messages: AgentMessage[],

errorMessage: string,

): Array<{ type: string; text?: string; data?: string }> {

const pruned = pruneProcessedHistoryImages(messages);

expect(pruned).not.toBeNull();

expect(pruned).not.toBe(messages);

const content = expectArrayMessageContent(pruned?.[0], errorMessage);

const pruned = expectPrunedMessages(messages);

const content = expectArrayMessageContent(pruned[0], errorMessage);

expect(content).toHaveLength(2);

expect(content[1]).toMatchObject({ type: "text", text: PRUNED_HISTORY_IMAGE_MARKER });

return content;

}

function expectPrunedMessages(messages: AgentMessage[]): AgentMessage[] {

const pruned = pruneProcessedHistoryImages(messages);

expect(pruned).toEqual(expect.any(Array));

if (!pruned) {

throw new Error("expected pruned history messages");

}

expect(pruned).not.toBe(messages);

return pruned;

}

function expectImageMessagePreserved(messages: AgentMessage[], errorMessage: string) {

const pruned = pruneProcessedHistoryImages(messages);

...oldEnoughTail(),

];

const pruned = pruneProcessedHistoryImages(messages);

const pruned = expectPrunedMessages(messages);

expect(pruned).not.toBeNull();

const content = expectArrayMessageContent(pruned?.[0], "expected user array content");

const content = expectArrayMessageContent(pruned[0], "expected user array content");

expect(content[0]?.text).toBe(

[

"old image",

...oldEnoughTail(),

];

const pruned = pruneProcessedHistoryImages(messages);

const pruned = expectPrunedMessages(messages);

expect(pruned).not.toBeNull();

const firstUser = pruned?.[0] as Extract<AgentMessage, { role: "user" }> | undefined;

const firstUser = pruned[0] as Extract<AgentMessage, { role: "user" }> | undefined;

expect(firstUser?.content).toBe(`please remember ${PRUNED_HISTORY_MEDIA_REFERENCE_MARKER}`);

const originalUser = messages[0] as Extract<AgentMessage, { role: "user" }> | undefined;

expect(originalUser?.content).toBe(

...oldEnoughTail(),

];

const pruned = pruneProcessedHistoryImages(messages);

const pruned = expectPrunedMessages(messages);

expect(pruned).not.toBeNull();

const toolResult = pruned?.[0] as Extract<AgentMessage, { role: "toolResult" }> | undefined;

const toolResult = pruned[0] as Extract<AgentMessage, { role: "toolResult" }> | undefined;

expect(toolResult?.content).toBe(`previous ${PRUNED_HISTORY_MEDIA_REFERENCE_MARKER} result`);

const originalToolResult = messages[0] as

| Extract<AgentMessage, { role: "toolResult" }>

assistantTurn(),

];

const pruned = pruneProcessedHistoryImages(messages);

expect(pruned).not.toBeNull();

const pruned = expectPrunedMessages(messages);

const oldContent = expectArrayMessageContent(pruned?.[0], "expected old user content");

const oldContent = expectArrayMessageContent(pruned[0], "expected old user content");

expect(oldContent[1]).toMatchObject({ type: "text", text: PRUNED_HISTORY_IMAGE_MARKER });

const recentContent = expectArrayMessageContent(pruned?.[6], "expected recent user content");

const recentContent = expectArrayMessageContent(pruned[6], "expected recent user content");

expect(recentContent[1]).toMatchObject({ type: "image", data: "abc" });

const originalOldContent = expectArrayMessageContent(