fix(storage): include metadata in uploadToSignedUrl request

The uploadToSignedUrl method accepted metadata in fileOptions but never
used it. This copies the metadata handling from uploadOrUpdate into
uploadToSignedUrl for all three body types (Blob, FormData, raw body).

Also forwards custom fileOptions.headers, matching uploadOrUpdate behavior.

Fixes supabase/storage#823

Author: MaxwellCalkin

packages/core/storage-js/src/packages/StorageFileApi.ts

@@ -252,23 +252,41 @@ export default class StorageFileApi extends BaseApiClient<StorageError> {
 
     return this.handleOperation(async () => {
       let body
-      const options = { upsert: DEFAULT_FILE_OPTIONS.upsert, ...fileOptions }
-      const headers: Record<string, string> = {
+      const options = { ...DEFAULT_FILE_OPTIONS, upsert: DEFAULT_FILE_OPTIONS.upsert, ...fileOptions }
+      let headers: Record<string, string> = {
         ...this.headers,
         ...{ 'x-upsert': String(options.upsert as boolean) },
       }
 
+      const metadata = options.metadata
+
       if (typeof Blob !== 'undefined' && fileBody instanceof Blob) {
         body = new FormData()
         body.append('cacheControl', options.cacheControl as string)
+        if (metadata) {
+          body.append('metadata', this.encodeMetadata(metadata))
+        }
         body.append('', fileBody)
       } else if (typeof FormData !== 'undefined' && fileBody instanceof FormData) {
         body = fileBody
-        body.append('cacheControl', options.cacheControl as string)
+        if (!body.has('cacheControl')) {
+          body.append('cacheControl', options.cacheControl as string)
+        }
+        if (metadata && !body.has('metadata')) {
+          body.append('metadata', this.encodeMetadata(metadata))
+        }
       } else {
         body = fileBody
         headers['cache-control'] = `max-age=${options.cacheControl}`
         headers['content-type'] = options.contentType as string
+
+        if (metadata) {
+          headers['x-metadata'] = this.toBase64(this.encodeMetadata(metadata))
+        }
+      }
+
+      if (fileOptions?.headers) {
+        headers = { ...headers, ...fileOptions.headers }
       }
 
       const data = await put(this.fetch, url.toString(), body as object, { headers })

packages/core/storage-js/test/storageFileApi.test.ts

@@ -920,6 +920,52 @@ describe('StorageFileApi Edge Cases', () => {
       expect(body).toBe(testFormData)
     })
 
+    test('uploadToSignedUrl with Blob includes metadata in FormData', async () => {
+      const testBlob = new Blob(['test content'], { type: 'text/plain' })
+      const metadata = { customKey: 'customValue', author: 'test' }
+
+      await storage
+        .from('test-bucket')
+        .uploadToSignedUrl('test-path', 'test-token', testBlob, { metadata })
+
+      expect(mockPut).toHaveBeenCalled()
+      const [, , body] = mockPut.mock.calls[0] as [null, null, FormData]
+      expect(body.constructor.name).toBe('FormData')
+      expect(body.get('metadata')).toBe(JSON.stringify(metadata))
+    })
+
+    test('uploadToSignedUrl with FormData includes metadata', async () => {
+      const testFormData = new FormData()
+      testFormData.append('file', 'test content')
+      const metadata = { customKey: 'customValue' }
+
+      await storage
+        .from('test-bucket')
+        .uploadToSignedUrl('test-path', 'test-token', testFormData, { metadata })
+
+      expect(mockPut).toHaveBeenCalled()
+      const [, , body] = mockPut.mock.calls[0] as [null, null, FormData]
+      expect(body).toBe(testFormData)
+      expect(body.get('metadata')).toBe(JSON.stringify(metadata))
+    })
+
+    test('uploadToSignedUrl with raw body includes metadata in headers', async () => {
+      const testBody = 'raw string content'
+      const metadata = { customKey: 'customValue' }
+
+      await storage
+        .from('test-bucket')
+        .uploadToSignedUrl('test-path', 'test-token', testBody, { metadata })
+
+      expect(mockPut).toHaveBeenCalled()
+      const [, , , { headers }] = mockPut.mock.calls[0]
+      const expectedBase64 =
+        typeof Buffer !== 'undefined'
+          ? Buffer.from(JSON.stringify(metadata)).toString('base64')
+          : btoa(JSON.stringify(metadata))
+      expect(headers['x-metadata']).toBe(expectedBase64)
+    })
+
     test('upload with metadata', async () => {
       const testBlob = new Blob(['test content'], { type: 'text/plain' })
       const metadata = { customKey: 'customValue', author: 'test' }