clanker-agent/packages/ai/test/transform-messages-copilot-openai-to-anthropic.test.ts

import { describe, expect, it } from "vitest";
import { transformMessages } from "../src/providers/transform-messages.js";
import type {
  AssistantMessage,
  Message,
  Model,
  ToolCall,
} from "../src/types.js";

// Normalize function matching what anthropic.ts uses
function anthropicNormalizeToolCallId(
  id: string,
  _model: Model<"anthropic-messages">,
  _source: AssistantMessage,
): string {
  return id.replace(/[^a-zA-Z0-9_-]/g, "_").slice(0, 64);
}

function makeCopilotClaudeModel(): Model<"anthropic-messages"> {
  return {
    id: "claude-sonnet-4",
    name: "Claude Sonnet 4",
    api: "anthropic-messages",
    provider: "github-copilot",
    baseUrl: "https://api.individual.githubcopilot.com",
    reasoning: true,
    input: ["text", "image"],
    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
    contextWindow: 128000,
    maxTokens: 16000,
  };
}

describe("OpenAI to Anthropic session migration for Copilot Claude", () => {
  it("converts thinking blocks to plain text when source model differs", () => {
    const model = makeCopilotClaudeModel();
    const messages: Message[] = [
      { role: "user", content: "hello", timestamp: Date.now() },
      {
        role: "assistant",
        content: [
          {
            type: "thinking",
            thinking: "Let me think about this...",
            thinkingSignature: "reasoning_content",
          },
          { type: "text", text: "Hi there!" },
        ],
        api: "openai-completions",
        provider: "github-copilot",
        model: "gpt-4o",
        usage: {
          input: 0,
          output: 0,
          cacheRead: 0,
          cacheWrite: 0,
          totalTokens: 0,
          cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
        },
        stopReason: "stop",
        timestamp: Date.now(),
      },
    ];

    const result = transformMessages(
      messages,
      model,
      anthropicNormalizeToolCallId,
    );
    const assistantMsg = result.find(
      (m) => m.role === "assistant",
    ) as AssistantMessage;

    // Thinking block should be converted to text since models differ
    const textBlocks = assistantMsg.content.filter((b) => b.type === "text");
    const thinkingBlocks = assistantMsg.content.filter(
      (b) => b.type === "thinking",
    );
    expect(thinkingBlocks).toHaveLength(0);
    expect(textBlocks.length).toBeGreaterThanOrEqual(2);
  });

  it("removes thoughtSignature from tool calls when migrating between models", () => {
    const model = makeCopilotClaudeModel();
    const messages: Message[] = [
      { role: "user", content: "run a command", timestamp: Date.now() },
      {
        role: "assistant",
        content: [
          {
            type: "toolCall",
            id: "call_123",
            name: "bash",
            arguments: { command: "ls" },
            thoughtSignature: JSON.stringify({
              type: "reasoning.encrypted",
              id: "call_123",
              data: "encrypted",
            }),
          },
        ],
        api: "openai-responses",
        provider: "github-copilot",
        model: "gpt-5",
        usage: {
          input: 0,
          output: 0,
          cacheRead: 0,
          cacheWrite: 0,
          totalTokens: 0,
          cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
        },
        stopReason: "toolUse",
        timestamp: Date.now(),
      },
      {
        role: "toolResult",
        toolCallId: "call_123",
        toolName: "bash",
        content: [{ type: "text", text: "output" }],
        isError: false,
        timestamp: Date.now(),
      },
    ];

    const result = transformMessages(
      messages,
      model,
      anthropicNormalizeToolCallId,
    );
    const assistantMsg = result.find(
      (m) => m.role === "assistant",
    ) as AssistantMessage;
    const toolCall = assistantMsg.content.find(
      (b) => b.type === "toolCall",
    ) as ToolCall;

    expect(toolCall.thoughtSignature).toBeUndefined();
  });
});