[Codegen] Convert "any type" to oneOf model

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

@@ -74,7 +74,26 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public Set<String> allMandatory = new TreeSet<String>(); // with parent's required properties
 
     public Set<String> imports = new TreeSet<String>();
-    public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum, isNullable, hasRequired, hasOptional, isArrayModel, hasChildren, isMapModel, isDeprecated;
+    public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum;
+    /**
+     * Indicates the OAS schema specifies "nullable: true".
+     */
+    public boolean isNullable;
+    /**
+     * Indicates the type has at least one required property.
+     */
+    public boolean hasRequired;
+    /**
+     * Indicates the type has at least one optional property.
+     */
+    public boolean hasOptional;
+    public boolean isArrayModel;
+    public boolean hasChildren;
+    public boolean isMapModel;
+    /**
+     * Indicates the OAS schema specifies "deprecated: true".
+     */
+    public boolean isDeprecated;
     public boolean hasOnlyReadOnly = true; // true if all properties are read-only
     public ExternalDocumentation externalDocumentation;
 

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

@@ -1774,6 +1774,10 @@ public String toDefaultValueWithParam(String name, Schema schema) {
      **/
     @SuppressWarnings("static-method")
     public String getSchemaType(Schema schema) {
+        if (schema == null) {
+            // This is indicative of a bug in codegen.
+            throw new RuntimeException("getSchemaType schema argument is null");
+        }
         if (schema instanceof ComposedSchema) { // composed schema
             ComposedSchema cs = (ComposedSchema) schema;
             // Get the interfaces, i.e. the set of elements under 'allOf', 'anyOf' or 'oneOf'.
@@ -1886,7 +1890,9 @@ public String toOneOfName(List<String> names, ComposedSchema composedSchema) {
      */
     private String getSingleSchemaType(Schema schema) {
         Schema unaliasSchema = ModelUtils.unaliasSchema(this.openAPI, schema, importMapping);
-
+        if (unaliasSchema == null) {
+            throw new RuntimeException("Schema '" + schema.getName() + "' is invalid");
+        }
         if (StringUtils.isNotBlank(unaliasSchema.get$ref())) { // reference to another definition/schema
             // get the schema/model name from $ref
             String schemaName = ModelUtils.getSimpleRef(unaliasSchema.get$ref());
@@ -2010,15 +2016,15 @@ public String getTypeDeclaration(String name) {
     }
 
     /**
-     * Output the type declaration of the property
+     * Output the language-specific type declaration of the property.
      *
      * @param schema property schema
      * @return a string presentation of the property type
      */
     public String getTypeDeclaration(Schema schema) {
         if (schema == null) {
-            LOGGER.warn("Null schema found. Default type to `NULL_SCHMEA_ERR`");
-            return "NULL_SCHMEA_ERR";
+            LOGGER.warn("Null schema found. Default type to `NULL_SCHEMA_ERR`");
+            return "NULL_SCHEMA_ERR";
         }
 
         String oasType = getSchemaType(schema);
@@ -2100,6 +2106,70 @@ public String toModelName(final String name) {
         return camelize(modelNamePrefix + "_" + name + "_" + modelNameSuffix);
     }
 
+    /**
+     * Returns a composed model that encapsulates the JSON schema "any type".
+     * Its value can be any of null, integer, boolean, number, string, array or map.
+     */
+    protected Schema getAnyTypeSchema(String name, Schema schema) {
+        if (!ModelUtils.isAnyTypeSchema(schema)) {
+            throw new RuntimeException("Schema '" + name + "' is not 'any type'");
+        }
+        ComposedSchema cs = (ComposedSchema) new ComposedSchema()
+            .addAnyOfItem(new ObjectSchema().type("null"))
+            .addAnyOfItem(new BooleanSchema())
+            .addAnyOfItem(new StringSchema()
+                    .minLength(schema.getMinLength())
+                    .maxLength(schema.getMaxLength())
+                    .pattern(schema.getPattern())
+                )
+            .addAnyOfItem(new IntegerSchema()
+                    .minimum(schema.getMinimum())
+                    .maximum(schema.getMaximum())
+                    .exclusiveMinimum(schema.getExclusiveMinimum())
+                    .exclusiveMaximum(schema.getExclusiveMaximum())
+                    .multipleOf(schema.getMultipleOf())
+                )
+            .addAnyOfItem(new NumberSchema()
+                    .minimum(schema.getMinimum())
+                    .maximum(schema.getMaximum())
+                    .exclusiveMinimum(schema.getExclusiveMinimum())
+                    .exclusiveMaximum(schema.getExclusiveMaximum())
+                    .multipleOf(schema.getMultipleOf())
+                )
+            .name(name);
+
+        // The map keys must be strings and the values can be anything.
+        cs.addAnyOfItem(new MapSchema()
+            .additionalProperties(true)
+            .minProperties(schema.getMinProperties())
+            .maxProperties(schema.getMaxProperties())
+            .required(schema.getRequired())
+        );
+        // The array items can be anything.
+        cs.addAnyOfItem(new ArraySchema()
+                .minItems(schema.getMinItems())
+                .maxItems(schema.getMaxItems())
+                .uniqueItems(schema.getUniqueItems())
+            );
+        if (schema != null) {
+            cs.setTitle(schema.getTitle());
+            cs.setDescription(schema.getDescription());
+        }
+        return cs;
+    }
+
+    // Returns a model that encapsulates the JSON schema "any type". Its value
+    // can be any of null, integer, boolean, number, string, array or map.
+    // "Any type" is a schema that does not have the "type" attribute
+    // specified in the OpenAPI schema. That means the value can be any valid
+    // payload, i.e. the null value, boolean, string, integer, number,
+    // array or map.
+    // Numerical payloads may match more than one type, for example "2" may
+    // match integer and number. Hence the use of 'anyOf'.
+    public CodegenModel getAnyTypeModel(String name, Schema schema) {
+        return fromModel(name, getAnyTypeSchema(name, schema));
+    }
+
     /**
      * Convert OAS Model object to Codegen Model object
      *
@@ -2121,6 +2191,11 @@ public CodegenModel fromModel(String name, Schema schema) {
             return null;
         }
 
