateLibrary(KotlinClientCodegen.DateLibrary.THREETENBP.value);
+        codegen.processOpts();
+
+        final CodegenModel cm = codegen.fromModel("sample", model);
+
+        final CodegenProperty property3 = cm.vars.get(2);
+        Assert.assertEquals(property3.baseName, "createdAt");
+        Assert.assertEquals(property3.datatype, "org.threeten.bp.LocalDateTime");
+        Assert.assertEquals(property3.name, "createdAt");
+        Assert.assertEquals(property3.defaultValue, "null");
+        Assert.assertEquals(property3.baseType, "org.threeten.bp.LocalDateTime");
+        Assert.assertFalse(property3.hasMore);
+        Assert.assertFalse(property3.required);
+        Assert.assertTrue(property3.isNotContainer);
+    }
+
+    @Test(description = "convert a simple model: date string")
+    public void selectDateLibraryAsString() {
+        final Model model = getSimpleModel();
+        final KotlinClientCodegen codegen = new KotlinClientCodegen();
+        codegen.setDateLibrary(KotlinClientCodegen.DateLibrary.STRING.value);
+        codegen.processOpts();
+
+        final CodegenModel cm = codegen.fromModel("sample", model);
+
+        final CodegenProperty property3 = cm.vars.get(2);
+        Assert.assertEquals(property3.baseName, "createdAt");
+        Assert.assertEquals(property3.datatype, "kotlin.String");
+        Assert.assertEquals(property3.name, "createdAt");
+        Assert.assertEquals(property3.defaultValue, "null");
+        Assert.assertEquals(property3.baseType, "kotlin.String");
+        Assert.assertFalse(property3.hasMore);
+        Assert.assertFalse(property3.required);
+        Assert.assertTrue(property3.isNotContainer);
+    }
+
+    @Test(description = "convert a simple model: date java8")
+    public void selectDateLibraryAsJava8() {
+        final Model model = getSimpleModel();
+        final KotlinClientCodegen codegen = new KotlinClientCodegen();
+        codegen.setDateLibrary(KotlinClientCodegen.DateLibrary.JAVA8.value);
+        codegen.processOpts();
+
+        final CodegenModel cm = codegen.fromModel("sample", model);
+
+        final CodegenProperty property3 = cm.vars.get(2);
+        Assert.assertEquals(property3.baseName, "createdAt");
+        Assert.assertEquals(property3.datatype, "java.time.LocalDateTime");
+        Assert.assertEquals(property3.name, "createdAt");
+        Assert.assertEquals(property3.defaultValue, "null");
+        Assert.assertEquals(property3.baseType, "java.time.LocalDateTime");
+        Assert.assertFalse(property3.hasMore);
+        Assert.assertFalse(property3.required);
+        Assert.assertTrue(property3.isNotContainer);
+    }
+
     @Test(description = "convert a model with array property to default kotlin.Array")
     public void arrayPropertyTest() {
         final Model model = getArrayTestModel();
@@ -113,6 +173,7 @@ public class KotlinClientCodegenModelTest {
         Assert.assertFalse(property.required);
         Assert.assertTrue(property.isContainer);
     }
+
     @Test(description = "convert a model with a map property")
     public void mapPropertyTest() {
         final Model model = getMapModel();

modules/swagger-codegen/src/test/java/io/swagger/codegen/kotlin/KotlinClientCodegenOptionsTest.java

@@ -38,6 +38,7 @@ public class KotlinClientCodegenOptionsTest extends AbstractOptionsTest {
             times = 1;
             codegen.setEnumPropertyNaming(KotlinClientCodegenOptionsProvider.ENUM_PROPERTY_NAMING);
             times = 1;
+            codegen.setDateLibrary(KotlinClientCodegenOptionsProvider.DATE_LIBRARY);
         }};
     }
 }

modules/swagger-codegen/src/test/java/io/swagger/codegen/options/KotlinClientCodegenOptionsProvider.java

@@ -3,6 +3,7 @@ package io.swagger.codegen.options;
 import io.swagger.codegen.CodegenConstants;
 
 import com.google.common.collect.ImmutableMap;
+import io.swagger.codegen.languages.KotlinClientCodegen;
 
 import java.util.Map;
 
@@ -13,6 +14,7 @@ public class KotlinClientCodegenOptionsProvider implements OptionsProvider {
     public static final String GROUP_ID = "io.swagger.tests";
     public static final String SOURCE_FOLDER = "./generated/kotlin";
     public static final String ENUM_PROPERTY_NAMING = "camelCase";
+    public static final String DATE_LIBRARY = KotlinClientCodegen.DateLibrary.JAVA8.value;
 
     @Override
     public String getLanguage() {
@@ -29,6 +31,7 @@ public class KotlinClientCodegenOptionsProvider implements OptionsProvider {
                 .put(CodegenConstants.GROUP_ID, GROUP_ID)
                 .put(CodegenConstants.SOURCE_FOLDER, SOURCE_FOLDER)
                 .put(CodegenConstants.ENUM_PROPERTY_NAMING, ENUM_PROPERTY_NAMING)
+                .put(KotlinClientCodegen.DATE_LIBRARY, DATE_LIBRARY)
                 .build();
     }