fix: preserve empty array body in stripEmptySlots

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>

Author: Copilot

packages/openapi-ts/src/plugins/@hey-api/client-core/__tests__/params.test.ts

@@ -344,6 +344,18 @@ describe('buildClientParams', () => {
       description: 'strip empty slots',
       params: {},
     },
+    {
+      args: [[]],
+      config: [
+        {
+          in: 'body',
+        },
+      ],
+      description: 'empty array body',
+      params: {
+        body: [],
+      },
+    },
   ];
 
   it.each(scenarios)('$description', async ({ args, config, params }) => {

packages/openapi-ts/src/plugins/@hey-api/client-core/bundle/params.ts

@@ -94,7 +94,7 @@ interface Params {
 
 const stripEmptySlots = (params: Params) => {
   for (const [slot, value] of Object.entries(params)) {
-    if (value && typeof value === 'object' && !Object.keys(value).length) {
+    if (value && typeof value === 'object' && !Array.isArray(value) && !Object.keys(value).length) {
       delete params[slot as Slot];
     }
   }