+        if (ModelUtils.isAnyTypeSchema(schema)) {
+            // "Any type" means the payload can be any type, e.g. integer, number, object, array...
+            return getAnyTypeModel(name, schema);
+        }
+
         CodegenModel m = CodegenModelFactory.newInstance(CodegenModelType.MODEL);
 
         if (reservedWords.contains(name)) {
@@ -2155,7 +2230,6 @@ public CodegenModel fromModel(String name, Schema schema) {
             m.xmlNamespace = schema.getXml().getNamespace();
             m.xmlName = schema.getXml().getName();
         }
-
         if (ModelUtils.isArraySchema(schema)) {
             m.isArrayModel = true;
             m.arrayModelType = fromProperty(name, schema).complexType;
@@ -2801,7 +2875,7 @@ public String getterAndSetterCapitalize(String name) {
      * Convert OAS Property object to Codegen Property object
      *
      * @param name name of the property
-     * @param p    OAS property object
+     * @param p    OAS property schema
      * @return Codegen Property object
      */
     public CodegenProperty fromProperty(String name, Schema p) {
@@ -2814,6 +2888,9 @@ public CodegenProperty fromProperty(String name, Schema p) {
         // unalias schema
         p = ModelUtils.unaliasSchema(this.openAPI, p, importMapping);
 
+        if (ModelUtils.isAnyTypeSchema(p)) {
+            p = getAnyTypeSchema(name, p);
+        }
         CodegenProperty property = CodegenModelFactory.newInstance(CodegenModelType.PROPERTY);
 
         ModelUtils.syncValidationProperties(p, property);

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

@@ -327,10 +327,23 @@ public String getTypeDeclaration(Schema p) {
         if (ModelUtils.isArraySchema(p)) {
             ArraySchema ap = (ArraySchema) p;
             Schema inner = ap.getItems();
-            return "[]" + getTypeDeclaration(ModelUtils.unaliasSchema(this.openAPI, inner));
+            // Per JSON schema specification, the "items" attribute in an Array schema
+            // is optional. When "items" is not specified, the elements of the array
+            // may be anything at all.
+            if (inner != null) {
+                inner = ModelUtils.unaliasSchema(this.openAPI, inner);
+            }
+            String typDecl;
+            if (inner != null) {
+                typDecl = getTypeDeclaration(inner);
+            } else {
+                typDecl = "interface{}";
+            }
+            return "[]" + typDecl;
         } else if (ModelUtils.isMapSchema(p)) {
             Schema inner = ModelUtils.getAdditionalProperties(p);
-            return getSchemaType(p) + "[string]" + getTypeDeclaration(ModelUtils.unaliasSchema(this.openAPI, inner));
+            inner = ModelUtils.unaliasSchema(this.openAPI, inner);
+            return getSchemaType(p) + "[string]" + getTypeDeclaration(inner);
         }
         //return super.getTypeDeclaration(p);
 

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

@@ -910,7 +910,14 @@ public String getTypeString(Schema p, String prefix, String suffix) {
         } else if (ModelUtils.isArraySchema(p)) {
             ArraySchema ap = (ArraySchema) p;
             Schema inner = ap.getItems();
-            return prefix + "[" + getTypeString(inner, "", "") + "]" + fullSuffix;
+            if (inner == null) {
+                // Per JSON schema specification, the array "items" attribute is optional.
+                // When "items" is not specified, the elements of the array
+                // may be anything at all.
+                return prefix + "[bool, date, datetime, dict, float, int, list, str, none_type]" + fullSuffix;
+            } else {
+                return prefix + "[" + getTypeString(inner, "", "") + "]" + fullSuffix;
+            }
         }
         if (ModelUtils.isFileSchema(p)) {
             return prefix + "file_type" + fullSuffix;

modules/openapi-generator/src/test/java/org/openapitools/codegen/dart/DartModelTest.java

