import { describe, expect, it } from "vitest";
import { transformMessages } from "../src/providers/transform-messages.js";
import type { AssistantMessage, Message, Model, ToolCall } from "../src/types.js";
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-4.5",
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,
};
}
function makeAssistantMessage(content: AssistantMessage["content"]): AssistantMessage {
return {
role: "assistant",
content,
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(),
};
}
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;
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();
});
it("adds synthetic tool results for trailing orphaned tool calls", () => {
const model = makeCopilotClaudeModel();
const messages: Message[] = [
{ role: "user", content: "read the file", timestamp: Date.now() },
makeAssistantMessage([
{
type: "toolCall",
id: "call_123|fc_123",
name: "read",
arguments: { path: "README.md" },
},
]),
];
const result = transformMessages(messages, model, anthropicNormalizeToolCallId);
const lastMessage = result[result.length - 1];
expect(lastMessage).toMatchObject({
role: "toolResult",
toolCallId: "call_123_fc_123",
toolName: "read",
isError: true,
content: [{ type: "text", text: "No result provided" }],
});
});
it("adds synthetic results only for trailing tool calls that are still missing results", () => {
const model = makeCopilotClaudeModel();
const messages: Message[] = [
{ role: "user", content: "run commands", timestamp: Date.now() },
makeAssistantMessage([
{ type: "toolCall", id: "call_1|fc_1", name: "read", arguments: { path: "README.md" } },
{ type: "toolCall", id: "call_2|fc_2", name: "bash", arguments: { command: "pwd" } },
]),
{
role: "toolResult",
toolCallId: "call_1|fc_1",
toolName: "read",
content: [{ type: "text", text: "done" }],
isError: false,
timestamp: Date.now(),
},
];
const result = transformMessages(messages, model, anthropicNormalizeToolCallId);
const syntheticResults = result.filter((message) => message.role === "toolResult" && message.isError);
expect(syntheticResults).toHaveLength(1);
expect(syntheticResults[0]).toMatchObject({
role: "toolResult",
toolCallId: "call_2_fc_2",
toolName: "bash",
content: [{ type: "text", text: "No result provided" }],
});
});
});