fix: avoid reporting unsaved empty image responses

src/sdk/image/index.ts

@@ -48,27 +48,28 @@ export class ImageSDK extends Client {
 
     if (options.out) {
       // Single-image, exact path
-      const count = (fmt === 'base64'
-        ? (response.data.image_base64 || []).length
-        : (response.data.image_urls || []).length);
+      const images = fmt === 'base64'
+        ? response.data.image_base64 || []
+        : response.data.image_urls || [];
 
-      if (count > 1) {
+      if (images.length > 1) {
         throw new SDKError(
           'Cannot use `out` with multiple images. Use `outDir` instead.',
           ExitCode.USAGE,
         );
       }
 
+      const image = images[0];
+      if (!image?.trim()) return saved;
+
       const destPath = resolve(options.out);
       const dir = dirname(destPath);
       if (!existsSync(dir)) mkdirSync(dir, { recursive: true });
 
       if (fmt === 'base64') {
-        const image = (response.data.image_base64 || [])[0];
-        if (image) writeFileSync(destPath, image, 'base64');
+        writeFileSync(destPath, image, 'base64');
       } else {
-        const imageUrl = (response.data.image_urls || [])[0];
-        if (imageUrl) await downloadFile(imageUrl, destPath, { quiet });
+        await downloadFile(image, destPath, { quiet });
       }
       saved.push(destPath);
     } else {

test/sdk/image-empty-save.test.ts

@@ -0,0 +1,65 @@
+import { describe, expect, it } from 'bun:test';
+import { existsSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { ImageSDK } from '../../src/sdk/image';
+import type { ImageResponse } from '../../src/types/api';
+import { withStubbedFetch } from '../helpers/fetch-stub';
+
+const sdk = new ImageSDK({ apiKey: 'test-key', region: 'global' });
+
+function response(format: 'url' | 'base64', images?: string[]): ImageResponse {
+  return {
+    base_resp: { status_code: 0, status_msg: 'ok' },
+    data: {
+      ...(format === 'url' ? { image_urls: images } : { image_base64: images }),
+      task_id: 'empty-images',
+      success_count: 0,
+      failed_count: 1,
+    },
+  };
+}
+
+describe('ImageSDK.save with no image data', () => {
+  for (const format of ['url', 'base64'] as const) {
+    for (const images of [undefined, [], [''], [' \n\t ']]) {
+      it(`does not report a saved path or create directories for ${format} ${JSON.stringify(images)}`, async () => {
+        const dir = mkdtempSync(join(tmpdir(), 'mmx-image-empty-'));
+        const out = join(dir, 'nested', 'image.jpg');
+        try {
+          expect(await sdk.save(response(format, images), { out, responseFormat: format })).toEqual([]);
+          expect(existsSync(join(dir, 'nested'))).toBe(false);
+        } finally {
+          rmSync(dir, { recursive: true, force: true });
+        }
+      });
+    }
+
+    it(`leaves an existing destination intact without reporting it as saved (${format})`, async () => {
+      const dir = mkdtempSync(join(tmpdir(), 'mmx-image-existing-'));
+      const out = join(dir, 'image.jpg');
+      try {
+        writeFileSync(out, 'existing image');
+        expect(await sdk.save(response(format, []), { out, responseFormat: format })).toEqual([]);
+        expect(readFileSync(out, 'utf8')).toBe('existing image');
+      } finally {
+        rmSync(dir, { recursive: true, force: true });
+      }
+    });
+  }
+
+  it('still downloads a valid single URL image to the requested nested path', async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'mmx-image-download-'));
+    const out = join(dir, 'nested', 'image.jpg');
+    const bytes = new Uint8Array([0xff, 0xd8, 0xff, 0xd9]);
+    try {
+      await withStubbedFetch(() => new Response(bytes), async (sent) => {
+        expect(await sdk.save(response('url', ['https://example.com/image']), { out })).toEqual([out]);
+        expect(sent.url).toBe('https://example.com/image');
+      });
+      expect(new Uint8Array(readFileSync(out))).toEqual(bytes);
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});