test(unit): add schema description too long error test

code/src/models/openai.ts

@@ -142,3 +142,9 @@ export class OpenAIModelHandler extends GeneralModelHandler<OpenAIModelSettings>
         return functionArguments || null;
     };
 }
+
+/** Used for unit testing */
+// eslint-disable-next-line no-underscore-dangle
+export const _private = {
+    wrapInOpenaiError,
+};

code/test/unit/models/openai.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, test } from 'vitest';
+
+import { DESCRIPTION_LENGTH_ERROR_LOG_MESSAGE, NonRetryableOpenaiAPIError } from '../../../src/errors';
+import { _private } from '../../../src/models/openai';
+import { LangchainError } from '../../../src/types/langchain-types';
+
+const { wrapInOpenaiError } = _private;
+
+describe('wrapInOpenaiError', () => {
+    test('should return help error message for "too long function description" error', () => {
+        const error = new Error() as LangchainError;
+        error.error = { message: "'blah blah too long blah' is too long - 'functions.0.description'" };
+        error.status = 400;
+
+        const wrappedError = wrapInOpenaiError(error as LangchainError);
+
+        expect(wrappedError).toBeInstanceOf(NonRetryableOpenaiAPIError);
+        expect(wrappedError.message).toBe(`OpenaiAPIError: ${DESCRIPTION_LENGTH_ERROR_LOG_MESSAGE}`);
+    });
+});