fix(js/ai/prompt): delete null descriptions returned by dotprompt (#1687

)

js/ai/src/prompt.ts

@@ -736,6 +736,12 @@ function loadPrompt(
       if (variant) {
         promptMetadata.variant = variant;
       }
+
+      // dotprompt can set null description on the schema, which can confuse downstream schema consumers
+      if (promptMetadata.output?.schema?.description === null) {
+        delete promptMetadata.output?.schema?.description;
+      }
+
       return {
         name: registryDefinitionKey(name, variant ?? undefined, ns),
         model: promptMetadata.model,

js/core/tests/schema_test.ts

@@ -20,6 +20,7 @@ import { describe, it } from 'node:test';
 import {
   ValidationError,
   parseSchema,
+  toJsonSchema,
   validateSchema,
   z,
 } from '../src/schema.js';
@@ -138,3 +139,26 @@ describe('parse()', () => {
     );
   });
 });
+
+describe('toJsonSchema', () => {
+  it('converts zod to JSON schema', async () => {
+    assert.deepStrictEqual(
+      toJsonSchema({
+        schema: z.object({
+          output: z.string(),
+        }),
+      }),
+      {
+        $schema: 'http://json-schema.org/draft-07/schema#',
+        additionalProperties: true,
+        properties: {
+          output: {
+            type: 'string',
+          },
+        },
+        required: ['output'],
+        type: 'object',
+      }
+    );
+  });
+});

js/genkit/tests/prompts/schemaRef.prompt

@@ -0,0 +1,9 @@
+---
+model: googleai/gemini-1.5-flash
+input:
+  schema: myInputSchema
+output:
+  schema: myOutputSchema
+---
+
+Write a poem about {{foo}}.

js/genkit/tests/prompts_test.ts

@@ -900,6 +900,8 @@ describe.only('prompt', () => {
     });
     defineEchoModel(ai);
     pm = defineProgrammableModel(ai);
+    ai.defineSchema('myInputSchema', z.object({ foo: z.string() }));
+    ai.defineSchema('myOutputSchema', z.object({ output: z.string() }));
   });
 
   it('loads from from the folder', async () => {
@@ -1014,6 +1016,23 @@ describe.only('prompt', () => {
     });
   });
 
+  it('resolved schema refs', async () => {
+    const prompt = ai.prompt('schemaRef');
+
+    const rendered = await prompt.render({ foo: 'bar' });
+    assert.deepStrictEqual(rendered.output?.jsonSchema, {
+      $schema: 'http://json-schema.org/draft-07/schema#',
+      additionalProperties: true,
+      properties: {
+        output: {
+          type: 'string',
+        },
+      },
+      required: ['output'],
+      type: 'object',
+    });
+  });
+
   it('loads a varaint from from the folder', async () => {
     const testPrompt = ai.prompt('test', { variant: 'variant' }); // see tests/prompts folder