fix: #5240 remove all additionalProperties for gemini (#5247)

Author: jeasonnow

libs/langchain-google-common/src/tests/utils.test.ts

@@ -10,13 +10,15 @@ test("zodToGeminiParameters can convert zod schema to gemini schema", () => {
         .describe("The type of operation to execute"),
       number1: z.number().describe("The first number to operate on."),
       number2: z.number().describe("The second number to operate on."),
+      childObject: z.object({}),
     })
     .describe("A simple calculator tool");
 
   const convertedSchema = zodToGeminiParameters(zodSchema);
 
   expect(convertedSchema.type).toBe("object");
   expect(convertedSchema.description).toBe("A simple calculator tool");
+  expect(convertedSchema).not.toContain("additionalProperties");
   expect(convertedSchema.properties).toEqual({
     operation: {
       type: "string",
@@ -31,6 +33,15 @@ test("zodToGeminiParameters can convert zod schema to gemini schema", () => {
       type: "number",
       description: "The second number to operate on.",
     },
+    childObject: {
+      type: "object",
+      properties: {},
+    },
   });
-  expect(convertedSchema.required).toEqual(["operation", "number1", "number2"]);
+  expect(convertedSchema.required).toEqual([
+    "operation",
+    "number1",
+    "number2",
+    "childObject",
+  ]);
 });

libs/langchain-google-common/src/types.ts

@@ -274,3 +274,13 @@ export interface GoogleAISafetyHandler {
 export interface GoogleAISafetyParams {
   safetyHandler?: GoogleAISafetyHandler;
 }
+
+export type GeminiJsonSchema = Record<string, unknown> & {
+  properties?: Record<string, GeminiJsonSchema>;
+  type: GeminiFunctionSchemaType;
+};
+
+export interface GeminiJsonSchemaDirty extends GeminiJsonSchema {
+  properties?: Record<string, GeminiJsonSchemaDirty>;
+  additionalProperties?: boolean;
+}

libs/langchain-google-common/src/utils/zod_to_gemini_parameters.ts

@@ -2,7 +2,41 @@
 
 import type { z } from "zod";
 import { zodToJsonSchema } from "zod-to-json-schema";
-import { GeminiFunctionSchema } from "../types.js";
+import {
+  GeminiFunctionSchema,
+  GeminiJsonSchema,
+  GeminiJsonSchemaDirty,
+} from "../types.js";
+
+function removeAdditionalProperties(
+  schema: GeminiJsonSchemaDirty
+): GeminiJsonSchema {
+  const updatedSchema: GeminiJsonSchemaDirty = { ...schema };
+  if (Object.hasOwn(updatedSchema, "additionalProperties")) {
+    delete updatedSchema.additionalProperties;
+  }
+  if (updatedSchema.properties) {
+    const keys = Object.keys(updatedSchema.properties);
+    removeProperties(updatedSchema.properties, keys, 0);
+  }
+
+  return updatedSchema;
+}
+
+function removeProperties(
+  properties: Record<string, GeminiJsonSchemaDirty>,
+  keys: string[],
+  index: number
+): void {
+  if (index >= keys.length) {
+    return;
+  }
+
+  const key = keys[index];
+  // eslint-disable-next-line no-param-reassign
+  properties[key] = removeAdditionalProperties(properties[key]);
+  removeProperties(properties, keys, index + 1);
+}
 
 export function zodToGeminiParameters(
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -11,8 +45,11 @@ export function zodToGeminiParameters(
   // Gemini doesn't accept either the $schema or additionalProperties
   // attributes, so we need to explicitly remove them.
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const jsonSchema = zodToJsonSchema(zodObj) as any;
-  const { $schema, additionalProperties, ...rest } = jsonSchema;
+  // const jsonSchema = zodToJsonSchema(zodObj) as any;
+  const jsonSchema = removeAdditionalProperties(
+    zodToJsonSchema(zodObj) as GeminiJsonSchemaDirty
+  );
+  const { $schema, ...rest } = jsonSchema;
 
   return rest;
 }