feat: add 3.1 oneOf+const structure as enum

src/openApi/v3/interfaces/JsonCustomVocabulary.d.ts

@@ -0,0 +1,5 @@
+// https://json-schema.org/draft/2020-12/json-schema-core.html#name-non-json-instances
+
+export interface JsonCustomVocabulary {
+    const?: string | number;
+}

src/openApi/v3/interfaces/OpenApiSchema.d.ts

@@ -1,5 +1,6 @@
 import type { Dictionary } from '../../../utils/types';
 import type { WithEnumExtension } from './Extensions/WithEnumExtension';
+import type { JsonCustomVocabulary } from './JsonCustomVocabulary';
 import type { OpenApiDiscriminator } from './OpenApiDiscriminator';
 import type { OpenApiExternalDocs } from './OpenApiExternalDocs';
 import type { OpenApiReference } from './OpenApiReference';
@@ -8,7 +9,7 @@ import type { OpenApiXml } from './OpenApiXml';
 /**
  * https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#schemaObject
  */
-export interface OpenApiSchema extends OpenApiReference, WithEnumExtension {
+export interface OpenApiSchema extends OpenApiReference, WithEnumExtension, JsonCustomVocabulary {
     title?: string;
     multipleOf?: number;
     maximum?: number;

src/openApi/v3/parser/getModel.ts

@@ -1,3 +1,4 @@
+import { Enum } from '../../../client/interfaces/Enum';
 import type { Model } from '../../../client/interfaces/Model';
 import { getPattern } from '../../../utils/getPattern';
 import type { OpenApi } from '../interfaces/OpenApi';
@@ -8,6 +9,7 @@ import { getModelComposition } from './getModelComposition';
 import { getModelDefault } from './getModelDefault';
 import { getModelProperties } from './getModelProperties';
 import { getType } from './getType';
+import { getOneOfEnum } from "./getOneOfEnum";
 
 export const getModel = (
     openApi: OpenApi,
@@ -68,6 +70,7 @@ export const getModel = (
             model.base = 'string';
             model.enum.push(...extendedEnumerators);
             model.default = getModelDefault(definition, model);
+
             return model;
         }
     }
@@ -118,7 +121,22 @@ export const getModel = (
         }
     }
 
-    if (definition.oneOf?.length) {
+    if (
+        definition.oneOf?.length &&
+        (definition.type === 'integer' || definition.type === 'string') &&
+        (typeof definition.oneOf?.at(0)?.const === 'number' || typeof definition.oneOf?.at(0)?.const === 'string')
+    ) {
+        const enumerator: Enum[] = getOneOfEnum(definition.oneOf);
+        if (enumerator.length) {
+            model.export = 'enum';
+            model.type = 'string';
+            model.base = 'string';
+            model.enum.push(...enumerator);
+            model.default = getModelDefault(definition, model);
+
+            return model;
+        }
+    } else if (definition.oneOf?.length) {
         const composition = getModelComposition(openApi, definition, definition.oneOf, 'one-of', getModel);
         model.export = composition.type;
         model.imports.push(...composition.imports);

src/openApi/v3/parser/getOneOfEnum.ts

@@ -0,0 +1,22 @@
+import type { Enum } from '../../../client/interfaces/Enum';
+import { OpenApiSchema } from '../interfaces/OpenApiSchema';
+
+export const getOneOfEnum = (oneOf: OpenApiSchema[]): Enum[] =>
+    oneOf.reduce((enums, item) => {
+        if (typeof item.const === 'number') {
+            enums.push({
+                value: String(item.const),
+                name: `${item.title}` || `'_${item.const}'`,
+                type: 'number',
+                description: item.description || item.title || null,
+            });
+        } else {
+            enums.push({
+                value: `'${item.const}'`,
+                name: `${item.title}` || `'${item.const}'`,
+                type: 'string',
+                description: item.description || item.title || null,
+            });
+        }
+        return enums;
+    }, [] as Enum[]);

test/__snapshots__/index.spec.ts.snap

@@ -3639,6 +3639,8 @@ export type { DictionaryWithProperties } from './models/DictionaryWithProperties
 export type { DictionaryWithReference } from './models/DictionaryWithReference';
 export type { DictionaryWithString } from './models/DictionaryWithString';
 export type { EnumFromDescription } from './models/EnumFromDescription';
+export { EnumViaOneOfNumeric } from './models/EnumViaOneOfNumeric';
+export { EnumViaOneOfString } from './models/EnumViaOneOfString';
 export { EnumWithExtensions } from './models/EnumWithExtensions';
 export { EnumWithNumbers } from './models/EnumWithNumbers';
 export { EnumWithStrings } from './models/EnumWithStrings';
@@ -3704,6 +3706,8 @@ export { $DictionaryWithProperties } from './schemas/$DictionaryWithProperties';
 export { $DictionaryWithReference } from './schemas/$DictionaryWithReference';
 export { $DictionaryWithString } from './schemas/$DictionaryWithString';
 export { $EnumFromDescription } from './schemas/$EnumFromDescription';
+export { $EnumViaOneOfNumeric } from './schemas/$EnumViaOneOfNumeric';
+export { $EnumViaOneOfString } from './schemas/$EnumViaOneOfString';
 export { $EnumWithExtensions } from './schemas/$EnumWithExtensions';
 export { $EnumWithNumbers } from './schemas/$EnumWithNumbers';
 export { $EnumWithStrings } from './schemas/$EnumWithStrings';
@@ -4247,6 +4251,82 @@ export type EnumFromDescription = number;
 "
 `;
 
