testing-core-processors

name	testing-core-processors
description	Use when writing or debugging integration tests for error processors in packages/core/src/processors/. Covers the MockLanguageModelV2 pattern for simulating API errors and verifying retry behavior, plus the build prerequisites for focused vitest runs.

Testing Core Error Processors

How to write integration tests for error processors in packages/core/src/processors/.

Prerequisites

• Build core before running tests: pnpm build:core (from repo root)
• If focused vitest runs fail to resolve @internal/test-utils/setup, the build step was skipped

Mock Model Pattern

Use MockLanguageModelV2 from @internal/ai-sdk-v5/test to simulate API errors and verify retry behavior.

import { APICallError } from '@internal/ai-sdk-v5';
import { convertArrayToReadableStream, MockLanguageModelV2 } from '@internal/ai-sdk-v5/test';

// Track calls and captured prompts
let callCount = 0;
const receivedPrompts: any[] = [];

const model = new MockLanguageModelV2({
  doGenerate: async ({ prompt }) => {
    callCount++;
    receivedPrompts.(.(.(prompt)));
     (callCount === ) {
        ({
        : ,
        : ,
        : {},
        : ,
        : ,
        : ,
      });
    }
     {
      : { : , : {} },
      : ,
      : { : , : , :  },
      : [{ : , :  }],
      : [],
    };
  },
  :  ({ prompt }) => {
    
    
     {
      : { : , : {} },
      : [],
      : ([
        { : , : [] },
        { : , : , : , :  () },
        { : , :  },
        { : , : , :  },
        { : , :  },
        { : , : , : { : , : , :  } },
      ]),
    };
  },
});