Return true unconditionally if mode is only_on_device

Author: erikeldridge

Diff for: packages/vertexai/src/methods/chrome-adapter.test.ts

@@ -61,19 +61,8 @@ describe('ChromeAdapter', () => {
         })
       ).to.be.false;
     });
-    it('returns false if AI API is undefined', async () => {
-      const adapter = new ChromeAdapter(undefined, 'prefer_on_device');
-      expect(
-        await adapter.isAvailable({
-          contents: []
-        })
-      ).to.be.false;
-    });
     it('returns false if LanguageModel API is undefined', async () => {
-      const adapter = new ChromeAdapter(
-        {} as LanguageModel,
-        'prefer_on_device'
-      );
+      const adapter = new ChromeAdapter(undefined, 'prefer_on_device');
       expect(
         await adapter.isAvailable({
           contents: []
@@ -82,7 +71,9 @@ describe('ChromeAdapter', () => {
     });
     it('returns false if request contents empty', async () => {
       const adapter = new ChromeAdapter(
-        {} as LanguageModel,
+        {
+          availability: async () => Availability.available
+        } as LanguageModel,
         'prefer_on_device'
       );
       expect(
@@ -93,7 +84,9 @@ describe('ChromeAdapter', () => {
     });
     it('returns false if request content has function role', async () => {
       const adapter = new ChromeAdapter(
-        {} as LanguageModel,
+        {
+          availability: async () => Availability.available
+        } as LanguageModel,
         'prefer_on_device'
       );
       expect(
@@ -107,51 +100,6 @@ describe('ChromeAdapter', () => {
         })
       ).to.be.false;
     });
-    it('returns false if request system instruction has function role', async () => {
-      const adapter = new ChromeAdapter(
-        {} as LanguageModel,
-        'prefer_on_device'
-      );
-      expect(
-        await adapter.isAvailable({
-          contents: [],
-          systemInstruction: {
-            role: 'function',
-            parts: []
-          }
-        })
-      ).to.be.false;
-    });
-    it('returns false if request system instruction has multiple parts', async () => {
-      const adapter = new ChromeAdapter(
-        {} as LanguageModel,
-        'prefer_on_device'
-      );
-      expect(
-        await adapter.isAvailable({
-          contents: [],
-          systemInstruction: {
-            role: 'function',
-            parts: [{ text: 'a' }, { text: 'b' }]
-          }
-        })
-      ).to.be.false;
-    });
-    it('returns false if request system instruction has non-text part', async () => {
-      const adapter = new ChromeAdapter(
-        {} as LanguageModel,
-        'prefer_on_device'
-      );
-      expect(
-        await adapter.isAvailable({
-          contents: [],
-          systemInstruction: {
-            role: 'function',
-            parts: [{ inlineData: { mimeType: 'a', data: 'b' } }]
-          }
-        })
-      ).to.be.false;
-    });
     it('returns true if model is readily available', async () => {
       const languageModelProvider = {
         availability: () => Promise.resolve(Availability.available)

Diff for: packages/vertexai/src/methods/chrome-adapter.ts

@@ -60,29 +60,23 @@ export class ChromeAdapter {
    * separation of concerns.</p>
    */
   async isAvailable(request: GenerateContentRequest): Promise<boolean> {
-    // Returns false if we should only use in-cloud inference.
     if (this.mode === 'only_in_cloud') {
       return false;
     }
-    // Returns false if the on-device inference API is undefined.;
-    if (!this.languageModelProvider) {
-      return false;
+    console.log(this.languageModelProvider);
+    const availability = await this.languageModelProvider?.availability();
+    if (availability === Availability.downloadable) {
+      // Triggers async model download.
+      this.download();
     }
-    // Returns false if the request can't be run on-device.
-    if (!ChromeAdapter.isOnDeviceRequest(request)) {
-      return false;
-    }
-    const availability = await this.languageModelProvider.availability();
-    switch (availability) {
-      case Availability.available:
-        // Returns true only if a model is immediately available.
-        return true;
-      case Availability.downloadable:
-        // Triggers async download if model is downloadable.
-        this.download();
-      default:
-        return false;
+    if (this.mode === 'only_on_device') {
+      return true;
     }
+    // Applies prefer_on_device logic.
+    return (
+      availability === Availability.available &&
+      ChromeAdapter.isOnDeviceRequest(request)
+    );
   }
 
   /**