fix: address CodeRabbit review findings

- fal image/video: spread modelOptions after derived media fields so
  explicit user overrides win (matches documented intent)
- openai video: validate effective size (size ?? modelOptions.size)
- generate-fal-image-field-map: run arity check for default-selected
  fields too
- ts-react-media example: correct reference-image support comment
  (Gemini multimodal models, not NanoBanana)
- e2e VideoGenUI: reject on malformed data URL instead of resolving ''

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: tombeckenham

examples/ts-react-media/src/components/ImageGenerator.tsx

@@ -197,7 +197,8 @@ export default function ImageGenerator({
               Reference Images
             </label>
             <span className="text-xs text-gray-500">
-              Supported by Gemini native (NanoBanana) models only
+              Supported by Gemini multimodal models only
+              (gemini-3.1-flash-image-preview, gemini-3-pro-image-preview)
             </span>
           </div>
           <div className="flex flex-wrap gap-2">

packages/ai-fal/src/adapters/image.ts

@@ -102,14 +102,15 @@ export class FalImageAdapter<TModel extends FalModel> extends BaseImageAdapter<
     resolved: ResolvedMediaPrompt,
   ): FalModelInput<TModel> {
     const sizeParams = mapSizeToFalFormat(options.size)
-    // Order matters: modelOptions first (so user overrides win for
-    // mask_url / control_image_url / reference_image_urls), then size,
-    // then derived image-input fields, then prompt / num_images.
+    // Order matters: size and derived image-input fields first, then
+    // modelOptions (so explicit user overrides win for mask_url /
+    // control_image_url / reference_image_urls), then the call-controlled
+    // prompt / num_images, which always take precedence.
     const inputFields = mapImageInputsToFalFields(this.model, resolved.images)
     const input = {
-      ...options.modelOptions,
       ...sizeParams,
       ...inputFields,
+      ...options.modelOptions,
       // Media-only prompts (e.g. upscalers, background removal) omit the
       // prompt field entirely rather than sending an empty string.
       ...(resolved.text ? { prompt: resolved.text } : {}),

packages/ai-fal/src/adapters/video.ts

@@ -162,11 +162,13 @@ export class FalVideoAdapter<TModel extends FalModel> extends BaseVideoAdapter<
       const audioFields = mapAudioInputsToFalFields(resolved.audios)
 
       const input = {
-        ...modelOptions,
         ...sizeParams,
         ...inputImageFields,
         ...videoFields,
         ...audioFields,
+        // modelOptions applied after derived media fields so explicit user
+        // overrides (video_url, reference_video_urls, audio_url, ...) win.
+        ...modelOptions,
         // Media-only prompts omit the prompt field rather than sending an
         // empty string (e.g. pure image-to-video endpoints).
         ...(resolved.text ? { prompt: resolved.text } : {}),

packages/ai-openai/src/adapters/video.ts

@@ -92,7 +92,8 @@ export class OpenAIVideoAdapter<
   ): Promise<VideoJobResult> {
     const { model, size, duration, modelOptions } = options
 
-    validateVideoSize(model, size)
+    const resolvedSize = size ?? modelOptions?.size
+    validateVideoSize(model, resolvedSize)
     const seconds = duration ?? modelOptions?.seconds
     validateVideoSeconds(model, seconds)
 
@@ -129,10 +130,8 @@ export class OpenAIVideoAdapter<
     }
     // `VideoCreateParams.size` is `size?: VideoSize` (no `| undefined`), so we
     // narrow before assignment instead of casting from a `T | undefined` source.
-    if (size) {
-      request.size = size
-    } else if (modelOptions?.size) {
-      request.size = modelOptions.size
+    if (resolvedSize) {
+      request.size = resolvedSize
     }
     if (seconds !== undefined) {
       // `toApiSeconds` returns `OpenAIVideoSeconds | undefined`; we already

scripts/generate-fal-image-field-map.ts

@@ -221,10 +221,12 @@ function computeOverrides(
     for (const role of ROLE_ORDER) {
       if (VIDEO_ONLY_ROLES.has(role) && !producesVideo) continue
       const chosen = CANDIDATES[role].find((candidate) => fields.has(candidate))
-      if (!chosen || chosen === DEFAULTS[role]) continue
+      if (!chosen) continue
 
       // Arity sanity check: the runtime mapper decides array-wrapping from
-      // the static LIST_FIELDS set, so the actual type must agree.
+      // the static LIST_FIELDS set, so the actual type must agree. Run this
+      // for default-selected fields too, otherwise a default field's type
+      // could drift silently.
       const actualIsList = isList.get(chosen) ?? false
       const assumedIsList = LIST_FIELDS.has(chosen)
       if (actualIsList !== assumedIsList) {
@@ -235,6 +237,7 @@ function computeOverrides(
             `and LIST_FIELDS in image-inputs.ts.`,
         )
       }
+      if (chosen === DEFAULTS[role]) continue
       entry[role] = chosen
     }
     if (Object.keys(entry).length > 0) overrides.set(endpointId, entry)

testing/e2e/src/components/VideoGenUI.tsx

@@ -27,7 +27,12 @@ function fileToBase64(file: File): Promise<string> {
         reject(new Error('Unexpected FileReader result'))
         return
       }
-      resolve(result.split(',')[1] ?? '')
+      const base64 = result.split(',')[1]
+      if (!base64) {
+        reject(new Error(`Unexpected data URL format: ${result.slice(0, 32)}…`))
+        return
+      }
+      resolve(base64)
     }
     reader.onerror = () => reject(new Error('Failed to read file'))
     reader.readAsDataURL(file)