Add backwards compatibility tests

Author: dlarocque

packages/vertexai/src/backwards-compatbility.test.ts

@@ -0,0 +1,58 @@
+import { expect } from "chai";
+import { GenAIError, GenAIModel, GenerativeModel, VertexAIError, VertexAIErrorCode, VertexAIModel, getGenerativeModel, getImagenModel, vertexAIBackend } from "./api";
+import { GenAI, VertexAI, GenAIErrorCode } from "./public-types";
+
+function assertAssignable<T, _U extends T>(): void {};
+
+const fakeGenAI: GenAI = {
+  app: {
+    name: 'DEFAULT',
+    automaticDataCollectionEnabled: true,
+    options: {
+      apiKey: 'key',
+      projectId: 'my-project',
+      appId: 'app-id'
+    }
+  },
+  backend: vertexAIBackend('us-central1'),
+  location: 'us-central1'
+};
+
+const fakeVertexAI: VertexAI = fakeGenAI;
+
+describe('backwards-compatible types', () => {
+  it('GenAI is backwards compatible with VertexAI', () => {
+    assertAssignable<VertexAI, GenAI>();
+  });
+  it('GenAIError is backwards compatible with VertexAIError', () => {
+    assertAssignable<typeof VertexAIError, typeof GenAIError>();
+    const err = new VertexAIError(VertexAIErrorCode.ERROR, "");
+    expect(err).instanceOf(GenAIError);
+    expect(err).instanceOf(VertexAIError);
+  });
+  it('GenAIErrorCode is backwards compatible with VertexAIErrorCode', () => {
+    assertAssignable<VertexAIErrorCode, GenAIErrorCode>();
+    const errCode = GenAIErrorCode.ERROR;
+    expect(errCode).to.equal(VertexAIErrorCode.ERROR);
+  });
+  it('GenAIModel is backwards compatible with VertexAIModel', () => {
+    assertAssignable<typeof VertexAIModel, typeof GenAIModel>();
+
+    const model = new GenerativeModel(fakeGenAI, { model: 'model-name' });
+    expect(model).to.be.instanceOf(GenAIModel);
+    expect(model).to.be.instanceOf(VertexAIModel);
+  });
+});
+
+describe('backward-compatible functions', () => {
+  it ('getGenerativeModel', () => {
+    const model = getGenerativeModel(fakeVertexAI, { model: 'model-name' });
+    expect(model).to.be.instanceOf(GenAIModel);
+    expect(model).to.be.instanceOf(VertexAIModel);
+  });
+  it ('getImagenModel', () => {
+    const model = getImagenModel(fakeVertexAI, { model: 'model-name' });
+    expect(model).to.be.instanceOf(GenAIModel);
+    expect(model).to.be.instanceOf(VertexAIModel);
+  });
+});