fix(client-axios): ensures falsy request body can be serialized

ensures request is sent with valid serialized or unserialized data

resolves: #2599, related: #2553

Author: Fransis Young

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

@@ -1,5 +1,6 @@
+import type { AxiosInstance } from 'axios';
 import axios from 'axios';
-import { describe, expect, it } from 'vitest';
+import { describe, expect, it, vi } from 'vitest';
 
 import { createClient } from '../bundle/client';
 
@@ -83,3 +84,87 @@ describe('AxiosInstance', () => {
     );
   });
 });
+
+describe('unserialized request body handling', () => {
+  const client = createClient({ baseURL: 'https://example.com' });
+
+  const scenarios = [
+    { body: 0 },
+    { body: false },
+    { body: 'test string' },
+    { body: '' },
+  ];
+
+  it.each(scenarios)(
+    'handles plain text body with $body value',
+    async ({ body }) => {
+      const mockAxios = vi.fn();
+
+      await client.post({
+        axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
+        body,
+        bodySerializer: null,
+        headers: {
+          'Content-Type': 'text/plain',
+        },
+        url: '/test',
+      });
+
+      expect(mockAxios).toHaveBeenCalledWith(
+        expect.objectContaining({
+          data: body,
+        }),
+      );
+    },
+  );
+});
+
+describe('serialized request body handling', () => {
+  const client = createClient({ baseURL: 'https://example.com' });
+
+  const scenarios = [
+    {
+      body: '',
+      expectBodyValue: false,
+      serializedBody: '',
+    },
+    {
+      body: 0,
+      expectBodyValue: true,
+      serializedBody: 0,
+    },
+    {
+      body: false,
+      expectBodyValue: true,
+      serializedBody: false,
+    },
+    {
+      body: {},
+      expectBodyValue: true,
+      serializedBody: '{"key":"value"}',
+    },
+  ];
+
+  it.each(scenarios)(
+    'handles $serializedBody serializedBody value',
+    async ({ body, expectBodyValue, serializedBody }) => {
+      const mockAxios = vi.fn();
+
+      await client.post({
+        axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
+        body,
+        bodySerializer: () => serializedBody,
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        url: '/test',
+      });
+
+      expect(mockAxios).toHaveBeenCalledWith(
+        expect.objectContaining({
+          data: expectBodyValue ? serializedBody : null,
+        }),
+      );
+    },
+  );
+});

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

@@ -57,7 +57,7 @@ export const createClient = (config: Config = {}): Client => {
       await opts.requestValidator(opts);
     }
 
-    if (opts.body && opts.bodySerializer) {
+    if (opts.body !== undefined && opts.bodySerializer) {
       opts.body = opts.bodySerializer(opts.body);
     }
 
@@ -78,7 +78,7 @@ export const createClient = (config: Config = {}): Client => {
       const response = await _axios({
         ...optsWithoutAuth,
         baseURL: opts.baseURL as string,
-        data: opts.body,
+        data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
         params: opts.paramsSerializer ? opts.query : undefined,
@@ -112,6 +112,23 @@ export const createClient = (config: Config = {}): Client => {
     }
   };
 
+  function getValidRequestBody(options: RequestOptions) {
+    const hasBody = options.body !== undefined;
+    const isSerializedBody = hasBody && options.bodySerializer;
+
+    if (isSerializedBody) {
+      return options.body !== '' ? options.body : null;
+    }
+
+    // plain/text body
+    if (hasBody) {
+      return options.body;
+    }
+
+    // no body was provided
+    return undefined;
+  }
+
   const makeMethodFn =
     (method: Uppercase<HttpMethod>) => (options: RequestOptions) =>
       request({ ...options, method });