+exports[`v3 should generate: ./test/generated/v3/models/EnumLike.ts 1`] = `
+"/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+
+/**
+ * OpenApi 3.1 style numeric enum
+ */
+export enum EnumLike {
+    /**
+    * Success
+    * /
+    SUCCESS = 0,
+    /**
+     * Warning
+     */
+    'WARNING' = 1,
+    /**
+     * Error
+     */
+    'ERROR' = 3,
+};
+
+"
+`;
+
+exports[`v3 should generate: ./test/generated/v3/models/EnumViaOneOfNumeric.ts 1`] = `
+"/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+
+/**
+ * OpenApi 3.1 style numeric enum
+ */
+export enum EnumViaOneOfNumeric {
+    /**
+     * Success
+     */
+    SUCCESS = 0,
+    /**
+     * Warning
+     */
+    WARNING = 1,
+    /**
+     * Error
+     */
+    ERROR = 3,
+}
+"
+`;
+
+exports[`v3 should generate: ./test/generated/v3/models/EnumViaOneOfString.ts 1`] = `
+"/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+
+/**
+ * OpenApi 3.1 style numeric enum
+ */
+export enum EnumViaOneOfString {
+    /**
+     * Success
+     */
+    SUCCESS = 'SUCCESS',
+    /**
+     * Warning
+     */
+    WARNING = 'SUCCESS',
+    /**
+     * Error
+     */
+    ERROR = 'SUCCESS',
+}
+"
+`;
+
 exports[`v3 should generate: ./test/generated/v3/models/EnumWithExtensions.ts 1`] = `
 "/* istanbul ignore file */
 /* tslint:disable */
@@ -4281,6 +4361,7 @@ exports[`v3 should generate: ./test/generated/v3/models/EnumWithNumbers.ts 1`] =
  * This is a simple enum with numbers
  */
 export enum EnumWithNumbers {
+    '_0' = 0,
     '_1' = 1,
     '_2' = 2,
     '_3' = 3,
@@ -5447,6 +5528,26 @@ export const $EnumFromDescription = {
 "
 `;
 
+exports[`v3 should generate: ./test/generated/v3/schemas/$EnumViaOneOfNumeric.ts 1`] = `
+"/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+export const $EnumViaOneOfNumeric = {
+    type: 'Enum',
+} as const;
+"
+`;
+
+exports[`v3 should generate: ./test/generated/v3/schemas/$EnumViaOneOfString.ts 1`] = `
+"/* istanbul ignore file */
+/* tslint:disable */
+/* eslint-disable */
+export const $EnumViaOneOfString = {
+    type: 'Enum',
+} as const;
+"
+`;
+
 exports[`v3 should generate: ./test/generated/v3/schemas/$EnumWithExtensions.ts 1`] = `
 "/* istanbul ignore file */
 /* tslint:disable */

test/spec/v3.json

@@ -1567,6 +1567,7 @@
             "EnumWithNumbers": {
                 "description": "This is a simple enum with numbers",
                 "enum": [
+                    0,
                     1,
                     2,
                     3,
@@ -1606,6 +1607,48 @@
                     "Used when the status of something has an error"
                 ]
             },
+            "EnumViaOneOfNumeric": {
+                "description": "OpenApi 3.1 style numeric enum",
+                "type": "integer",
+                "oneOf": [
+                    {
+                        "const": 0,
+                        "title": "SUCCESS",
+                        "description": "Success"
+                    },
+                    {
+                        "const": 1,
+                        "title": "WARNING",
+                        "description": "Warning"
+                    },
+                    {
+                        "const": 3,
+                        "title": "ERROR",
+                        "description": "Error"
+                    }
+                ]
+            },
+            "EnumViaOneOfString": {
+                "description": "OpenApi 3.1 style titled enum",
+                "type": "string",
+                "oneOf": [
+                    {
+                        "const": "SUCCESS",
+                        "title": "SUCCESS",
+                        "description": "Success"
+                    },
+                    {
+                        "const": "SUCCESS",
+                        "title": "WARNING",
+                        "description": "Warning"
+                    },
+                    {
+                        "const": "SUCCESS",
+                        "title": "ERROR",
+                        "description": "Error"
+                    }
+                ]
+            },
             "ArrayWithNumbers": {
                 "description": "This is a simple array with numbers",
                 "type": "array",