feat: override openapi if exists json

package.json

@@ -36,6 +36,7 @@
   },
   "devDependencies": {
     "@types/minimist": "^1.2.5",
+    "@types/node": "^22.3.0",
     "eslint": "^9.9.0",
     "eslint-config-flat-gitignore": "^0.1.8",
     "eslint-config-prettier": "^9.1.0",

samples/openapi.json

@@ -1,8 +1,8 @@
 {
   "openapi": "3.1.0",
   "info": {
-    "title": "openapi api",
-    "version": "v0.0"
+    "title": "title test api",
+    "version": "v1.1"
   },
   "paths": {
     "/api/stream/v1/stories/{storyId}": {

src/index.ts

@@ -1,7 +1,7 @@
 import type { AspidaMethodParams } from 'aspida';
 import type { DirentTree } from 'aspida/dist/cjs/getDirentTree';
 import { getDirentTree } from 'aspida/dist/cjs/getDirentTree';
-import { unlinkSync, writeFileSync } from 'fs';
+import { existsSync, readFileSync, unlinkSync, writeFileSync } from 'fs';
 import type { OpenAPIV3_1 } from 'openapi-types';
 import { join } from 'path';
 import * as TJS from 'typescript-json-schema';
@@ -42,13 +42,18 @@ type AllMethods = [${paths.map((_, i) => `Methods${i}`).join(', ')}]`;
 
     const program = TJS.getProgramFromFiles([typeFilePath], compilerOptions);
     const schema = TJS.generateSchema(program, 'AllMethods', { required: true });
+    const existingDoc: OpenAPIV3_1.Document | undefined = existsSync(config.output)
+      ? JSON.parse(readFileSync(config.output, 'utf8'))
+      : undefined;
+
     const doc: OpenAPIV3_1.Document = {
       openapi: '3.1.0',
       info: {
         title: `${config.output.split('/').at(-1)?.replace('.json', '')} api`,
         version: 'v0.0',
       },
       servers: config.baseURL ? [{ url: config.baseURL }] : undefined,
+      ...existingDoc,
       paths: {},
       components: { schemas: schema?.definitions as any },
     };