@@ -287,7 +287,7 @@ public static Object[][] primeNumbers() {
     @Test(dataProvider = "modelNames", description = "avoid inner class")
     public void modelNameTest(String name, String expectedName) {
         OpenAPI openAPI = TestUtils.createOpenAPI();
-        final Schema model = new Schema();
+        final Schema model = new ObjectSchema();
         final DefaultCodegen codegen = new DartClientCodegen();
         codegen.setOpenAPI(openAPI);
         final CodegenModel cm = codegen.fromModel(name, model);

modules/openapi-generator/src/test/java/org/openapitools/codegen/dartdio/DartDioModelTest.java

@@ -25,6 +25,7 @@
 import io.swagger.v3.oas.models.media.IntegerSchema;
 import io.swagger.v3.oas.models.media.MapSchema;
 import io.swagger.v3.oas.models.media.Schema;
+import io.swagger.v3.oas.models.media.ObjectSchema;
 import io.swagger.v3.oas.models.media.StringSchema;
 import org.openapitools.codegen.ClientOptInput;
 import org.openapitools.codegen.CodegenConstants;
@@ -375,7 +376,7 @@ public static Object[][] primeNumbers() {
     @Test(dataProvider = "modelNames", description = "avoid inner class")
     public void modelNameTest(String name, String expectedName) {
         OpenAPI openAPI = TestUtils.createOpenAPI();
-        final Schema model = new Schema();
+        final Schema model = new ObjectSchema();
         final DefaultCodegen codegen = new DartDioClientCodegen();
         codegen.setOpenAPI(openAPI);
         final CodegenModel cm = codegen.fromModel(name, model);

modules/openapi-generator/src/test/java/org/openapitools/codegen/go/GoModelTest.java

@@ -294,7 +294,7 @@ public static Object[][] primeNumbers() {
 
     @Test(dataProvider = "modelNames", description = "avoid inner class")
     public void modelNameTest(String name, String expectedName) {
-        final Schema model = new Schema();
+        final Schema model = new ObjectSchema();
         final DefaultCodegen codegen = new GoClientCodegen();
         OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema(name, model);
         codegen.setOpenAPI(openAPI);

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelTest.java

@@ -279,6 +279,21 @@ public void complexPropertiesTest() {
         Assert.assertFalse(property.isContainer);
     }
 
+    @Test(description = "test 'any type' schema")
+    public void anyTypeSchemaTest() {
+        // Create a schema without any constraint.
+        final Schema schema = new Schema()
+                .description("a sample model");
+        final DefaultCodegen codegen = new JavaClientCodegen();
+        OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema("sample", schema);
+        codegen.setOpenAPI(openAPI);
+        final CodegenModel cm = codegen.fromModel("sample", schema);
+        // 
+        Assert.assertEquals(cm.name, "sample");
+        Assert.assertEquals(cm.classname, "Sample");
+        Assert.assertEquals(cm.description, "a sample model");
+    }
+
     @Test(description = "convert a model with complex list property")
     public void complexListPropertyTest() {
         final Schema schema = new Schema()
@@ -713,7 +728,7 @@ public static Object[][] primeNumbers() {
 
     @Test(dataProvider = "modelNames", description = "avoid inner class")
     public void modelNameTest(String name, String expectedName) {
-        final Schema schema = new Schema();
+        final Schema schema = new ObjectSchema();
         final DefaultCodegen codegen = new JavaClientCodegen();
         OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema(name, schema);
         codegen.setOpenAPI(openAPI);

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinReservedWordsTest.java

@@ -2,6 +2,7 @@
 
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
+import io.swagger.v3.oas.models.media.ObjectSchema;
 import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.parameters.Parameter;
 import org.openapitools.codegen.*;
@@ -55,7 +56,7 @@ static Object[][] reservedWords() {
     @Test(dataProvider = "reservedWords")
     public void testReservedWordsAsModels(String reservedWord) {
         final DefaultCodegen codegen = new KotlinClientCodegen();
-        final Schema schema = new Schema();
+        final Schema schema = new ObjectSchema();
         final String escaped = "`" + reservedWord + "`";
         final String titleCased = StringUtils.camelize(reservedWord, false);
 

modules/openapi-generator/src/test/java/org/openapitools/codegen/php/PhpModelTest.java

@@ -290,7 +290,7 @@ public static Object[][] primeNumbers() {
 
     @Test(dataProvider = "modelNames", description = "avoid inner class")
     public void modelNameTest(String name, String expectedName) {
-        final Schema model = new Schema();
+        final Schema model = new ObjectSchema();
         final DefaultCodegen codegen = new PhpClientCodegen();
         OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema(name, model);
         codegen.setOpenAPI(openAPI);

modules/openapi-generator/src/test/java/org/openapitools/codegen/scalaakka/ScalaAkkaClientCodegenTest.java

@@ -398,7 +398,7 @@ public void codeGenerationJava8Test() throws Exception {
 
     @Test(description = "strip model name")
     public void stripModelNameTest() throws Exception {
-        final Schema model = new Schema()
+        final Schema model = new ObjectSchema()
                 .description("a map model");
         final DefaultCodegen codegen = new ScalaAkkaClientCodegen();
         OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema("sample", model);